Commit graph

82,373 commits

Author SHA1 Message Date
Tetsuo Handa
6121b7564c net: can: j1939: j1939_xtp_rx_rts_session_active(): deactivate session upon receiving the second rts
commit 1809c82aa0 upstream.

Since j1939_session_deactivate_activate_next() in j1939_tp_rxtimer() is
called only when the timer is enabled, we need to call
j1939_session_deactivate_activate_next() if we cancelled the timer.
Otherwise, refcount for j1939_session leaks, which will later appear as

| unregister_netdevice: waiting for vcan0 to become free. Usage count = 2.

problem.

Reported-by: syzbot <syzbot+881d65229ca4f9ae8c84@syzkaller.appspotmail.com>
Closes: https://syzkaller.appspot.com/bug?extid=881d65229ca4f9ae8c84
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Tested-by: Oleksij Rempel <o.rempel@pengutronix.de>
Acked-by: Oleksij Rempel <o.rempel@pengutronix.de>
Fixes: 9d71dd0c70 ("can: add support of SAE J1939 protocol")
Link: https://patch.msgid.link/b1212653-8fa1-44e1-be9d-12f950fb3a07@I-love.SAKURA.ne.jp
Cc: stable@vger.kernel.org
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-01-23 11:21:24 +01:00
Eric Dumazet
e9d8f11652 net/sched: sch_qfq: do not free existing class in qfq_change_class()
[ Upstream commit 3879cffd9d ]

Fixes qfq_change_class() error case.

cl->qdisc and cl should only be freed if a new class and qdisc
were allocated, or we risk various UAF.

Fixes: 462dbc9101 ("pkt_sched: QFQ Plus: fair-queueing service at DRR cost")
Reported-by: syzbot+07f3f38f723c335f106d@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/6965351d.050a0220.eaf7.00c5.GAE@google.com/T/#u
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://patch.msgid.link/20260112175656.17605-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-23 11:21:18 +01:00
Kuniyuki Iwashima
8b6dcb565e ipv6: Fix use-after-free in inet6_addr_del().
[ Upstream commit ddf96c393a ]

syzbot reported use-after-free of inet6_ifaddr in
inet6_addr_del(). [0]

The cited commit accidentally moved ipv6_del_addr() for
mngtmpaddr before reading its ifp->flags for temporary
addresses in inet6_addr_del().

Let's move ipv6_del_addr() down to fix the UAF.

[0]:
BUG: KASAN: slab-use-after-free in inet6_addr_del.constprop.0+0x67a/0x6b0 net/ipv6/addrconf.c:3117
Read of size 4 at addr ffff88807b89c86c by task syz.3.1618/9593

CPU: 0 UID: 0 PID: 9593 Comm: syz.3.1618 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xcd/0x630 mm/kasan/report.c:482
 kasan_report+0xe0/0x110 mm/kasan/report.c:595
 inet6_addr_del.constprop.0+0x67a/0x6b0 net/ipv6/addrconf.c:3117
 addrconf_del_ifaddr+0x11e/0x190 net/ipv6/addrconf.c:3181
 inet6_ioctl+0x1e5/0x2b0 net/ipv6/af_inet6.c:582
 sock_do_ioctl+0x118/0x280 net/socket.c:1254
 sock_ioctl+0x227/0x6b0 net/socket.c:1375
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl fs/ioctl.c:583 [inline]
 __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f164cf8f749
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f164de64038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f164d1e5fa0 RCX: 00007f164cf8f749
RDX: 0000200000000000 RSI: 0000000000008936 RDI: 0000000000000003
RBP: 00007f164d013f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f164d1e6038 R14: 00007f164d1e5fa0 R15: 00007ffde15c8288
 </TASK>

Allocated by task 9593:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:56
 kasan_save_track+0x14/0x30 mm/kasan/common.c:77
 poison_kmalloc_redzone mm/kasan/common.c:397 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:414
 kmalloc_noprof include/linux/slab.h:957 [inline]
 kzalloc_noprof include/linux/slab.h:1094 [inline]
 ipv6_add_addr+0x4e3/0x2010 net/ipv6/addrconf.c:1120
 inet6_addr_add+0x256/0x9b0 net/ipv6/addrconf.c:3050
 addrconf_add_ifaddr+0x1fc/0x450 net/ipv6/addrconf.c:3160
 inet6_ioctl+0x103/0x2b0 net/ipv6/af_inet6.c:580
 sock_do_ioctl+0x118/0x280 net/socket.c:1254
 sock_ioctl+0x227/0x6b0 net/socket.c:1375
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl fs/ioctl.c:583 [inline]
 __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 6099:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:56
 kasan_save_track+0x14/0x30 mm/kasan/common.c:77
 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:252 [inline]
 __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:284
 kasan_slab_free include/linux/kasan.h:234 [inline]
 slab_free_hook mm/slub.c:2540 [inline]
 slab_free_freelist_hook mm/slub.c:2569 [inline]
 slab_free_bulk mm/slub.c:6696 [inline]
 kmem_cache_free_bulk mm/slub.c:7383 [inline]
 kmem_cache_free_bulk+0x2bf/0x680 mm/slub.c:7362
 kfree_bulk include/linux/slab.h:830 [inline]
 kvfree_rcu_bulk+0x1b7/0x1e0 mm/slab_common.c:1523
 kvfree_rcu_drain_ready mm/slab_common.c:1728 [inline]
 kfree_rcu_monitor+0x1d0/0x2f0 mm/slab_common.c:1801
 process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257
 process_scheduled_works kernel/workqueue.c:3340 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246

Fixes: 00b5b7aab9 ("net/ipv6: delete temporary address if mngtmpaddr is removed or unmanaged")
Reported-by: syzbot+72e610f4f1a930ca9d8a@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/696598e9.050a0220.3be5c5.0009.GAE@google.com/
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Hangbin Liu <liuhangbin@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260113010538.2019411-1-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-23 11:21:18 +01:00
Eric Dumazet
722de94521 dst: fix races in rt6_uncached_list_del() and rt_del_uncached_list()
[ Upstream commit 9a6f0c4d57 ]

syzbot was able to crash the kernel in rt6_uncached_list_flush_dev()
in an interesting way [1]

Crash happens in list_del_init()/INIT_LIST_HEAD() while writing
list->prev, while the prior write on list->next went well.

static inline void INIT_LIST_HEAD(struct list_head *list)
{
	WRITE_ONCE(list->next, list); // This went well
	WRITE_ONCE(list->prev, list); // Crash, @list has been freed.
}

Issue here is that rt6_uncached_list_del() did not attempt to lock
ul->lock, as list_empty(&rt->dst.rt_uncached) returned
true because the WRITE_ONCE(list->next, list) happened on the other CPU.

We might use list_del_init_careful() and list_empty_careful(),
or make sure rt6_uncached_list_del() always grabs the spinlock
whenever rt->dst.rt_uncached_list has been set.

A similar fix is neeed for IPv4.

[1]

 BUG: KASAN: slab-use-after-free in INIT_LIST_HEAD include/linux/list.h:46 [inline]
 BUG: KASAN: slab-use-after-free in list_del_init include/linux/list.h:296 [inline]
 BUG: KASAN: slab-use-after-free in rt6_uncached_list_flush_dev net/ipv6/route.c:191 [inline]
 BUG: KASAN: slab-use-after-free in rt6_disable_ip+0x633/0x730 net/ipv6/route.c:5020
Write of size 8 at addr ffff8880294cfa78 by task kworker/u8:14/3450

CPU: 0 UID: 0 PID: 3450 Comm: kworker/u8:14 Tainted: G             L      syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: netns cleanup_net
Call Trace:
 <TASK>
  dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
  print_address_description mm/kasan/report.c:378 [inline]
  print_report+0xca/0x240 mm/kasan/report.c:482
  kasan_report+0x118/0x150 mm/kasan/report.c:595
  INIT_LIST_HEAD include/linux/list.h:46 [inline]
  list_del_init include/linux/list.h:296 [inline]
  rt6_uncached_list_flush_dev net/ipv6/route.c:191 [inline]
  rt6_disable_ip+0x633/0x730 net/ipv6/route.c:5020
  addrconf_ifdown+0x143/0x18a0 net/ipv6/addrconf.c:3853
 addrconf_notify+0x1bc/0x1050 net/ipv6/addrconf.c:-1
  notifier_call_chain+0x19d/0x3a0 kernel/notifier.c:85
  call_netdevice_notifiers_extack net/core/dev.c:2268 [inline]
  call_netdevice_notifiers net/core/dev.c:2282 [inline]
  netif_close_many+0x29c/0x410 net/core/dev.c:1785
  unregister_netdevice_many_notify+0xb50/0x2330 net/core/dev.c:12353
  ops_exit_rtnl_list net/core/net_namespace.c:187 [inline]
  ops_undo_list+0x3dc/0x990 net/core/net_namespace.c:248
  cleanup_net+0x4de/0x7b0 net/core/net_namespace.c:696
  process_one_work kernel/workqueue.c:3257 [inline]
  process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
  worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
  kthread+0x711/0x8a0 kernel/kthread.c:463
  ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
  ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>

Allocated by task 803:
  kasan_save_stack mm/kasan/common.c:57 [inline]
  kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
  unpoison_slab_object mm/kasan/common.c:340 [inline]
  __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366
  kasan_slab_alloc include/linux/kasan.h:253 [inline]
  slab_post_alloc_hook mm/slub.c:4953 [inline]
  slab_alloc_node mm/slub.c:5263 [inline]
  kmem_cache_alloc_noprof+0x18d/0x6c0 mm/slub.c:5270
  dst_alloc+0x105/0x170 net/core/dst.c:89
  ip6_dst_alloc net/ipv6/route.c:342 [inline]
  icmp6_dst_alloc+0x75/0x460 net/ipv6/route.c:3333
  mld_sendpack+0x683/0xe60 net/ipv6/mcast.c:1844
  mld_send_cr net/ipv6/mcast.c:2154 [inline]
  mld_ifc_work+0x83e/0xd60 net/ipv6/mcast.c:2693
  process_one_work kernel/workqueue.c:3257 [inline]
  process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
  worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
  kthread+0x711/0x8a0 kernel/kthread.c:463
  ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
  ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246

Freed by task 20:
  kasan_save_stack mm/kasan/common.c:57 [inline]
  kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
  kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
  poison_slab_object mm/kasan/common.c:253 [inline]
  __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
  kasan_slab_free include/linux/kasan.h:235 [inline]
  slab_free_hook mm/slub.c:2540 [inline]
  slab_free mm/slub.c:6670 [inline]
  kmem_cache_free+0x18f/0x8d0 mm/slub.c:6781
  dst_destroy+0x235/0x350 net/core/dst.c:121
  rcu_do_batch kernel/rcu/tree.c:2605 [inline]
  rcu_core kernel/rcu/tree.c:2857 [inline]
  rcu_cpu_kthread+0xba5/0x1af0 kernel/rcu/tree.c:2945
  smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160
  kthread+0x711/0x8a0 kernel/kthread.c:463
  ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
  ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246

Last potentially related work creation:
  kasan_save_stack+0x3e/0x60 mm/kasan/common.c:57
  kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556
  __call_rcu_common kernel/rcu/tree.c:3119 [inline]
  call_rcu+0xee/0x890 kernel/rcu/tree.c:3239
  refdst_drop include/net/dst.h:266 [inline]
  skb_dst_drop include/net/dst.h:278 [inline]
  skb_release_head_state+0x71/0x360 net/core/skbuff.c:1156
  skb_release_all net/core/skbuff.c:1180 [inline]
  __kfree_skb net/core/skbuff.c:1196 [inline]
  sk_skb_reason_drop+0xe9/0x170 net/core/skbuff.c:1234
  kfree_skb_reason include/linux/skbuff.h:1322 [inline]
  tcf_kfree_skb_list include/net/sch_generic.h:1127 [inline]
  __dev_xmit_skb net/core/dev.c:4260 [inline]
  __dev_queue_xmit+0x26aa/0x3210 net/core/dev.c:4785
  NF_HOOK_COND include/linux/netfilter.h:307 [inline]
  ip6_output+0x340/0x550 net/ipv6/ip6_output.c:247
  NF_HOOK+0x9e/0x380 include/linux/netfilter.h:318
  mld_sendpack+0x8d4/0xe60 net/ipv6/mcast.c:1855
  mld_send_cr net/ipv6/mcast.c:2154 [inline]
  mld_ifc_work+0x83e/0xd60 net/ipv6/mcast.c:2693
  process_one_work kernel/workqueue.c:3257 [inline]
  process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
  worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
  kthread+0x711/0x8a0 kernel/kthread.c:463
  ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
  ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246

