linux/net/core
Eric Dumazet 3265aab073 net: avoid potential UAF in default_operstate()
[ Upstream commit 750e516033 ]

syzbot reported an UAF in default_operstate() [1]

Issue is a race between device and netns dismantles.

After calling __rtnl_unlock() from netdev_run_todo(),
we can not assume the netns of each device is still alive.

Make sure the device is not in NETREG_UNREGISTERED state,
and add an ASSERT_RTNL() before the call to
__dev_get_by_index().

We might move this ASSERT_RTNL() in __dev_get_by_index()
in the future.

[1]

BUG: KASAN: slab-use-after-free in __dev_get_by_index+0x5d/0x110 net/core/dev.c:852
Read of size 8 at addr ffff888043eba1b0 by task syz.0.0/5339

CPU: 0 UID: 0 PID: 5339 Comm: syz.0.0 Not tainted 6.12.0-syzkaller-10296-gaaf20f870da0 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
 <TASK>
  __dump_stack lib/dump_stack.c:94 [inline]
  dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
  print_address_description mm/kasan/report.c:378 [inline]
  print_report+0x169/0x550 mm/kasan/report.c:489
  kasan_report+0x143/0x180 mm/kasan/report.c:602
  __dev_get_by_index+0x5d/0x110 net/core/dev.c:852
  default_operstate net/core/link_watch.c:51 [inline]
  rfc2863_policy+0x224/0x300 net/core/link_watch.c:67
  linkwatch_do_dev+0x3e/0x170 net/core/link_watch.c:170
  netdev_run_todo+0x461/0x1000 net/core/dev.c:10894
  rtnl_unlock net/core/rtnetlink.c:152 [inline]
  rtnl_net_unlock include/linux/rtnetlink.h:133 [inline]
  rtnl_dellink+0x760/0x8d0 net/core/rtnetlink.c:3520
  rtnetlink_rcv_msg+0x791/0xcf0 net/core/rtnetlink.c:6911
  netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2541
  netlink_unicast_kernel net/netlink/af_netlink.c:1321 [inline]
  netlink_unicast+0x7f6/0x990 net/netlink/af_netlink.c:1347
  netlink_sendmsg+0x8e4/0xcb0 net/netlink/af_netlink.c:1891
  sock_sendmsg_nosec net/socket.c:711 [inline]
  __sock_sendmsg+0x221/0x270 net/socket.c:726
  ____sys_sendmsg+0x52a/0x7e0 net/socket.c:2583
  ___sys_sendmsg net/socket.c:2637 [inline]
  __sys_sendmsg+0x269/0x350 net/socket.c:2669
  do_syscall_x64 arch/x86/entry/common.c:52 [inline]
  do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2a3cb80809
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:00007f2a3d9cd058 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f2a3cd45fa0 RCX: 00007f2a3cb80809
RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000000000008
RBP: 00007f2a3cbf393e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f2a3cd45fa0 R15: 00007ffd03bc65c8
 </TASK>

Allocated by task 5339:
  kasan_save_stack mm/kasan/common.c:47 [inline]
  kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
  poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
  __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:394
  kasan_kmalloc include/linux/kasan.h:260 [inline]
  __kmalloc_cache_noprof+0x243/0x390 mm/slub.c:4314
  kmalloc_noprof include/linux/slab.h:901 [inline]
  kmalloc_array_noprof include/linux/slab.h:945 [inline]
  netdev_create_hash net/core/dev.c:11870 [inline]
  netdev_init+0x10c/0x250 net/core/dev.c:11890
  ops_init+0x31e/0x590 net/core/net_namespace.c:138
  setup_net+0x287/0x9e0 net/core/net_namespace.c:362
  copy_net_ns+0x33f/0x570 net/core/net_namespace.c:500
  create_new_namespaces+0x425/0x7b0 kernel/nsproxy.c:110
  unshare_nsproxy_namespaces+0x124/0x180 kernel/nsproxy.c:228
  ksys_unshare+0x57d/0xa70 kernel/fork.c:3314
  __do_sys_unshare kernel/fork.c:3385 [inline]
  __se_sys_unshare kernel/fork.c:3383 [inline]
  __x64_sys_unshare+0x38/0x40 kernel/fork.c:3383
  do_syscall_x64 arch/x86/entry/common.c:52 [inline]
  do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 12:
  kasan_save_stack mm/kasan/common.c:47 [inline]
  kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
  kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:582
  poison_slab_object mm/kasan/common.c:247 [inline]
  __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264
  kasan_slab_free include/linux/kasan.h:233 [inline]
  slab_free_hook mm/slub.c:2338 [inline]
  slab_free mm/slub.c:4598 [inline]
  kfree+0x196/0x420 mm/slub.c:4746
  netdev_exit+0x65/0xd0 net/core/dev.c:11992
  ops_exit_list net/core/net_namespace.c:172 [inline]
  cleanup_net+0x802/0xcc0 net/core/net_namespace.c:632
  process_one_work kernel/workqueue.c:3229 [inline]
  process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310
  worker_thread+0x870/0xd30 kernel/workqueue.c:3391
  kthread+0x2f0/0x390 kernel/kthread.c:389
  ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
  ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