The buggy address belongs to the object at ffff8880294cfa00
 which belongs to the cache ip6_dst_cache of size 232
The buggy address is located 120 bytes inside of
 freed 232-byte region [ffff8880294cfa00, ffff8880294cfae8)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x294cf
memcg:ffff88803536b781
flags: 0x80000000000000(node=0|zone=1)
page_type: f5(slab)
raw: 0080000000000000 ffff88802ff1c8c0 ffffea0000bf2bc0 dead000000000006
raw: 0000000000000000 00000000800c000c 00000000f5000000 ffff88803536b781
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x52820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 9, tgid 9 (kworker/0:0), ts 91119585830, free_ts 91088628818
  set_page_owner include/linux/page_owner.h:32 [inline]
  post_alloc_hook+0x234/0x290 mm/page_alloc.c:1857
  prep_new_page mm/page_alloc.c:1865 [inline]
  get_page_from_freelist+0x28c0/0x2960 mm/page_alloc.c:3915
  __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5210
  alloc_pages_mpol+0xd1/0x380 mm/mempolicy.c:2486
  alloc_slab_page mm/slub.c:3075 [inline]
  allocate_slab+0x86/0x3b0 mm/slub.c:3248
  new_slab mm/slub.c:3302 [inline]
  ___slab_alloc+0xb10/0x13e0 mm/slub.c:4656
  __slab_alloc+0xc6/0x1f0 mm/slub.c:4779
  __slab_alloc_node mm/slub.c:4855 [inline]
  slab_alloc_node mm/slub.c:5251 [inline]
  kmem_cache_alloc_noprof+0x101/0x6c0 mm/slub.c:5270
  dst_alloc+0x105/0x170 net/core/dst.c:89
  ip6_dst_alloc net/ipv6/route.c:342 [inline]
  icmp6_dst_alloc+0x75/0x460 net/ipv6/route.c:3333
  mld_sendpack+0x683/0xe60 net/ipv6/mcast.c:1844
  mld_send_cr net/ipv6/mcast.c:2154 [inline]
  mld_ifc_work+0x83e/0xd60 net/ipv6/mcast.c:2693
  process_one_work kernel/workqueue.c:3257 [inline]
  process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
  worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
  kthread+0x711/0x8a0 kernel/kthread.c:463
  ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
page last free pid 5859 tgid 5859 stack trace:
  reset_page_owner include/linux/page_owner.h:25 [inline]
  free_pages_prepare mm/page_alloc.c:1406 [inline]
  __free_frozen_pages+0xfe1/0x1170 mm/page_alloc.c:2943
  discard_slab mm/slub.c:3346 [inline]
  __put_partials+0x149/0x170 mm/slub.c:3886
  __slab_free+0x2af/0x330 mm/slub.c:5952
  qlink_free mm/kasan/quarantine.c:163 [inline]
  qlist_free_all+0x97/0x100 mm/kasan/quarantine.c:179
  kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
  __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350
  kasan_slab_alloc include/linux/kasan.h:253 [inline]
  slab_post_alloc_hook mm/slub.c:4953 [inline]
  slab_alloc_node mm/slub.c:5263 [inline]
  kmem_cache_alloc_noprof+0x18d/0x6c0 mm/slub.c:5270
  getname_flags+0xb8/0x540 fs/namei.c:146
  getname include/linux/fs.h:2498 [inline]
  do_sys_openat2+0xbc/0x200 fs/open.c:1426
  do_sys_open fs/open.c:1436 [inline]
  __do_sys_openat fs/open.c:1452 [inline]
  __se_sys_openat fs/open.c:1447 [inline]
  __x64_sys_openat+0x138/0x170 fs/open.c:1447
  do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
  do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94

Fixes: 8d0b94afdc ("ipv6: Keep track of DST_NOCACHE routes in case of iface down/unregister")
Fixes: 78df76a065 ("ipv4: take rt_uncached_lock only if needed")
Reported-by: syzbot+179fc225724092b8b2b2@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/6964cdf2.050a0220.eaf7.009d.GAE@google.com/T/#u
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Martin KaFai Lau <martin.lau@kernel.org>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/20260112103825.3810713-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-23 11:21:18 +01:00
Eric Dumazet
554201ed0a ipv4: ip_gre: make ipgre_header() robust
[ Upstream commit e67c577d89 ]

Analog to commit db5b4e39c4 ("ip6_gre: make ip6gre_header() robust")

Over the years, syzbot found many ways to crash the kernel
in ipgre_header() [1].

This involves team or bonding drivers ability to dynamically
change their dev->needed_headroom and/or dev->hard_header_len

In this particular crash mld_newpack() allocated an skb
with a too small reserve/headroom, and by the time mld_sendpack()
was called, syzbot managed to attach an ipgre device.

[1]
skbuff: skb_under_panic: text:ffffffff89ea3cb7 len:2030915468 put:2030915372 head:ffff888058b43000 data:ffff887fdfa6e194 tail:0x120 end:0x6c0 dev:team0
 kernel BUG at net/core/skbuff.c:213 !
Oops: invalid opcode: 0000 [#1] SMP KASAN PTI
CPU: 1 UID: 0 PID: 1322 Comm: kworker/1:9 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: mld mld_ifc_work
 RIP: 0010:skb_panic+0x157/0x160 net/core/skbuff.c:213
Call Trace:
 <TASK>
  skb_under_panic net/core/skbuff.c:223 [inline]
  skb_push+0xc3/0xe0 net/core/skbuff.c:2641
  ipgre_header+0x67/0x290 net/ipv4/ip_gre.c:897
  dev_hard_header include/linux/netdevice.h:3436 [inline]
  neigh_connected_output+0x286/0x460 net/core/neighbour.c:1618
  NF_HOOK_COND include/linux/netfilter.h:307 [inline]
  ip6_output+0x340/0x550 net/ipv6/ip6_output.c:247
  NF_HOOK+0x9e/0x380 include/linux/netfilter.h:318
  mld_sendpack+0x8d4/0xe60 net/ipv6/mcast.c:1855
  mld_send_cr net/ipv6/mcast.c:2154 [inline]
  mld_ifc_work+0x83e/0xd60 net/ipv6/mcast.c:2693
  process_one_work kernel/workqueue.c:3257 [inline]
  process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
  worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
  kthread+0x711/0x8a0 kernel/kthread.c:463
  ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
  ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246

Fixes: c544193214 ("GRE: Refactor GRE tunneling code.")
Reported-by: syzbot+7c134e1c3aa3283790b9@syzkaller.appspotmail.com
Closes: https://www.spinics.net/lists/netdev/msg1147302.html
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260108190214.1667040-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-23 11:21:16 +01:00
Eric Dumazet
da6d0370eb net: update netdev_lock_{type,name}
[ Upstream commit eb74c19fe1 ]

Add missing entries in netdev_lock_type[] and netdev_lock_name[] :

CAN, MCTP, RAWIP, CAIF, IP6GRE, 6LOWPAN, NETLINK, VSOCKMON,
IEEE802154_MONITOR.

Also add a WARN_ONCE() in netdev_lock_pos() to help future bug hunting
next time a protocol is added without updating these arrays.

Fixes: 1a33e10e4a ("net: partially revert dynamic lockdep key changes")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260108093244.830280-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-23 11:21:16 +01:00
Eric Dumazet
b9f915340f ip6_tunnel: use skb_vlan_inet_prepare() in __ip6_tnl_rcv()
[ Upstream commit 81c734dae2 ]

Blamed commit did not take care of VLAN encapsulations
as spotted by syzbot [1].

Use skb_vlan_inet_prepare() instead of pskb_inet_may_pull().

[1]
 BUG: KMSAN: uninit-value in __INET_ECN_decapsulate include/net/inet_ecn.h:253 [inline]
 BUG: KMSAN: uninit-value in INET_ECN_decapsulate include/net/inet_ecn.h:275 [inline]
 BUG: KMSAN: uninit-value in IP6_ECN_decapsulate+0x7a8/0x1fa0 include/net/inet_ecn.h:321
  __INET_ECN_decapsulate include/net/inet_ecn.h:253 [inline]
  INET_ECN_decapsulate include/net/inet_ecn.h:275 [inline]
  IP6_ECN_decapsulate+0x7a8/0x1fa0 include/net/inet_ecn.h:321
  ip6ip6_dscp_ecn_decapsulate+0x16f/0x1b0 net/ipv6/ip6_tunnel.c:729
  __ip6_tnl_rcv+0xed9/0x1b50 net/ipv6/ip6_tunnel.c:860
  ip6_tnl_rcv+0xc3/0x100 net/ipv6/ip6_tunnel.c:903
 gre_rcv+0x1529/0x1b90 net/ipv6/ip6_gre.c:-1
  ip6_protocol_deliver_rcu+0x1c89/0x2c60 net/ipv6/ip6_input.c:438
  ip6_input_finish+0x1f4/0x4a0 net/ipv6/ip6_input.c:489
  NF_HOOK include/linux/netfilter.h:318 [inline]
  ip6_input+0x9c/0x330 net/ipv6/ip6_input.c:500
  ip6_mc_input+0x7ca/0xc10 net/ipv6/ip6_input.c:590
  dst_input include/net/dst.h:474 [inline]
  ip6_rcv_finish+0x958/0x990 net/ipv6/ip6_input.c:79
  NF_HOOK include/linux/netfilter.h:318 [inline]
  ipv6_rcv+0xf1/0x3c0 net/ipv6/ip6_input.c:311
  __netif_receive_skb_one_core net/core/dev.c:6139 [inline]
  __netif_receive_skb+0x1df/0xac0 net/core/dev.c:6252
  netif_receive_skb_internal net/core/dev.c:6338 [inline]
  netif_receive_skb+0x57/0x630 net/core/dev.c:6397
  tun_rx_batched+0x1df/0x980 drivers/net/tun.c:1485
  tun_get_user+0x5c0e/0x6c60 drivers/net/tun.c:1953
  tun_chr_write_iter+0x3e9/0x5c0 drivers/net/tun.c:1999
  new_sync_write fs/read_write.c:593 [inline]
  vfs_write+0xbe2/0x15d0 fs/read_write.c:686
  ksys_write fs/read_write.c:738 [inline]
  __do_sys_write fs/read_write.c:749 [inline]
  __se_sys_write fs/read_write.c:746 [inline]
  __x64_sys_write+0x1fb/0x4d0 fs/read_write.c:746
  x64_sys_call+0x30ab/0x3e70 arch/x86/include/generated/asm/syscalls_64.h:2
  do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
  do_syscall_64+0xd3/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Uninit was created at:
  slab_post_alloc_hook mm/slub.c:4960 [inline]
  slab_alloc_node mm/slub.c:5263 [inline]
  kmem_cache_alloc_node_noprof+0x9e7/0x17a0 mm/slub.c:5315
  kmalloc_reserve+0x13c/0x4b0 net/core/skbuff.c:586
  __alloc_skb+0x805/0x1040 net/core/skbuff.c:690
  alloc_skb include/linux/skbuff.h:1383 [inline]
  alloc_skb_with_frags+0xc5/0xa60 net/core/skbuff.c:6712
  sock_alloc_send_pskb+0xacc/0xc60 net/core/sock.c:2995
  tun_alloc_skb drivers/net/tun.c:1461 [inline]
  tun_get_user+0x1142/0x6c60 drivers/net/tun.c:1794
  tun_chr_write_iter+0x3e9/0x5c0 drivers/net/tun.c:1999
  new_sync_write fs/read_write.c:593 [inline]
  vfs_write+0xbe2/0x15d0 fs/read_write.c:686
  ksys_write fs/read_write.c:738 [inline]
  __do_sys_write fs/read_write.c:749 [inline]
  __se_sys_write fs/read_write.c:746 [inline]
  __x64_sys_write+0x1fb/0x4d0 fs/read_write.c:746
  x64_sys_call+0x30ab/0x3e70 arch/x86/include/generated/asm/syscalls_64.h:2
  do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
  do_syscall_64+0xd3/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

CPU: 0 UID: 0 PID: 6465 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(none)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025

Fixes: 8d975c15c0 ("ip6_tunnel: make sure to pull inner header in __ip6_tnl_rcv()")
Reported-by: syzbot+d4dda070f833dc5dc89a@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/695e88b2.050a0220.1c677c.036d.GAE@google.com/T/#u
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260107163109.4188620-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-23 11:21:16 +01:00
Eric Dumazet
17071fb5cb net: bridge: annotate data-races around fdb->{updated,used}
[ Upstream commit b25a0b4a21 ]

fdb->updated and fdb->used are read and written locklessly.

Add READ_ONCE()/WRITE_ONCE() annotations.

Fixes: 31cbc39b63 ("net: bridge: add option to allow activity notifications for any fdb entries")
Reported-by: syzbot+bfab43087ad57222ce96@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/695e3d74.050a0220.1c677c.035f.GAE@google.com/
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20260108093806.834459-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-23 11:21:16 +01:00
Yang Li
3682517456 Bluetooth: hci_sync: enable PA Sync Lost event
[ Upstream commit ab749bfe6a ]

Enable the PA Sync Lost event mask to ensure PA sync loss is properly
reported and handled.

Fixes: 485e0626e5 ("Bluetooth: hci_event: Fix not handling PA Sync Lost event")
Signed-off-by: Yang Li <yang.li@amlogic.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-23 11:21:15 +01:00
Eric Dumazet
5584aa64e8 ipv4: ip_tunnel: spread netdev_lockdep_set_classes()
[ Upstream commit 872ac785e7 ]

Inspired by yet another syzbot report.

IPv6 tunnels call netdev_lockdep_set_classes() for each tunnel type,
while IPv4 currently centralizes netdev_lockdep_set_classes() call from
ip_tunnel_init().

Make ip_tunnel_init() a macro, so that we have different lockdep
classes per tunnel type.

Fixes: 0bef512012 ("net: add netdev_lockdep_set_classes() to virtual drivers")
Reported-by: syzbot+1240b33467289f5ab50b@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/695d439f.050a0220.1c677c.0347.GAE@google.com/T/#u
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260106172426.1760721-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-23 11:21:15 +01:00
Antony Antony
b7f9587f31 xfrm: set ipv4 no_pmtu_disc flag only on output sa when direction is set
[ Upstream commit c196def07b ]

The XFRM_STATE_NOPMTUDISC flag is only meaningful for output SAs, but
it was being applied regardless of the SA direction when the sysctl
ip_no_pmtu_disc is enabled. This can unintentionally affect input SAs.

Limit setting XFRM_STATE_NOPMTUDISC to output SAs when the SA direction
is configured.

Closes: https://github.com/strongswan/strongswan/issues/2946
Fixes: a4a87fa4e9 ("xfrm: Add Direction to the SA in or out")
Signed-off-by: Antony Antony <antony.antony@secunet.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-23 11:21:13 +01:00
Jianbo Liu
df1fae8626 xfrm: Fix inner mode lookup in tunnel mode GSO segmentation
[ Upstream commit 3d5221af9c ]

Commit 61fafbee6c ("xfrm: Determine inner GSO type from packet inner
protocol") attempted to fix GSO segmentation by reading the inner
protocol from XFRM_MODE_SKB_CB(skb)->protocol. This was incorrect
because the field holds the inner L4 protocol (TCP/UDP) instead of the
required tunnel protocol. Also, the memory location (shared by
XFRM_SKB_CB(skb) which could be overwritten by xfrm_replay_overflow())
is prone to corruption. This combination caused the kernel to select
the wrong inner mode and get the wrong address family.

The correct value is in xfrm_offload(skb)->proto, which is set from
the outer tunnel header's protocol field by esp[4|6]_gso_encap(). It
is initialized by xfrm[4|6]_tunnel_encap_add() to either IPPROTO_IPIP
or IPPROTO_IPV6, using xfrm_af2proto() and correctly reflects the
inner packet's address family.

Fixes: 61fafbee6c ("xfrm: Determine inner GSO type from packet inner protocol")
Signed-off-by: Jianbo Liu <jianbol@nvidia.com>
Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-23 11:21:13 +01:00
Tetsuo Handa
79dd3f1d9d can: j1939: make j1939_session_activate() fail if device is no longer registered
[ Upstream commit 5d5602236f ]

syzbot is still reporting

  unregister_netdevice: waiting for vcan0 to become free. Usage count = 2

even after commit 93a27b5891 ("can: j1939: add missing calls in
NETDEV_UNREGISTER notification handler") was added. A debug printk() patch
found that j1939_session_activate() can succeed even after
j1939_cancel_active_session() from j1939_netdev_notify(NETDEV_UNREGISTER)
has completed.

Since j1939_cancel_active_session() is processed with the session list lock
held, checking ndev->reg_state in j1939_session_activate() with the session
list lock held can reliably close the race window.

Reported-by: syzbot <syzbot+881d65229ca4f9ae8c84@syzkaller.appspotmail.com>
Closes: https://syzkaller.appspot.com/bug?extid=881d65229ca4f9ae8c84
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: Oleksij Rempel <o.rempel@pengutronix.de>
Link: https://patch.msgid.link/b9653191-d479-4c8b-8536-1326d028db5c@I-love.SAKURA.ne.jp
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-17 16:35:33 +01:00
Florian Westphal
09d6074995 netfilter: nf_tables: avoid chain re-validation if possible
[ Upstream commit 8e1a1bc4f5 ]

Hamza Mahfooz reports cpu soft lock-ups in
nft_chain_validate():

 watchdog: BUG: soft lockup - CPU#1 stuck for 27s! [iptables-nft-re:37547]
[..]
 RIP: 0010:nft_chain_validate+0xcb/0x110 [nf_tables]
[..]
  nft_immediate_validate+0x36/0x50 [nf_tables]
  nft_chain_validate+0xc9/0x110 [nf_tables]
  nft_immediate_validate+0x36/0x50 [nf_tables]
  nft_chain_validate+0xc9/0x110 [nf_tables]
  nft_immediate_validate+0x36/0x50 [nf_tables]
  nft_chain_validate+0xc9/0x110 [nf_tables]
  nft_immediate_validate+0x36/0x50 [nf_tables]
  nft_chain_validate+0xc9/0x110 [nf_tables]
  nft_immediate_validate+0x36/0x50 [nf_tables]
  nft_chain_validate+0xc9/0x110 [nf_tables]
  nft_immediate_validate+0x36/0x50 [nf_tables]
  nft_chain_validate+0xc9/0x110 [nf_tables]
  nft_table_validate+0x6b/0xb0 [nf_tables]
  nf_tables_validate+0x8b/0xa0 [nf_tables]
  nf_tables_commit+0x1df/0x1eb0 [nf_tables]
[..]

Currently nf_tables will traverse the entire table (chain graph), starting
from the entry points (base chains), exploring all possible paths
(chain jumps).  But there are cases where we could avoid revalidation.

Consider:
1  input -> j2 -> j3
2  input -> j2 -> j3
3  input -> j1 -> j2 -> j3

Then the second rule does not need to revalidate j2, and, by extension j3,
because this was already checked during validation of the first rule.
We need to validate it only for rule 3.

This is needed because chain loop detection also ensures we do not exceed
the jump stack: Just because we know that j2 is cycle free, its last jump
might now exceed the allowed stack size.  We also need to update all
reachable chains with the new largest observed call depth.

Care has to be taken to revalidate even if the chain depth won't be an
issue: chain validation also ensures that expressions are not called from
invalid base chains.  For example, the masquerade expression can only be
called from NAT postrouting base chains.

Therefore we also need to keep record of the base chain context (type,
hooknum) and revalidate if the chain becomes reachable from a different
hook location.

Reported-by: Hamza Mahfooz <hamzamahfooz@linux.microsoft.com>
Closes: https://lore.kernel.org/netfilter-devel/20251118221735.GA5477@linuxonhyperv3.guj3yctzbm1etfxqx2vob5hsef.xx.internal.cloudapp.net/
Tested-by: Hamza Mahfooz <hamzamahfooz@linux.microsoft.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-17 16:35:32 +01:00
Tetsuo Handa
737be05a76 bpf: Fix reference count leak in bpf_prog_test_run_xdp()
[ Upstream commit ec69daabe4 ]

syzbot is reporting

  unregister_netdevice: waiting for sit0 to become free. Usage count = 2

problem. A debug printk() patch found that a refcount is obtained at
xdp_convert_md_to_buff() from bpf_prog_test_run_xdp().

According to commit ec94670fcb ("bpf: Support specifying ingress via
xdp_md context in BPF_PROG_TEST_RUN"), the refcount obtained by
xdp_convert_md_to_buff() will be released by xdp_convert_buff_to_md().

Therefore, we can consider that the error handling path introduced by
commit 1c19499825 ("bpf: introduce frags support to
bpf_prog_test_run_xdp()") forgot to call xdp_convert_buff_to_md().

Reported-by: syzbot+881d65229ca4f9ae8c84@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=881d65229ca4f9ae8c84
Fixes: 1c19499825 ("bpf: introduce frags support to bpf_prog_test_run_xdp()")
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/r/af090e53-9d9b-4412-8acb-957733b3975c@I-love.SAKURA.ne.jp
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-17 16:35:31 +01:00
Toke Høiland-Jørgensen
31e37f44b6 bpf, test_run: Subtract size of xdp_frame from allowed metadata size
[ Upstream commit e558cca217 ]

The xdp_frame structure takes up part of the XDP frame headroom,
limiting the size of the metadata. However, in bpf_test_run, we don't
take this into account, which makes it possible for userspace to supply
a metadata size that is too large (taking up the entire headroom).

If userspace supplies such a large metadata size in live packet mode,
the xdp_update_frame_from_buff() call in xdp_test_run_init_page() call
will fail, after which packet transmission proceeds with an
uninitialised frame structure, leading to the usual Bad Stuff.

The commit in the Fixes tag fixed a related bug where the second check
in xdp_update_frame_from_buff() could fail, but did not add any
additional constraints on the metadata size. Complete the fix by adding
an additional check on the metadata size. Reorder the checks slightly to
make the logic clearer and add a comment.

Link: https://lore.kernel.org/r/fa2be179-bad7-4ee3-8668-4903d1853461@hust.edu.cn
Fixes: b6f1f780b3 ("bpf, test_run: Fix packet size check for live packet mode")
Reported-by: Yinhao Hu <dddddd@hust.edu.cn>
Reported-by: Kaiyan Mei <M202472210@hust.edu.cn>
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Reviewed-by: Amery Hung <ameryhung@gmail.com>
Link: https://lore.kernel.org/r/20260105114747.1358750-1-toke@redhat.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-17 16:35:31 +01:00
Eric Dumazet
949647e777 arp: do not assume dev_hard_header() does not change skb->head
[ Upstream commit c92510f5e3 ]

arp_create() is the only dev_hard_header() caller
making assumption about skb->head being unchanged.

A recent commit broke this assumption.

Initialize @arp pointer after dev_hard_header() call.

Fixes: db5b4e39c4 ("ip6_gre: make ip6gre_header() robust")
Reported-by: syzbot+58b44a770a1585795351@syzkaller.appspotmail.com
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260107212250.384552-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-17 16:35:30 +01:00
Xiang Mei
51ffd447bc net/sched: sch_qfq: Fix NULL deref when deactivating inactive aggregate in qfq_reset
[ Upstream commit c1d73b1480 ]

`qfq_class->leaf_qdisc->q.qlen > 0` does not imply that the class
itself is active.

Two qfq_class objects may point to the same leaf_qdisc. This happens
when:

1. one QFQ qdisc is attached to the dev as the root qdisc, and

2. another QFQ qdisc is temporarily referenced (e.g., via qdisc_get()
/ qdisc_put()) and is pending to be destroyed, as in function
tc_new_tfilter.