The buggy address belongs to the object at ffff888043eba000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 432 bytes inside of
 freed 2048-byte region [ffff888043eba000, ffff888043eba800)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x43eb8
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x4fff00000000040(head|node=1|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 04fff00000000040 ffff88801ac42000 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000080008 00000001f5000000 0000000000000000
head: 04fff00000000040 ffff88801ac42000 dead000000000122 0000000000000000
head: 0000000000000000 0000000000080008 00000001f5000000 0000000000000000
head: 04fff00000000003 ffffea00010fae01 ffffffffffffffff 0000000000000000
head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5339, tgid 5338 (syz.0.0), ts 69674195892, free_ts 69663220888
  set_page_owner include/linux/page_owner.h:32 [inline]
  post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1556
  prep_new_page mm/page_alloc.c:1564 [inline]
  get_page_from_freelist+0x3649/0x3790 mm/page_alloc.c:3474
  __alloc_pages_noprof+0x292/0x710 mm/page_alloc.c:4751
  alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265
  alloc_slab_page+0x6a/0x140 mm/slub.c:2408
  allocate_slab+0x5a/0x2f0 mm/slub.c:2574
  new_slab mm/slub.c:2627 [inline]
  ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3815
  __slab_alloc+0x58/0xa0 mm/slub.c:3905
  __slab_alloc_node mm/slub.c:3980 [inline]
  slab_alloc_node mm/slub.c:4141 [inline]
  __do_kmalloc_node mm/slub.c:4282 [inline]
  __kmalloc_noprof+0x2e6/0x4c0 mm/slub.c:4295
  kmalloc_noprof include/linux/slab.h:905 [inline]
  sk_prot_alloc+0xe0/0x210 net/core/sock.c:2165
  sk_alloc+0x38/0x370 net/core/sock.c:2218
  __netlink_create+0x65/0x260 net/netlink/af_netlink.c:629
  __netlink_kernel_create+0x174/0x6f0 net/netlink/af_netlink.c:2015
  netlink_kernel_create include/linux/netlink.h:62 [inline]
  uevent_net_init+0xed/0x2d0 lib/kobject_uevent.c:783
  ops_init+0x31e/0x590 net/core/net_namespace.c:138
  setup_net+0x287/0x9e0 net/core/net_namespace.c:362
page last free pid 1032 tgid 1032 stack trace:
  reset_page_owner include/linux/page_owner.h:25 [inline]
  free_pages_prepare mm/page_alloc.c:1127 [inline]
  free_unref_page+0xdf9/0x1140 mm/page_alloc.c:2657
  __slab_free+0x31b/0x3d0 mm/slub.c:4509
  qlink_free mm/kasan/quarantine.c:163 [inline]
  qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179
  kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286
  __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329
  kasan_slab_alloc include/linux/kasan.h:250 [inline]
  slab_post_alloc_hook mm/slub.c:4104 [inline]
  slab_alloc_node mm/slub.c:4153 [inline]
  kmem_cache_alloc_node_noprof+0x1d9/0x380 mm/slub.c:4205
  __alloc_skb+0x1c3/0x440 net/core/skbuff.c:668
  alloc_skb include/linux/skbuff.h:1323 [inline]
  alloc_skb_with_frags+0xc3/0x820 net/core/skbuff.c:6612
  sock_alloc_send_pskb+0x91a/0xa60 net/core/sock.c:2881
  sock_alloc_send_skb include/net/sock.h:1797 [inline]
  mld_newpack+0x1c3/0xaf0 net/ipv6/mcast.c:1747
  add_grhead net/ipv6/mcast.c:1850 [inline]
  add_grec+0x1492/0x19a0 net/ipv6/mcast.c:1988
  mld_send_initial_cr+0x228/0x4b0 net/ipv6/mcast.c:2234
  ipv6_mc_dad_complete+0x88/0x490 net/ipv6/mcast.c:2245
  addrconf_dad_completed+0x712/0xcd0 net/ipv6/addrconf.c:4342
 addrconf_dad_work+0xdc2/0x16f0
  process_one_work kernel/workqueue.c:3229 [inline]
  process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310