When packets are enqueued through the root QFQ qdisc, the shared
leaf_qdisc->q.qlen increases. At the same time, the second QFQ
qdisc triggers qdisc_put and qdisc_destroy: the qdisc enters
qfq_reset() with its own q->q.qlen == 0, but its class's leaf
qdisc->q.qlen > 0. Therefore, the qfq_reset would wrongly deactivate
an inactive aggregate and trigger a null-deref in qfq_deactivate_agg:

[    0.903172] BUG: kernel NULL pointer dereference, address: 0000000000000000
[    0.903571] #PF: supervisor write access in kernel mode
[    0.903860] #PF: error_code(0x0002) - not-present page
[    0.904177] PGD 10299b067 P4D 10299b067 PUD 10299c067 PMD 0
[    0.904502] Oops: Oops: 0002 [#1] SMP NOPTI
[    0.904737] CPU: 0 UID: 0 PID: 135 Comm: exploit Not tainted 6.19.0-rc3+ #2 NONE
[    0.905157] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.17.0-0-gb52ca86e094d-prebuilt.qemu.org 04/01/2014
[    0.905754] RIP: 0010:qfq_deactivate_agg (include/linux/list.h:992 (discriminator 2) include/linux/list.h:1006 (discriminator 2) net/sched/sch_qfq.c:1367 (discriminator 2) net/sched/sch_qfq.c:1393 (discriminator 2))
[    0.906046] Code: 0f 84 4d 01 00 00 48 89 70 18 8b 4b 10 48 c7 c2 ff ff ff ff 48 8b 78 08 48 d3 e2 48 21 f2 48 2b 13 48 8b 30 48 d3 ea 8b 4b 18 0

Code starting with the faulting instruction
===========================================
   0:	0f 84 4d 01 00 00    	je     0x153
   6:	48 89 70 18          	mov    %rsi,0x18(%rax)
   a:	8b 4b 10             	mov    0x10(%rbx),%ecx
   d:	48 c7 c2 ff ff ff ff 	mov    $0xffffffffffffffff,%rdx
  14:	48 8b 78 08          	mov    0x8(%rax),%rdi
  18:	48 d3 e2             	shl    %cl,%rdx
  1b:	48 21 f2             	and    %rsi,%rdx
  1e:	48 2b 13             	sub    (%rbx),%rdx
  21:	48 8b 30             	mov    (%rax),%rsi
  24:	48 d3 ea             	shr    %cl,%rdx
  27:	8b 4b 18             	mov    0x18(%rbx),%ecx
	...
[    0.907095] RSP: 0018:ffffc900004a39a0 EFLAGS: 00010246
[    0.907368] RAX: ffff8881043a0880 RBX: ffff888102953340 RCX: 0000000000000000
[    0.907723] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
[    0.908100] RBP: ffff888102952180 R08: 0000000000000000 R09: 0000000000000000
[    0.908451] R10: ffff8881043a0000 R11: 0000000000000000 R12: ffff888102952000
[    0.908804] R13: ffff888102952180 R14: ffff8881043a0ad8 R15: ffff8881043a0880
[    0.909179] FS:  000000002a1a0380(0000) GS:ffff888196d8d000(0000) knlGS:0000000000000000
[    0.909572] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    0.909857] CR2: 0000000000000000 CR3: 0000000102993002 CR4: 0000000000772ef0
[    0.910247] PKRU: 55555554
[    0.910391] Call Trace:
[    0.910527]  <TASK>
[    0.910638]  qfq_reset_qdisc (net/sched/sch_qfq.c:357 net/sched/sch_qfq.c:1485)
[    0.910826]  qdisc_reset (include/linux/skbuff.h:2195 include/linux/skbuff.h:2501 include/linux/skbuff.h:3424 include/linux/skbuff.h:3430 net/sched/sch_generic.c:1036)
[    0.911040]  __qdisc_destroy (net/sched/sch_generic.c:1076)
[    0.911236]  tc_new_tfilter (net/sched/cls_api.c:2447)
[    0.911447]  rtnetlink_rcv_msg (net/core/rtnetlink.c:6958)
[    0.911663]  ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6861)
[    0.911894]  netlink_rcv_skb (net/netlink/af_netlink.c:2550)
[    0.912100]  netlink_unicast (net/netlink/af_netlink.c:1319 net/netlink/af_netlink.c:1344)
[    0.912296]  ? __alloc_skb (net/core/skbuff.c:706)
[    0.912484]  netlink_sendmsg (net/netlink/af_netlink.c:1894)
[    0.912682]  sock_write_iter (net/socket.c:727 (discriminator 1) net/socket.c:742 (discriminator 1) net/socket.c:1195 (discriminator 1))
[    0.912880]  vfs_write (fs/read_write.c:593 fs/read_write.c:686)
[    0.913077]  ksys_write (fs/read_write.c:738)
[    0.913252]  do_syscall_64 (arch/x86/entry/syscall_64.c:63 (discriminator 1) arch/x86/entry/syscall_64.c:94 (discriminator 1))
[    0.913438]  entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:131)
[    0.913687] RIP: 0033:0x424c34
[    0.913844] Code: 89 02 48 c7 c0 ff ff ff ff eb bd 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 80 3d 2d 44 09 00 00 74 13 b8 01 00 00 00 0f 05 9

Code starting with the faulting instruction
===========================================
   0:	89 02                	mov    %eax,(%rdx)
   2:	48 c7 c0 ff ff ff ff 	mov    $0xffffffffffffffff,%rax
   9:	eb bd                	jmp    0xffffffffffffffc8
   b:	66 2e 0f 1f 84 00 00 	cs nopw 0x0(%rax,%rax,1)
  12:	00 00 00
  15:	90                   	nop
  16:	f3 0f 1e fa          	endbr64
  1a:	80 3d 2d 44 09 00 00 	cmpb   $0x0,0x9442d(%rip)        # 0x9444e
  21:	74 13                	je     0x36
  23:	b8 01 00 00 00       	mov    $0x1,%eax
  28:	0f 05                	syscall
  2a:	09                   	.byte 0x9
[    0.914807] RSP: 002b:00007ffea1938b78 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
[    0.915197] RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 0000000000424c34
[    0.915556] RDX: 000000000000003c RSI: 000000002af378c0 RDI: 0000000000000003
[    0.915912] RBP: 00007ffea1938bc0 R08: 00000000004b8820 R09: 0000000000000000
[    0.916297] R10: 0000000000000001 R11: 0000000000000202 R12: 00007ffea1938d28
[    0.916652] R13: 00007ffea1938d38 R14: 00000000004b3828 R15: 0000000000000001
[    0.917039]  </TASK>
[    0.917158] Modules linked in:
[    0.917316] CR2: 0000000000000000
[    0.917484] ---[ end trace 0000000000000000 ]---
[    0.917717] RIP: 0010:qfq_deactivate_agg (include/linux/list.h:992 (discriminator 2) include/linux/list.h:1006 (discriminator 2) net/sched/sch_qfq.c:1367 (discriminator 2) net/sched/sch_qfq.c:1393 (discriminator 2))
[    0.917978] Code: 0f 84 4d 01 00 00 48 89 70 18 8b 4b 10 48 c7 c2 ff ff ff ff 48 8b 78 08 48 d3 e2 48 21 f2 48 2b 13 48 8b 30 48 d3 ea 8b 4b 18 0

Code starting with the faulting instruction
===========================================
   0:	0f 84 4d 01 00 00    	je     0x153
   6:	48 89 70 18          	mov    %rsi,0x18(%rax)
   a:	8b 4b 10             	mov    0x10(%rbx),%ecx
   d:	48 c7 c2 ff ff ff ff 	mov    $0xffffffffffffffff,%rdx
  14:	48 8b 78 08          	mov    0x8(%rax),%rdi
  18:	48 d3 e2             	shl    %cl,%rdx
  1b:	48 21 f2             	and    %rsi,%rdx
  1e:	48 2b 13             	sub    (%rbx),%rdx
  21:	48 8b 30             	mov    (%rax),%rsi
  24:	48 d3 ea             	shr    %cl,%rdx
  27:	8b 4b 18             	mov    0x18(%rbx),%ecx
	...
[    0.918902] RSP: 0018:ffffc900004a39a0 EFLAGS: 00010246
[    0.919198] RAX: ffff8881043a0880 RBX: ffff888102953340 RCX: 0000000000000000
[    0.919559] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
[    0.919908] RBP: ffff888102952180 R08: 0000000000000000 R09: 0000000000000000
[    0.920289] R10: ffff8881043a0000 R11: 0000000000000000 R12: ffff888102952000
[    0.920648] R13: ffff888102952180 R14: ffff8881043a0ad8 R15: ffff8881043a0880
[    0.921014] FS:  000000002a1a0380(0000) GS:ffff888196d8d000(0000) knlGS:0000000000000000
[    0.921424] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    0.921710] CR2: 0000000000000000 CR3: 0000000102993002 CR4: 0000000000772ef0
[    0.922097] PKRU: 55555554
[    0.922240] Kernel panic - not syncing: Fatal exception
[    0.922590] Kernel Offset: disabled

Fixes: 0545a30377 ("pkt_sched: QFQ - quick fair queue scheduler")
Signed-off-by: Xiang Mei <xmei5@asu.edu>
Link: https://patch.msgid.link/20260106034100.1780779-1-xmei5@asu.edu
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-17 16:35:29 +01:00
Shivani Gupta
67550a1130 net/sched: act_api: avoid dereferencing ERR_PTR in tcf_idrinfo_destroy
[ Upstream commit adb25a46dc ]

syzbot reported a crash in tc_act_in_hw() during netns teardown where
tcf_idrinfo_destroy() passed an ERR_PTR(-EBUSY) value as a tc_action
pointer, leading to an invalid dereference.

Guard against ERR_PTR entries when iterating the action IDR so teardown
does not call tc_act_in_hw() on an error pointer.

Fixes: 84a7d6797e ("net/sched: acp_api: no longer acquire RTNL in tc_action_net_exit()")
Link: https://syzkaller.appspot.com/bug?extid=8f1c492ffa4644ff3826
Reported-by: syzbot+8f1c492ffa4644ff3826@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=8f1c492ffa4644ff3826
Signed-off-by: Shivani Gupta <shivani07g@gmail.com>
Link: https://patch.msgid.link/20260105005905.243423-1-shivani07g@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-17 16:35:28 +01:00
Eric Dumazet
0c63d5683e udp: call skb_orphan() before skb_attempt_defer_free()
[ Upstream commit e5c8eda39a ]

Standard UDP receive path does not use skb->destructor.

But skmsg layer does use it, since it calls skb_set_owner_sk_safe()
from udp_read_skb().

This then triggers this warning in skb_attempt_defer_free():

    DEBUG_NET_WARN_ON_ONCE(skb->destructor);

We must call skb_orphan() to fix this issue.

Fixes: 6471658dc6 ("udp: use skb_attempt_defer_free()")
Reported-by: syzbot+3e68572cf2286ce5ebe9@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/695b83bd.050a0220.1c9965.002b.GAE@google.com/T/#u
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260105093630.1976085-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-17 16:35:28 +01:00
Mohammad Heib
c114a32a2e net: fix memory leak in skb_segment_list for GRO packets
[ Upstream commit 238e03d046 ]

When skb_segment_list() is called during packet forwarding, it handles
packets that were aggregated by the GRO engine.

Historically, the segmentation logic in skb_segment_list assumes that
individual segments are split from a parent SKB and may need to carry
their own socket memory accounting. Accordingly, the code transfers
truesize from the parent to the newly created segments.

Prior to commit ed4cccef64 ("gro: fix ownership transfer"), this
truesize subtraction in skb_segment_list() was valid because fragments
still carry a reference to the original socket.

However, commit ed4cccef64 ("gro: fix ownership transfer") changed
this behavior by ensuring that fraglist entries are explicitly
orphaned (skb->sk = NULL) to prevent illegal orphaning later in the
stack. This change meant that the entire socket memory charge remained
with the head SKB, but the corresponding accounting logic in
skb_segment_list() was never updated.

As a result, the current code unconditionally adds each fragment's
truesize to delta_truesize and subtracts it from the parent SKB. Since
the fragments are no longer charged to the socket, this subtraction
results in an effective under-count of memory when the head is freed.
This causes sk_wmem_alloc to remain non-zero, preventing socket
destruction and leading to a persistent memory leak.