Memory state around the buggy address:
 ffff888043eba080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888043eba100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888043eba180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                     ^
 ffff888043eba200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888043eba280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb

Fixes: 8c55facecd ("net: linkwatch: only report IF_OPER_LOWERLAYERDOWN if iflink is actually down")
Reported-by: syzbot+1939f24bdb783e9e43d9@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/674f3a18.050a0220.48a03.0041.GAE@google.com/T/#u
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://patch.msgid.link/20241203170933.2449307-1-edumazet@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
History 2024-12-14 19:59:40 +01:00
..
bpf_sk_storage.c bpf: Add length check for SK_DIAG_BPF_STORAGE_REQ_MAP_FD parsing 2023-07-27 10:07:56 -07:00
datagram.c net: fix rc7's __skb_datagram_iter() 2024-07-18 13:21:13 +02:00
dev.c net: skip offload for NETIF_F_IPV6_CSUM if ipv6 header contains extension 2024-11-08 16:28:19 +01:00
dev.h net: fix removing a namespace with conflicting altnames 2024-01-31 16:19:01 -08:00
dev_addr_lists.c net: extract a few internals from netdevice.h 2022-04-07 20:32:09 -07:00
dev_addr_lists_test.c kunit: Use KUNIT_EXPECT_MEMEQ macro 2022-10-27 02:40:14 -06:00
dev_ioctl.c net: omit ndo_hwtstamp_get() call when possible in dev_set_hwtstamp_phylib() 2023-08-06 13:25:10 +01:00
drop_monitor.c drop_monitor: replace spin_lock by raw_spin_lock 2024-06-27 13:49:01 +02:00
dst.c net: do not delay dst_entries_add() in dst_release() 2024-10-17 15:24:28 +02:00
dst_cache.c ipv6: introduce dst_rt6_info() helper 2024-12-14 19:59:35 +01:00
failover.c net: failover: use IFF_NO_ADDRCONF flag to prevent ipv6 addrconf 2022-12-12 15:18:25 -08:00
fib_notifier.c net: fib_notifier: propagate extack down to the notifier block callback 2019-10-04 11:10:56 -07:00
fib_rules.c fib: expand fib_rule_policy 2021-12-16 07:18:35 -08:00
filter.c ipv6: introduce dst_rt6_info() helper 2024-12-14 19:59:35 +01:00
flow_dissector.c net: flow_dissector: use DEBUG_NET_WARN_ON_ONCE 2024-08-03 08:54:05 +02:00
flow_offload.c tc: flower: Enable offload support IPSEC SPI field. 2023-08-02 10:09:32 +01:00
gen_estimator.c net: use unrcu_pointer() helper 2024-12-09 10:32:10 +01:00
gen_stats.c net: Remove the obsolte u64_stats_fetch_*_irq() users (net). 2022-10-28 20:13:54 -07:00
gro.c net: Add netif_get_gro_max_size helper for GRO 2024-10-10 11:57:16 +02:00
gro_cells.c net: drop the weight argument from netif_napi_add 2022-09-28 18:57:14 -07:00
gso.c net: move gso declarations and functions to their own files 2023-06-10 00:11:41 -07:00
hwbm.c net: hwbm: Make the hwbm_pool lock a mutex 2019-06-09 19:40:10 -07:00
link_watch.c net: avoid potential UAF in default_operstate() 2024-12-14 19:59:40 +01:00
lwt_bpf.c lwt: Fix return values of BPF xmit ops 2023-08-18 16:05:26 +02:00
lwtunnel.c xfrm: lwtunnel: squelch kernel warning in case XFRM encap type is not available 2022-10-12 10:45:51 +02:00
Makefile net: move gso declarations and functions to their own files 2023-06-10 00:11:41 -07:00
neighbour.c neighbour: Don't let neigh_forced_gc() disable preemption for long 2024-01-20 11:51:43 +01:00
net-procfs.c net-sysfs: display two backlog queue len separately 2023-03-22 12:03:52 +01:00
net-sysfs.c ethtool: check device is present when getting link settings 2024-09-04 13:28:26 +02:00
net-sysfs.h net-sysfs: add netdev_change_owner() 2020-02-26 20:07:25 -08:00
net-traces.c udp6: add a missing call into udp_fail_queue_rcv_skb tracepoint 2023-07-07 09:16:52 +01:00
net_namespace.c netns: Make get_net_ns() handle zero refcount net 2024-06-27 13:49:06 +02:00
netclassid_cgroup.c core: Variable type completion 2022-08-31 09:40:34 +01:00
netdev-genl-gen.c net: ynl: prefix uAPI header include with uapi/ 2023-05-26 10:30:14 +01:00
netdev-genl-gen.h net: ynl: prefix uAPI header include with uapi/ 2023-05-26 10:30:14 +01:00
netdev-genl.c netdev-genl: use struct genl_info for reply construction 2023-08-15 15:01:03 -07:00
netevent.c net: core: Correct function name netevent_unregister_notifier() in the kerneldoc 2021-03-28 17:56:56 -07:00
netpoll.c netpoll: Ensure clean state on setup failures 2024-10-10 11:57:26 +02:00
netprio_cgroup.c bpf, cgroups: Fix cgroup v2 fallback on v1/v2 mixed mode 2021-09-13 16:35:58 -07:00
of_net.c net: Explicitly include correct DT includes 2023-07-27 20:33:16 -07:00
page_pool.c net: page_pool: add missing free_percpu when page_pool_init fail 2023-11-20 11:59:34 +01:00
pktgen.c kthread: add kthread_stop_put 2024-06-12 11:12:52 +02:00
ptp_classifier.c ptp: Add generic PTP is_sync() function 2022-03-07 11:31:34 +00:00
request_sock.c tcp: make sure init the accept_queue's spinlocks once 2024-01-31 16:19:00 -08:00
rtnetlink.c net: fix crash when config small gso_max_size/gso_ipv4_max_size 2024-11-08 16:28:18 +01:00
scm.c io_uring/unix: drop usage of io_uring socket 2024-03-26 18:19:09 -04:00
secure_seq.c tcp: Fix data-races around sysctl knobs related to SYN option. 2022-07-20 10:14:49 +01:00
selftests.c net: core: constify mac addrs in selftests 2021-10-24 13:59:44 +01:00
skbuff.c net: core: reject skb_copy(_expand) for fraglist GSO skbs 2024-05-17 12:02:06 +02:00
skmsg.c bpf: fix recursive lock when verdict program return SK_PASS 2024-12-09 10:32:12 +01:00
sock.c net/socket: Break down __sys_getsockopt 2024-09-12 11:11:34 +02:00
sock_destructor.h skb_expand_head() adjust skb->truesize incorrectly 2021-10-22 12:35:51 -07:00
sock_diag.c net: use unrcu_pointer() helper 2024-12-09 10:32:10 +01:00
sock_map.c bpf, sockmap: SK_DROP on attempted redirects of unsupported af_vsock 2024-11-01 01:58:24 +01:00
sock_reuseport.c soreuseport: Fix socket selection for SO_INCOMING_CPU. 2022-10-25 11:35:16 +02:00
stream.c net: Return error from sk_stream_wait_connect() if sk_wait_event() fails 2024-01-01 12:42:30 +00:00
sysctl_net_core.c net: make SK_MEMORY_PCPU_RESERV tunable 2024-05-02 16:32:36 +02:00
timestamping.c net: Introduce a new MII time stamping interface. 2019-12-25 19:51:33 -08:00
tso.c net: tso: inline tso_count_descs() 2022-12-12 15:04:39 -08:00
utils.c net: core: inet[46]_pton strlen len types 2022-11-01 21:14:39 -07:00
xdp.c xdp: fix invalid wait context of page_pool_destroy() 2024-08-03 08:53:44 +02:00