The leak can be observed via KMEMLEAK when tearing down the networking
environment:

unreferenced object 0xffff8881e6eb9100 (size 2048):
  comm "ping", pid 6720, jiffies 4295492526
  backtrace:
    kmem_cache_alloc_noprof+0x5c6/0x800
    sk_prot_alloc+0x5b/0x220
    sk_alloc+0x35/0xa00
    inet6_create.part.0+0x303/0x10d0
    __sock_create+0x248/0x640
    __sys_socket+0x11b/0x1d0

Since skb_segment_list() is exclusively used for SKB_GSO_FRAGLIST
packets constructed by GRO, the truesize adjustment is removed.

The call to skb_release_head_state() must be preserved. As documented in
commit cf673ed0e0 ("net: fix fraglist segmentation reference count
leak"), it is still required to correctly drop references to SKB
extensions that may be overwritten during __copy_skb_header().

Fixes: ed4cccef64 ("gro: fix ownership transfer")
Signed-off-by: Mohammad Heib <mheib@redhat.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20260104213101.352887-1-mheib@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-17 16:35:26 +01:00
Michal Luczaj
0185dc4b5b vsock: Make accept()ed sockets use custom setsockopt()
[ Upstream commit ce5e612dd4 ]

SO_ZEROCOPY handling in vsock_connectible_setsockopt() does not get called
on accept()ed sockets due to a missing flag. Flip it.

Fixes: e0718bd82e ("vsock: enable setting SO_ZEROCOPY")
Signed-off-by: Michal Luczaj <mhal@rbox.co>
Link: https://patch.msgid.link/20251229-vsock-child-sock-custom-sockopt-v2-1-64778d6c4f88@rbox.co
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-17 16:35:25 +01:00
Florian Westphal
088ca99dbb inet: frags: drop fraglist conntrack references
[ Upstream commit 2ef02ac38d ]

Jakub added a warning in nf_conntrack_cleanup_net_list() to make debugging
leaked skbs/conntrack references more obvious.

syzbot reports this as triggering, and I can also reproduce this via
ip_defrag.sh selftest:

 conntrack cleanup blocked for 60s
 WARNING: net/netfilter/nf_conntrack_core.c:2512
 [..]

conntrack clenups gets stuck because there are skbs with still hold nf_conn
references via their frag_list.

   net.core.skb_defer_max=0 makes the hang disappear.

Eric Dumazet points out that skb_release_head_state() doesn't follow the
fraglist.

ip_defrag.sh can only reproduce this problem since
commit 6471658dc6 ("udp: use skb_attempt_defer_free()"), but AFAICS this
problem could happen with TCP as well if pmtu discovery is off.

The relevant problem path for udp is:
1. netns emits fragmented packets
2. nf_defrag_v6_hook reassembles them (in output hook)
3. reassembled skb is tracked (skb owns nf_conn reference)
4. ip6_output refragments
5. refragmented packets also own nf_conn reference (ip6_fragment
   calls ip6_copy_metadata())
6. on input path, nf_defrag_v6_hook skips defragmentation: the
   fragments already have skb->nf_conn attached
7. skbs are reassembled via ipv6_frag_rcv()
8. skb_consume_udp -> skb_attempt_defer_free() -> skb ends up
   in pcpu freelist, but still has nf_conn reference.

Possible solutions:
 1 let defrag engine drop nf_conn entry, OR
 2 export kick_defer_list_purge() and call it from the conntrack
   netns exit callback, OR
 3 add skb_has_frag_list() check to skb_attempt_defer_free()

2 & 3 also solve ip_defrag.sh hang but share same drawback:

Such reassembled skbs, queued to socket, can prevent conntrack module
removal until userspace has consumed the packet. While both tcp and udp
stack do call nf_reset_ct() before placing skb on socket queue, that
function doesn't iterate frag_list skbs.

Therefore drop nf_conn entries when they are placed in defrag queue.
Keep the nf_conn entry of the first (offset 0) skb so that reassembled
skb retains nf_conn entry for sake of TX path.

Note that fixes tag is incorrect; it points to the commit introducing the
'ip_defrag.sh reproducible problem': no need to backport this patch to
every stable kernel.

Reported-by: syzbot+4393c47753b7808dac7d@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/693b0fa7.050a0220.4004e.040d.GAE@google.com/
Fixes: 6471658dc6 ("udp: use skb_attempt_defer_free()")
Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260102140030.32367-1-fw@strlen.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-17 16:35:24 +01:00
Weiming Shi
e00b169eaa net: sock: fix hardened usercopy panic in sock_recv_errqueue
[ Upstream commit 2a71a1a8d0 ]

skbuff_fclone_cache was created without defining a usercopy region,
[1] unlike skbuff_head_cache which properly whitelists the cb[] field.
[2] This causes a usercopy BUG() when CONFIG_HARDENED_USERCOPY is
enabled and the kernel attempts to copy sk_buff.cb data to userspace
via sock_recv_errqueue() -> put_cmsg().

The crash occurs when: 1. TCP allocates an skb using alloc_skb_fclone()
   (from skbuff_fclone_cache) [1]
2. The skb is cloned via skb_clone() using the pre-allocated fclone
[3] 3. The cloned skb is queued to sk_error_queue for timestamp
reporting 4. Userspace reads the error queue via recvmsg(MSG_ERRQUEUE)
5. sock_recv_errqueue() calls put_cmsg() to copy serr->ee from skb->cb
[4] 6. __check_heap_object() fails because skbuff_fclone_cache has no
   usercopy whitelist [5]

When cloned skbs allocated from skbuff_fclone_cache are used in the
socket error queue, accessing the sock_exterr_skb structure in skb->cb
via put_cmsg() triggers a usercopy hardening violation:

[    5.379589] usercopy: Kernel memory exposure attempt detected from SLUB object 'skbuff_fclone_cache' (offset 296, size 16)!
[    5.382796] kernel BUG at mm/usercopy.c:102!
[    5.383923] Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
[    5.384903] CPU: 1 UID: 0 PID: 138 Comm: poc_put_cmsg Not tainted 6.12.57 #7
[    5.384903] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[    5.384903] RIP: 0010:usercopy_abort+0x6c/0x80
[    5.384903] Code: 1a 86 51 48 c7 c2 40 15 1a 86 41 52 48 c7 c7 c0 15 1a 86 48 0f 45 d6 48 c7 c6 80 15 1a 86 48 89 c1 49 0f 45 f3 e8 84 27 88 ff <0f> 0b 490
[    5.384903] RSP: 0018:ffffc900006f77a8 EFLAGS: 00010246
[    5.384903] RAX: 000000000000006f RBX: ffff88800f0ad2a8 RCX: 1ffffffff0f72e74
[    5.384903] RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffffff87b973a0
[    5.384903] RBP: 0000000000000010 R08: 0000000000000000 R09: fffffbfff0f72e74
[    5.384903] R10: 0000000000000003 R11: 79706f6372657375 R12: 0000000000000001
[    5.384903] R13: ffff88800f0ad2b8 R14: ffffea00003c2b40 R15: ffffea00003c2b00
[    5.384903] FS:  0000000011bc4380(0000) GS:ffff8880bf100000(0000) knlGS:0000000000000000
[    5.384903] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    5.384903] CR2: 000056aa3b8e5fe4 CR3: 000000000ea26004 CR4: 0000000000770ef0
[    5.384903] PKRU: 55555554
[    5.384903] Call Trace:
[    5.384903]  <TASK>
[    5.384903]  __check_heap_object+0x9a/0xd0
[    5.384903]  __check_object_size+0x46c/0x690
[    5.384903]  put_cmsg+0x129/0x5e0
[    5.384903]  sock_recv_errqueue+0x22f/0x380
[    5.384903]  tls_sw_recvmsg+0x7ed/0x1960
[    5.384903]  ? srso_alias_return_thunk+0x5/0xfbef5
[    5.384903]  ? schedule+0x6d/0x270
[    5.384903]  ? srso_alias_return_thunk+0x5/0xfbef5
[    5.384903]  ? mutex_unlock+0x81/0xd0
[    5.384903]  ? __pfx_mutex_unlock+0x10/0x10
[    5.384903]  ? __pfx_tls_sw_recvmsg+0x10/0x10
[    5.384903]  ? _raw_spin_lock_irqsave+0x8f/0xf0
[    5.384903]  ? _raw_read_unlock_irqrestore+0x20/0x40
[    5.384903]  ? srso_alias_return_thunk+0x5/0xfbef5

The crash offset 296 corresponds to skb2->cb within skbuff_fclones:
  - sizeof(struct sk_buff) = 232 - offsetof(struct sk_buff, cb) = 40 -
  offset of skb2.cb in fclones = 232 + 40 = 272 - crash offset 296 =
  272 + 24 (inside sock_exterr_skb.ee)

This patch uses a local stack variable as a bounce buffer to avoid the hardened usercopy check failure.

[1] https://elixir.bootlin.com/linux/v6.12.62/source/net/ipv4/tcp.c#L885
[2] https://elixir.bootlin.com/linux/v6.12.62/source/net/core/skbuff.c#L5104
[3] https://elixir.bootlin.com/linux/v6.12.62/source/net/core/skbuff.c#L5566
[4] https://elixir.bootlin.com/linux/v6.12.62/source/net/core/skbuff.c#L5491
[5] https://elixir.bootlin.com/linux/v6.12.62/source/mm/slub.c#L5719

Fixes: 6d07d1cd30 ("usercopy: Restrict non-usercopy caches to size 0")
Reported-by: Xiang Mei <xmei5@asu.edu>
Signed-off-by: Weiming Shi <bestswngs@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20251223203534.1392218-2-bestswngs@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-17 16:35:23 +01:00
yuan.gao
1511ba2d68 inet: ping: Fix icmp out counting
[ Upstream commit 4c0856c225 ]

When the ping program uses an IPPROTO_ICMP socket to send ICMP_ECHO
messages, ICMP_MIB_OUTMSGS is counted twice.

    ping_v4_sendmsg
      ping_v4_push_pending_frames
        ip_push_pending_frames
          ip_finish_skb
            __ip_make_skb
              icmp_out_count(net, icmp_type); // first count
      icmp_out_count(sock_net(sk), user_icmph.type); // second count

However, when the ping program uses an IPPROTO_RAW socket,
ICMP_MIB_OUTMSGS is counted correctly only once.

Therefore, the first count should be removed.

Fixes: c319b4d76b ("net: ipv4: add IPPROTO_ICMP socket kind")
Signed-off-by: yuan.gao <yuan.gao@ucloud.cn>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Tested-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20251224063145.3615282-1-yuan.gao@ucloud.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-17 16:35:22 +01:00
Alexandre Knecht
b53fca69f4 bridge: fix C-VLAN preservation in 802.1ad vlan_tunnel egress
[ Upstream commit 3128df6be1 ]

When using an 802.1ad bridge with vlan_tunnel, the C-VLAN tag is
incorrectly stripped from frames during egress processing.

br_handle_egress_vlan_tunnel() uses skb_vlan_pop() to remove the S-VLAN
from hwaccel before VXLAN encapsulation. However, skb_vlan_pop() also
moves any "next" VLAN from the payload into hwaccel:

    /* move next vlan tag to hw accel tag */
    __skb_vlan_pop(skb, &vlan_tci);
    __vlan_hwaccel_put_tag(skb, vlan_proto, vlan_tci);

For QinQ frames where the C-VLAN sits in the payload, this moves it to
hwaccel where it gets lost during VXLAN encapsulation.

Fix by calling __vlan_hwaccel_clear_tag() directly, which clears only
the hwaccel S-VLAN and leaves the payload untouched.

This path is only taken when vlan_tunnel is enabled and tunnel_info
is configured, so 802.1Q bridges are unaffected.

Tested with 802.1ad bridge + VXLAN vlan_tunnel, verified C-VLAN
preserved in VXLAN payload via tcpdump.

Fixes: 11538d039a ("bridge: vlan dst_metadata hooks in ingress and egress paths")
Signed-off-by: Alexandre Knecht <knecht.alexandre@gmail.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://patch.msgid.link/20251228020057.2788865-1-knecht.alexandre@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-17 16:35:22 +01:00
Fernando Fernandez Mancera
8bdafdf490 netfilter: nf_conncount: update last_gc only when GC has been performed
[ Upstream commit 7811ba4524 ]

Currently last_gc is being updated everytime a new connection is
tracked, that means that it is updated even if a GC wasn't performed.
With a sufficiently high packet rate, it is possible to always bypass
the GC, causing the list to grow infinitely.

Update the last_gc value only when a GC has been actually performed.

Fixes: d265929930 ("netfilter: nf_conncount: reduce unnecessary GC")
Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-17 16:35:22 +01:00
Zilin Guan
7f066cba65 netfilter: nf_tables: fix memory leak in nf_tables_newrule()
[ Upstream commit d077e8119d ]

In nf_tables_newrule(), if nft_use_inc() fails, the function jumps to
the err_release_rule label without freeing the allocated flow, leading
to a memory leak.

Fix this by adding a new label err_destroy_flow and jumping to it when
nft_use_inc() fails. This ensures that the flow is properly released
in this error case.

Fixes: 1689f25924 ("netfilter: nf_tables: report use refcount overflow")
Signed-off-by: Zilin Guan <zilin@seu.edu.cn>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-17 16:35:22 +01:00
Fernando Fernandez Mancera
75bfb05067 netfilter: nft_synproxy: avoid possible data-race on update operation
[ Upstream commit 36a3200575 ]

During nft_synproxy eval we are reading nf_synproxy_info struct which
can be modified on update operation concurrently. As nf_synproxy_info
struct fits in 32 bits, use READ_ONCE/WRITE_ONCE annotations.

Fixes: ee394f96ad ("netfilter: nft_synproxy: add synproxy stateful object support")
Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-17 16:35:21 +01:00
Florian Westphal
704c0258f0 netfilter: nft_set_pipapo: fix range overlap detection
[ Upstream commit 7711f4bb4b ]

set->klen has to be used, not sizeof().  The latter only compares a
single register but a full check of the entire key is needed.

Example:
table ip t {
        map s {
                typeof iifname . ip saddr : verdict
                flags interval
        }
}

nft add element t s '{ "lo" . 10.0.0.0/24 : drop }' # no error, expected
nft add element t s '{ "lo" . 10.0.0.0/24 : drop }' # no error, expected
nft add element t s '{ "lo" . 10.0.0.0/8 : drop }' # bug: no error

The 3rd 'add element' should be rejected via -ENOTEMPTY, not -EEXIST,
so userspace / nft can report an error to the user.

The latter is only correct for the 2nd case (re-add of existing element).

As-is, userspace is told that the command was successful, but no elements were
added.

After this patch, 3rd command gives:
Error: Could not process rule: File exists
add element t s { "lo" . 127.0.0.0/8 . "lo"  : drop }
                  ^^^^^^^^^^^^^^^^^^^^^^^^^

Fixes: 0eb4b5ee33 ("netfilter: nft_set_pipapo: Separate partial and complete overlap cases on insertion")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-17 16:35:21 +01:00
Ilya Dryomov
5647d42c47 libceph: make calc_target() set t->paused, not just clear it
commit c0fe2994f9 upstream.

Currently calc_target() clears t->paused if the request shouldn't be
paused anymore, but doesn't ever set t->paused even though it's able to
determine when the request should be paused.  Setting t->paused is left
to __submit_request() which is fine for regular requests but doesn't
work for linger requests -- since __submit_request() doesn't operate
on linger requests, there is nowhere for lreq->t.paused to be set.
One consequence of this is that watches don't get reestablished on
paused -> unpaused transitions in cases where requests have been paused
long enough for the (paused) unwatch request to time out and for the
subsequent (re)watch request to enter the paused state.  On top of the
watch not getting reestablished, rbd_reregister_watch() gets stuck with
rbd_dev->watch_mutex held:

  rbd_register_watch
    __rbd_register_watch
      ceph_osdc_watch
        linger_reg_commit_wait

It's waiting for lreq->reg_commit_wait to be completed, but for that to
happen the respective request needs to end up on need_resend_linger list
and be kicked when requests are unpaused.  There is no chance for that
if the request in question is never marked paused in the first place.

The fact that rbd_dev->watch_mutex remains taken out forever then
prevents the image from getting unmapped -- "rbd unmap" would inevitably
hang in D state on an attempt to grab the mutex.

Cc: stable@vger.kernel.org
Reported-by: Raphael Zimmer <raphael.zimmer@tu-ilmenau.de>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Viacheslav Dubeyko <Slava.Dubeyko@ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-01-17 16:35:15 +01:00
Sam Edwards
10b7c72810 libceph: reset sparse-read state in osd_fault()
commit 11194b416e upstream.

When a fault occurs, the connection is abandoned, reestablished, and any
pending operations are retried. The OSD client tracks the progress of a
sparse-read reply using a separate state machine, largely independent of
the messenger's state.

If a connection is lost mid-payload or the sparse-read state machine
returns an error, the sparse-read state is not reset. The OSD client
will then interpret the beginning of a new reply as the continuation of
the old one. If this makes the sparse-read machinery enter a failure
state, it may never recover, producing loops like:

  libceph:  [0] got 0 extents
  libceph: data len 142248331 != extent len 0
  libceph: osd0 (1)...:6801 socket error on read
  libceph: data len 142248331 != extent len 0
  libceph: osd0 (1)...:6801 socket error on read

Therefore, reset the sparse-read state in osd_fault(), ensuring retries
start from a clean state.

Cc: stable@vger.kernel.org
Fixes: f628d79997 ("libceph: add sparse read support to OSD client")
Signed-off-by: Sam Edwards <CFSworks@gmail.com>
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-01-17 16:35:15 +01:00
Ilya Dryomov
9e0101e575 libceph: return the handler error from mon_handle_auth_done()
commit e84b48d31b upstream.

Currently any error from ceph_auth_handle_reply_done() is propagated
via finish_auth() but isn't returned from mon_handle_auth_done().  This
results in higher layers learning that (despite the monitor considering
us to be successfully authenticated) something went wrong in the
authentication phase and reacting accordingly, but msgr2 still trying
to proceed with establishing the session in the background.  In the
case of secure mode this can trigger a WARN in setup_crypto() and later
lead to a NULL pointer dereference inside of prepare_auth_signature().

Cc: stable@vger.kernel.org
Fixes: cd1a677cad ("libceph, ceph: implement msgr2.1 protocol (crc and secure modes)")
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Viacheslav Dubeyko <Slava.Dubeyko@ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-01-17 16:35:15 +01:00
Tuo Li
f21c3fdb96 libceph: make free_choose_arg_map() resilient to partial allocation
commit e3fe30e576 upstream.

free_choose_arg_map() may dereference a NULL pointer if its caller fails
after a partial allocation.

For example, in decode_choose_args(), if allocation of arg_map->args
fails, execution jumps to the fail label and free_choose_arg_map() is
called. Since arg_map->size is updated to a non-zero value before memory
allocation, free_choose_arg_map() will iterate over arg_map->args and
dereference a NULL pointer.

To prevent this potential NULL pointer dereference and make
free_choose_arg_map() more resilient, add checks for pointers before
iterating.

Cc: stable@vger.kernel.org
Co-authored-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Tuo Li <islituo@gmail.com>
Reviewed-by: Viacheslav Dubeyko <Slava.Dubeyko@ibm.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-01-17 16:35:15 +01:00
Ilya Dryomov
6348d70af8 libceph: replace overzealous BUG_ON in osdmap_apply_incremental()
commit e00c3f71b5 upstream.

If the osdmap is (maliciously) corrupted such that the incremental
osdmap epoch is different from what is expected, there is no need to
BUG.  Instead, just declare the incremental osdmap to be invalid.

Cc: stable@vger.kernel.org
Reported-by: ziming zhang <ezrakiez@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-01-17 16:35:15 +01:00
ziming zhang
2d653bb63d libceph: prevent potential out-of-bounds reads in handle_auth_done()
commit 818156caff upstream.

Perform an explicit bounds check on payload_len to avoid a possible
out-of-bounds access in the callout.

[ idryomov: changelog ]

Cc: stable@vger.kernel.org
Signed-off-by: ziming zhang <ezrakiez@gmail.com>
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-01-17 16:35:15 +01:00
Johannes Berg
b97be67dc0 wifi: mac80211: restore non-chanctx injection behaviour
commit d594cc6f2c upstream.

During the transition to use channel contexts throughout, the
ability to do injection while in monitor mode concurrent with
another interface was lost, since the (virtual) monitor won't
have a chanctx assigned in this scenario.

It's harder to fix drivers that actually transitioned to using
channel contexts themselves, such as mt76, but it's easy to do
those that are (still) just using the emulation. Do that.

Cc: stable@vger.kernel.org
Link: https://bugzilla.kernel.org/show_bug.cgi?id=218763
Reported-and-tested-by: Oscar Alfonso Diaz <oscar.alfonso.diaz@gmail.com>
Fixes: 0a44dfc070 ("wifi: mac80211: simplify non-chanctx drivers")
Link: https://patch.msgid.link/20251216105242.18366-2-johannes@sipsolutions.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-01-17 16:35:15 +01:00
Eric Dumazet
e3c3517710 wifi: avoid kernel-infoleak from struct iw_point
commit 21cbf883d0 upstream.

struct iw_point has a 32bit hole on 64bit arches.

struct iw_point {
  void __user   *pointer;       /* Pointer to the data  (in user space) */
  __u16         length;         /* number of fields or size in bytes */
  __u16         flags;          /* Optional params */
};

Make sure to zero the structure to avoid disclosing 32bits of kernel data
to user space.

Fixes: 87de87d5e4 ("wext: Dispatch and handle compat ioctls entirely in net/wireless/wext.c")
Reported-by: syzbot+bfc7323743ca6dbcc3d3@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/695f83f3.050a0220.1c677c.0392.GAE@google.com/T/#u
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260108101927.857582-1-edumazet@google.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-01-17 16:35:14 +01:00
Willem de Bruijn
ffa2be496e net: do not write to msg_get_inq in callee
commit 7d11e047ed upstream.

NULL pointer dereference fix.

msg_get_inq is an input field from caller to callee. Don't set it in
the callee, as the caller may not clear it on struct reuse.

This is a kernel-internal variant of msghdr only, and the only user
does reinitialize the field. So this is not critical for that reason.
But it is more robust to avoid the write, and slightly simpler code.
And it fixes a bug, see below.

Callers set msg_get_inq to request the input queue length to be
returned in msg_inq. This is equivalent to but independent from the
SO_INQ request to return that same info as a cmsg (tp->recvmsg_inq).
To reduce branching in the hot path the second also sets the msg_inq.
That is WAI.

This is a fix to commit 4d1442979e ("af_unix: don't post cmsg for
SO_INQ unless explicitly asked for"), which fixed the inverse.

Also avoid NULL pointer dereference in unix_stream_read_generic if
state->msg is NULL and msg->msg_get_inq is written. A NULL state->msg
can happen when splicing as of commit 2b514574f7 ("net: af_unix:
implement splice for stream af_unix sockets").

Also collapse two branches using a bitwise or.

Cc: stable@vger.kernel.org
Fixes: 4d1442979e ("af_unix: don't post cmsg for SO_INQ unless explicitly asked for")
Link: https://lore.kernel.org/netdev/willemdebruijn.kernel.24d8030f7a3de@gmail.com/
Signed-off-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260106150626.3944363-1-willemdebruijn.kernel@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-01-17 16:35:11 +01:00
Paolo Abeni
f1a77dfc3b mptcp: ensure context reset on disconnect()
[ Upstream commit 86730ac255 ]

After the blamed commit below, if the MPC subflow is already in TCP_CLOSE
status or has fallback to TCP at mptcp_disconnect() time,
mptcp_do_fastclose() skips setting the `send_fastclose flag` and the later
__mptcp_close_ssk() does not reset anymore the related subflow context.

Any later connection will be created with both the `request_mptcp` flag
and the msk-level fallback status off (it is unconditionally cleared at
MPTCP disconnect time), leading to a warning in subflow_data_ready():

  WARNING: CPU: 26 PID: 8996 at net/mptcp/subflow.c:1519 subflow_data_ready (net/mptcp/subflow.c:1519 (discriminator 13))
  Modules linked in:
  CPU: 26 UID: 0 PID: 8996 Comm: syz.22.39 Not tainted 6.18.0-rc7-05427-g11fc074f6c36 #1 PREEMPT(voluntary)
  Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
  RIP: 0010:subflow_data_ready (net/mptcp/subflow.c:1519 (discriminator 13))
  Code: 90 0f 0b 90 90 e9 04 fe ff ff e8 b7 1e f5 fe 89 ee bf 07 00 00 00 e8 db 19 f5 fe 83 fd 07 0f 84 35 ff ff ff e8 9d 1e f5 fe 90 <0f> 0b 90 e9 27 ff ff ff e8 8f 1e f5 fe 4c 89 e7 48 89 de e8 14 09
  RSP: 0018:ffffc9002646fb30 EFLAGS: 00010293
  RAX: 0000000000000000 RBX: ffff88813b218000 RCX: ffffffff825c8435
  RDX: ffff8881300b3580 RSI: ffffffff825c8443 RDI: 0000000000000005
  RBP: 000000000000000b R08: ffffffff825c8435 R09: 000000000000000b
  R10: 0000000000000005 R11: 0000000000000007 R12: ffff888131ac0000
  R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
  FS:  00007f88330af6c0(0000) GS:ffff888a93dd2000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00007f88330aefe8 CR3: 000000010ff59000 CR4: 0000000000350ef0
  Call Trace:
   <TASK>
   tcp_data_ready (net/ipv4/tcp_input.c:5356)
   tcp_data_queue (net/ipv4/tcp_input.c:5445)
   tcp_rcv_state_process (net/ipv4/tcp_input.c:7165)
   tcp_v4_do_rcv (net/ipv4/tcp_ipv4.c:1955)
   __release_sock (include/net/sock.h:1158 (discriminator 6) net/core/sock.c:3180 (discriminator 6))
   release_sock (net/core/sock.c:3737)
   mptcp_sendmsg (net/mptcp/protocol.c:1763 net/mptcp/protocol.c:1857)
   inet_sendmsg (net/ipv4/af_inet.c:853 (discriminator 7))
   __sys_sendto (net/socket.c:727 (discriminator 15) net/socket.c:742 (discriminator 15) net/socket.c:2244 (discriminator 15))
   __x64_sys_sendto (net/socket.c:2247)
   do_syscall_64 (arch/x86/entry/syscall_64.c:63 (discriminator 1) arch/x86/entry/syscall_64.c:94 (discriminator 1))
   entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
  RIP: 0033:0x7f883326702d

Address the issue setting an explicit `fastclosing` flag at fastclose
time, and checking such flag after mptcp_do_fastclose().

Fixes: ae15506024 ("mptcp: fix duplicate reset on fastclose")
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20251212-net-mptcp-subflow_data_ready-warn-v1-2-d1f9fd1c36c8@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
[ Adjust context ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-01-11 15:26:19 +01:00
Deepanshu Kartikey
f3a8a7c1aa net: nfc: fix deadlock between nfc_unregister_device and rfkill_fop_write
commit 1ab526d97a upstream.

A deadlock can occur between nfc_unregister_device() and rfkill_fop_write()
due to lock ordering inversion between device_lock and rfkill_global_mutex.

The problematic lock order is:

Thread A (rfkill_fop_write):
  rfkill_fop_write()
    mutex_lock(&rfkill_global_mutex)
      rfkill_set_block()
        nfc_rfkill_set_block()
          nfc_dev_down()
            device_lock(&dev->dev)    <- waits for device_lock

Thread B (nfc_unregister_device):
  nfc_unregister_device()
    device_lock(&dev->dev)
      rfkill_unregister()
        mutex_lock(&rfkill_global_mutex)  <- waits for rfkill_global_mutex

This creates a classic ABBA deadlock scenario.

Fix this by moving rfkill_unregister() and rfkill_destroy() outside the
device_lock critical section. Store the rfkill pointer in a local variable
before releasing the lock, then call rfkill_unregister() after releasing
device_lock.

This change is safe because rfkill_fop_write() holds rfkill_global_mutex
while calling the rfkill callbacks, and rfkill_unregister() also acquires
rfkill_global_mutex before cleanup. Therefore, rfkill_unregister() will
wait for any ongoing callback to complete before proceeding, and
device_del() is only called after rfkill_unregister() returns, preventing
any use-after-free.

The similar lock ordering in nfc_register_device() (device_lock ->
rfkill_global_mutex via rfkill_register) is safe because during
registration the device is not yet in rfkill_list, so no concurrent
rfkill operations can occur on this device.

Fixes: 3e3b5dfcd1 ("NFC: reorder the logic in nfc_{un,}register_device")
Cc: stable@vger.kernel.org
Reported-by: syzbot+4ef89409a235d804c6c2@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=4ef89409a235d804c6c2
Link: https://lore.kernel.org/all/20251217054908.178907-1-kartikey406@gmail.com/T/ [v1]
Signed-off-by: Deepanshu Kartikey <kartikey406@gmail.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Link: https://patch.msgid.link/20251218012355.279940-1-kartikey406@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-01-08 10:17:14 +01:00
Frode Nordahl
b282b2a9ee erspan: Initialize options_len before referencing options.
commit 35ddf66c65 upstream.

The struct ip_tunnel_info has a flexible array member named
options that is protected by a counted_by(options_len)
attribute.

The compiler will use this information to enforce runtime bounds
checking deployed by FORTIFY_SOURCE string helpers.

As laid out in the GCC documentation, the counter must be
initialized before the first reference to the flexible array
member.

After scanning through the files that use struct ip_tunnel_info
and also refer to options or options_len, it appears the normal
case is to use the ip_tunnel_info_opts_set() helper.

Said helper would initialize options_len properly before copying
data into options, however in the GRE ERSPAN code a partial
update is done, preventing the use of the helper function.

Before this change the handling of ERSPAN traffic in GRE tunnels
would cause a kernel panic when the kernel is compiled with
GCC 15+ and having FORTIFY_SOURCE configured:

memcpy: detected buffer overflow: 4 byte write of buffer size 0

Call Trace:
 <IRQ>
 __fortify_panic+0xd/0xf
 erspan_rcv.cold+0x68/0x83
 ? ip_route_input_slow+0x816/0x9d0
 gre_rcv+0x1b2/0x1c0
 gre_rcv+0x8e/0x100
 ? raw_v4_input+0x2a0/0x2b0
 ip_protocol_deliver_rcu+0x1ea/0x210
 ip_local_deliver_finish+0x86/0x110
 ip_local_deliver+0x65/0x110
 ? ip_rcv_finish_core+0xd6/0x360
 ip_rcv+0x186/0x1a0

Cc: stable@vger.kernel.org
Link: https://gcc.gnu.org/onlinedocs/gcc/Common-Variable-Attributes.html#index-counted_005fby-variable-attribute
Reported-at: https://launchpad.net/bugs/2129580
Fixes: bb5e62f2d5 ("net: Add options as a flexible array to struct ip_tunnel_info")
Signed-off-by: Frode Nordahl <fnordahl@ubuntu.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20251213101338.4693-1-fnordahl@ubuntu.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-01-08 10:17:12 +01:00
Jouni Malinen
a21704df40 wifi: mac80211: Discard Beacon frames to non-broadcast address
commit 193d18f605 upstream.

Beacon frames are required to be sent to the broadcast address, see IEEE
Std 802.11-2020, 11.1.3.1 ("The Address 1 field of the Beacon .. frame
shall be set to the broadcast address"). A unicast Beacon frame might be
used as a targeted attack to get one of the associated STAs to do
something (e.g., using CSA to move it to another channel). As such, it
is better have strict filtering for this on the received side and
discard all Beacon frames that are sent to an unexpected address.

This is even more important for cases where beacon protection is used.
The current implementation in mac80211 is correctly discarding unicast
Beacon frames if the Protected Frame bit in the Frame Control field is
set to 0. However, if that bit is set to 1, the logic used for checking
for configured BIGTK(s) does not actually work. If the driver does not
have logic for dropping unicast Beacon frames with Protected Frame bit
1, these frames would be accepted in mac80211 processing as valid Beacon
frames even though they are not protected. This would allow beacon
protection to be bypassed. While the logic for checking beacon
protection could be extended to cover this corner case, a more generic
check for discard all Beacon frames based on A1=unicast address covers
this without needing additional changes.

Address all these issues by dropping received Beacon frames if they are
sent to a non-broadcast address.

Cc: stable@vger.kernel.org
Fixes: af2d14b01c ("mac80211: Beacon protection using the new BIGTK (STA)")
Signed-off-by: Jouni Malinen <jouni.malinen@oss.qualcomm.com>
Link: https://patch.msgid.link/20251215151134.104501-1-jouni.malinen@oss.qualcomm.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-01-08 10:17:12 +01:00
Paolo Abeni
25f1ae942c mptcp: fallback earlier on simult connection
commit 71154bbe49 upstream.

Syzkaller reports a simult-connect race leading to inconsistent fallback
status:

  WARNING: CPU: 3 PID: 33 at net/mptcp/subflow.c:1515 subflow_data_ready+0x40b/0x7c0 net/mptcp/subflow.c:1515
  Modules linked in:
  CPU: 3 UID: 0 PID: 33 Comm: ksoftirqd/3 Not tainted syzkaller #0 PREEMPT(full)
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
  RIP: 0010:subflow_data_ready+0x40b/0x7c0 net/mptcp/subflow.c:1515
  Code: 89 ee e8 78 61 3c f6 40 84 ed 75 21 e8 8e 66 3c f6 44 89 fe bf 07 00 00 00 e8 c1 61 3c f6 41 83 ff 07 74 09 e8 76 66 3c f6 90 <0f> 0b 90 e8 6d 66 3c f6 48 89 df e8 e5 ad ff ff 31 ff 89 c5 89 c6
  RSP: 0018:ffffc900006cf338 EFLAGS: 00010246
  RAX: 0000000000000000 RBX: ffff888031acd100 RCX: ffffffff8b7f2abf
  RDX: ffff88801e6ea440 RSI: ffffffff8b7f2aca RDI: 0000000000000005
  RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000007
  R10: 0000000000000004 R11: 0000000000002c10 R12: ffff88802ba69900
  R13: 1ffff920000d9e67 R14: ffff888046f81800 R15: 0000000000000004
  FS:  0000000000000000(0000) GS:ffff8880d69bc000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 0000560fc0ca1670 CR3: 0000000032c3a000 CR4: 0000000000352ef0
  Call Trace:
   <TASK>
   tcp_data_queue+0x13b0/0x4f90 net/ipv4/tcp_input.c:5197
   tcp_rcv_state_process+0xfdf/0x4ec0 net/ipv4/tcp_input.c:6922
   tcp_v6_do_rcv+0x492/0x1740 net/ipv6/tcp_ipv6.c:1672
   tcp_v6_rcv+0x2976/0x41e0 net/ipv6/tcp_ipv6.c:1918
   ip6_protocol_deliver_rcu+0x188/0x1520 net/ipv6/ip6_input.c:438
   ip6_input_finish+0x1e4/0x4b0 net/ipv6/ip6_input.c:489
   NF_HOOK include/linux/netfilter.h:318 [inline]
   NF_HOOK include/linux/netfilter.h:312 [inline]
   ip6_input+0x105/0x2f0 net/ipv6/ip6_input.c:500
   dst_input include/net/dst.h:471 [inline]
   ip6_rcv_finish net/ipv6/ip6_input.c:79 [inline]
   NF_HOOK include/linux/netfilter.h:318 [inline]
   NF_HOOK include/linux/netfilter.h:312 [inline]
   ipv6_rcv+0x264/0x650 net/ipv6/ip6_input.c:311
   __netif_receive_skb_one_core+0x12d/0x1e0 net/core/dev.c:5979
   __netif_receive_skb+0x1d/0x160 net/core/dev.c:6092
   process_backlog+0x442/0x15e0 net/core/dev.c:6444
   __napi_poll.constprop.0+0xba/0x550 net/core/dev.c:7494
   napi_poll net/core/dev.c:7557 [inline]
   net_rx_action+0xa9f/0xfe0 net/core/dev.c:7684
   handle_softirqs+0x216/0x8e0 kernel/softirq.c:579
   run_ksoftirqd kernel/softirq.c:968 [inline]
   run_ksoftirqd+0x3a/0x60 kernel/softirq.c:960
   smpboot_thread_fn+0x3f7/0xae0 kernel/smpboot.c:160
   kthread+0x3c2/0x780 kernel/kthread.c:463
   ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148
   ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
   </TASK>

The TCP subflow can process the simult-connect syn-ack packet after
transitioning to TCP_FIN1 state, bypassing the MPTCP fallback check,
as the sk_state_change() callback is not invoked for * -> FIN_WAIT1
transitions.

That will move the msk socket to an inconsistent status and the next
incoming data will hit the reported splat.

Close the race moving the simult-fallback check at the earliest possible
stage - that is at syn-ack generation time.

About the fixes tags: [2] was supposed to also fix this issue introduced
by [3]. [1] is required as a dependence: it was not explicitly marked as
a fix, but it is one and it has already been backported before [3]. In
other words, this commit should be backported up to [3], including [2]
and [1] if that's not already there.

Fixes: 23e89e8ee7 ("tcp: Don't drop SYN+ACK for simultaneous connect().") [1]
Fixes: 4fd19a3070 ("mptcp: fix inconsistent state on fastopen race") [2]
Fixes: 1e777f39b4 ("mptcp: add MSG_FASTOPEN sendmsg flag support") [3]
Cc: stable@vger.kernel.org
Reported-by: syzbot+0ff6b771b4f7a5bce83b@syzkaller.appspotmail.com
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/586
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20251212-net-mptcp-subflow_data_ready-warn-v1-1-d1f9fd1c36c8@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-01-08 10:17:09 +01:00
Jens Axboe
089e50f29e af_unix: don't post cmsg for SO_INQ unless explicitly asked for
commit 4d1442979e upstream.

A previous commit added SO_INQ support for AF_UNIX (SOCK_STREAM), but it
posts a SCM_INQ cmsg even if just msg->msg_get_inq is set. This is
incorrect, as ->msg_get_inq is just the caller asking for the remainder
to be passed back in msg->msg_inq, it has nothing to do with cmsg. The
original commit states that this is done to make sockets
io_uring-friendly", but it's actually incorrect as io_uring doesn't use
cmsg headers internally at all, and it's actively wrong as this means
that cmsg's are always posted if someone does recvmsg via io_uring.

Fix that up by only posting a cmsg if u->recvmsg_inq is set.

Additionally, mirror how TCP handles inquiry handling in that it should
only be done for a successful return. This makes the logic for the two
identical.

Cc: stable@vger.kernel.org
Fixes: df30285b36 ("af_unix: Introduce SO_INQ.")
Reported-by: Julian Orth <ju.orth@gmail.com>
Link: https://github.com/axboe/liburing/issues/1509
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/07adc0c2-2c3b-4d08-8af1-1c466a40b6a8@kernel.dk
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-01-08 10:17:09 +01:00
Jiayuan Chen
787515ccb2 ipv6: fix a BUG in rt6_get_pcpu_route() under PREEMPT_RT
[ Upstream commit 1adaea51c6 ]

On PREEMPT_RT kernels, after rt6_get_pcpu_route() returns NULL, the
current task can be preempted. Another task running on the same CPU
may then execute rt6_make_pcpu_route() and successfully install a
pcpu_rt entry. When the first task resumes execution, its cmpxchg()
in rt6_make_pcpu_route() will fail because rt6i_pcpu is no longer
NULL, triggering the BUG_ON(prev). It's easy to reproduce it by adding
mdelay() after rt6_get_pcpu_route().

Using preempt_disable/enable is not appropriate here because
ip6_rt_pcpu_alloc() may sleep.

Fix this by handling the cmpxchg() failure gracefully on PREEMPT_RT:
free our allocation and return the existing pcpu_rt installed by
another task. The BUG_ON is replaced by WARN_ON_ONCE for non-PREEMPT_RT
kernels where such races should not occur.

Link: https://syzkaller.appspot.com/bug?extid=9b35e9bc0951140d13e6
Fixes: d2d6422f8b ("x86: Allow to enable PREEMPT_RT.")
Reported-by: syzbot+9b35e9bc0951140d13e6@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/6918cd88.050a0220.1c914e.0045.GAE@google.com/T/
Signed-off-by: Jiayuan Chen <jiayuan.chen@linux.dev>
Link: https://patch.msgid.link/20251223051413.124687-1-jiayuan.chen@linux.dev
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-08 10:16:49 +01:00
Pwnverse
92d900aac3 net: rose: fix invalid array index in rose_kill_by_device()
[ Upstream commit 6595beb40f ]

rose_kill_by_device() collects sockets into a local array[] and then
iterates over them to disconnect sockets bound to a device being brought
down.

The loop mistakenly indexes array[cnt] instead of array[i]. For cnt <
ARRAY_SIZE(array), this reads an uninitialized entry; for cnt ==
ARRAY_SIZE(array), it is an out-of-bounds read. Either case can lead to
an invalid socket pointer dereference and also leaks references taken
via sock_hold().

Fix the index to use i.

Fixes: 64b8bc7d5f ("net/rose: fix races in rose_kill_by_device()")
Co-developed-by: Fatma Alwasmi <falwasmi@purdue.edu>
Signed-off-by: Fatma Alwasmi <falwasmi@purdue.edu>
Signed-off-by: Pwnverse <stanksal@purdue.edu>
Link: https://patch.msgid.link/20251222212227.4116041-1-ritviktanksalkar@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-08 10:16:49 +01:00
Vadim Fedorenko
ffd335167d net: fib: restore ECMP balance from loopback
[ Upstream commit 6e17474aa9 ]

Preference of nexthop with source address broke ECMP for packets with
source addresses which are not in the broadcast domain, but rather added
to loopback/dummy interfaces. Original behaviour was to balance over
nexthops while now it uses the latest nexthop from the group. To fix the
issue introduce next hop scoring system where next hops with source
address equal to requested will always have higher priority.

For the case with 198.51.100.1/32 assigned to dummy0 and routed using
192.0.2.0/24 and 203.0.113.0/24 networks:

2: dummy0: <BROADCAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN group default qlen 1000
    link/ether d6:54:8a:ff:78:f5 brd ff:ff:ff:ff:ff:ff
    inet 198.51.100.1/32 scope global dummy0
       valid_lft forever preferred_lft forever
7: veth1@if6: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether 06:ed:98:87:6d:8a brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet 192.0.2.2/24 scope global veth1
       valid_lft forever preferred_lft forever
    inet6 fe80::4ed:98ff:fe87:6d8a/64 scope link proto kernel_ll
       valid_lft forever preferred_lft forever
9: veth3@if8: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether ae:75:23:38:a0:d2 brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet 203.0.113.2/24 scope global veth3
       valid_lft forever preferred_lft forever
    inet6 fe80::ac75:23ff:fe38:a0d2/64 scope link proto kernel_ll
       valid_lft forever preferred_lft forever

~ ip ro list:
default
	nexthop via 192.0.2.1 dev veth1 weight 1
	nexthop via 203.0.113.1 dev veth3 weight 1
192.0.2.0/24 dev veth1 proto kernel scope link src 192.0.2.2
203.0.113.0/24 dev veth3 proto kernel scope link src 203.0.113.2

before:
   for i in {1..255} ; do ip ro get 10.0.0.$i; done | grep veth | awk ' {print $(NF-2)}' | sort | uniq -c:
    255 veth3

after:
   for i in {1..255} ; do ip ro get 10.0.0.$i; done | grep veth | awk ' {print $(NF-2)}' | sort | uniq -c:
    122 veth1
    133 veth3

Fixes: 32607a332c ("ipv4: prefer multipath nexthop that matches source address")
Signed-off-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20251221192639.3911901-1-vadim.fedorenko@linux.dev
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-08 10:16:49 +01:00
Ido Schimmel
e3fc381320 ipv4: Fix reference count leak when using error routes with nexthop objects
[ Upstream commit ac782f4e3b ]

When a nexthop object is deleted, it is marked as dead and then
fib_table_flush() is called to flush all the routes that are using the
dead nexthop.

The current logic in fib_table_flush() is to only flush error routes
(e.g., blackhole) when it is called as part of network namespace
dismantle (i.e., with flush_all=true). Therefore, error routes are not
flushed when their nexthop object is deleted:

 # ip link add name dummy1 up type dummy
 # ip nexthop add id 1 dev dummy1
 # ip route add 198.51.100.1/32 nhid 1
 # ip route add blackhole 198.51.100.2/32 nhid 1
 # ip nexthop del id 1
 # ip route show
 blackhole 198.51.100.2 nhid 1 dev dummy1

As such, they keep holding a reference on the nexthop object which in
turn holds a reference on the nexthop device, resulting in a reference
count leak:

 # ip link del dev dummy1
 [   70.516258] unregister_netdevice: waiting for dummy1 to become free. Usage count = 2

Fix by flushing error routes when their nexthop is marked as dead.

IPv6 does not suffer from this problem.

Fixes: 493ced1ac4 ("ipv4: Allow routes to use nexthop objects")
Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Closes: https://lore.kernel.org/netdev/d943f806-4da6-4970-ac28-b9373b0e63ac@I-love.SAKURA.ne.jp/
Reported-by: syzbot+881d65229ca4f9ae8c84@syzkaller.appspotmail.com
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/20251221144829.197694-1-idosch@nvidia.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-08 10:16:48 +01:00
Will Rosenberg
73744ad569 ipv6: BUG() in pskb_expand_head() as part of calipso_skbuff_setattr()
[ Upstream commit 58fc7342b5 ]

There exists a kernel oops caused by a BUG_ON(nhead < 0) at
net/core/skbuff.c:2232 in pskb_expand_head().
This bug is triggered as part of the calipso_skbuff_setattr()
routine when skb_cow() is passed headroom > INT_MAX
(i.e. (int)(skb_headroom(skb) + len_delta) < 0).

The root cause of the bug is due to an implicit integer cast in
__skb_cow(). The check (headroom > skb_headroom(skb)) is meant to ensure
that delta = headroom - skb_headroom(skb) is never negative, otherwise
we will trigger a BUG_ON in pskb_expand_head(). However, if
headroom > INT_MAX and delta <= -NET_SKB_PAD, the check passes, delta
becomes negative, and pskb_expand_head() is passed a negative value for
nhead.

Fix the trigger condition in calipso_skbuff_setattr(). Avoid passing
"negative" headroom sizes to skb_cow() within calipso_skbuff_setattr()
by only using skb_cow() to grow headroom.

PoC:
	Using `netlabelctl` tool:

        netlabelctl map del default
        netlabelctl calipso add pass doi:7
        netlabelctl map add default address:0::1/128 protocol:calipso,7

        Then run the following PoC:

        int fd = socket(AF_INET6, SOCK_DGRAM, IPPROTO_UDP);

        // setup msghdr
        int cmsg_size = 2;
        int cmsg_len = 0x60;
        struct msghdr msg;
        struct sockaddr_in6 dest_addr;
        struct cmsghdr * cmsg = (struct cmsghdr *) calloc(1,
                        sizeof(struct cmsghdr) + cmsg_len);
        msg.msg_name = &dest_addr;
        msg.msg_namelen = sizeof(dest_addr);
        msg.msg_iov = NULL;
        msg.msg_iovlen = 0;
        msg.msg_control = cmsg;
        msg.msg_controllen = cmsg_len;
        msg.msg_flags = 0;

        // setup sockaddr
        dest_addr.sin6_family = AF_INET6;
        dest_addr.sin6_port = htons(31337);
        dest_addr.sin6_flowinfo = htonl(31337);
        dest_addr.sin6_addr = in6addr_loopback;
        dest_addr.sin6_scope_id = 31337;

        // setup cmsghdr
        cmsg->cmsg_len = cmsg_len;
        cmsg->cmsg_level = IPPROTO_IPV6;
        cmsg->cmsg_type = IPV6_HOPOPTS;
        char * hop_hdr = (char *)cmsg + sizeof(struct cmsghdr);
        hop_hdr[1] = 0x9; //set hop size - (0x9 + 1) * 8 = 80

        sendmsg(fd, &msg, 0);

Fixes: 2917f57b6b ("calipso: Allow the lsm to label the skbuff directly.")
Suggested-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Will Rosenberg <whrosenb@asu.edu>
Acked-by: Paul Moore <paul@paul-moore.com>
Link: https://patch.msgid.link/20251219173637.797418-1-whrosenb@asu.edu
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-08 10:16:48 +01:00