Commit graph

69,785 commits

Author SHA1 Message Date
Deepanshu Kartikey
e02a1c33f1 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>
2026-01-19 13:10:03 +01:00
Pwnverse
ed2639414d 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>
2026-01-19 13:09:58 +01:00
Ido Schimmel
33ff5c207c 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>
2026-01-19 13:09:58 +01:00
Will Rosenberg
6b75224245 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>
2026-01-19 13:09:57 +01:00
Bagas Sanjaya
6b3a6cb349 net: bridge: Describe @tunnel_hash member in net_bridge_vlan_group struct
[ Upstream commit f79f9b7ace ]

Sphinx reports kernel-doc warning:

WARNING: ./net/bridge/br_private.h:267 struct member 'tunnel_hash' not described in 'net_bridge_vlan_group'

Fix it by describing @tunnel_hash member.

Fixes: efa5356b0d ("bridge: per vlan dst_metadata netlink support")
Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20251218042936.24175-2-bagasdotme@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-19 13:09:57 +01:00
Eric Dumazet
41a1a3140a ip6_gre: make ip6gre_header() robust
[ Upstream commit db5b4e39c4 ]

Over the years, syzbot found many ways to crash the kernel
in ip6gre_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 ip6gre device.

[1]
skbuff: skb_under_panic: text:ffffffff8a1d69a8 len:136 put:40 head:ffff888059bc7000 data:ffff888059bc6fe8 tail:0x70 end:0x6c0 dev:team0
------------[ cut here ]------------
 kernel BUG at net/core/skbuff.c:213 !
 <TASK>
  skb_under_panic net/core/skbuff.c:223 [inline]
  skb_push+0xc3/0xe0 net/core/skbuff.c:2641
  ip6gre_header+0xc8/0x790 net/ipv6/ip6_gre.c:1371
  dev_hard_header include/linux/netdevice.h:3436 [inline]
  neigh_connected_output+0x286/0x460 net/core/neighbour.c:1618
  neigh_output include/net/neighbour.h:556 [inline]
  ip6_finish_output2+0xfb3/0x1480 net/ipv6/ip6_output.c:136
 __ip6_finish_output net/ipv6/ip6_output.c:-1 [inline]
  ip6_finish_output+0x234/0x7d0 net/ipv6/ip6_output.c:220
  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

Fixes: c12b395a46 ("gre: Support GRE over IPv6")
Reported-by: syzbot+43a2ebcf2a64b1102d64@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/693b002c.a70a0220.33cd7b.0033.GAE@google.com/T/#u
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20251211173550.2032674-1-edumazet@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-19 13:09:56 +01:00
Toke Høiland-Jørgensen
052e5db5be net: openvswitch: Avoid needlessly taking the RTNL on vport destroy
[ Upstream commit 5498227676 ]

The openvswitch teardown code will immediately call
ovs_netdev_detach_dev() in response to a NETDEV_UNREGISTER notification.
It will then start the dp_notify_work workqueue, which will later end up
calling the vport destroy() callback. This callback takes the RTNL to do
another ovs_netdev_detach_port(), which in this case is unnecessary.
This causes extra pressure on the RTNL, in some cases leading to
"unregister_netdevice: waiting for XX to become free" warnings on
teardown.

We can straight-forwardly avoid the extra RTNL lock acquisition by
checking the device flags before taking the lock, and skip the locking
altogether if the IFF_OVS_DATAPATH flag has already been unset.

Fixes: b07c26511e ("openvswitch: fix vport-netdev unregister")
Tested-by: Adrian Moreno <amorenoz@redhat.com>
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Acked-by: Eelco Chaudron <echaudro@redhat.com>
Acked-by: Aaron Conole <aconole@redhat.com>
Link: https://patch.msgid.link/20251211115006.228876-1-toke@redhat.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-19 13:09:56 +01:00
Joshua Rogers
685889472f svcrdma: return 0 on success from svc_rdma_copy_inline_range
commit 94972027ab upstream.

The function comment specifies 0 on success and -EINVAL on invalid
parameters. Make the tail return 0 after a successful copy loop.

Fixes: d7cc739726 ("svcrdma: support multiple Read chunks per RPC")
Cc: stable@vger.kernel.org
Signed-off-by: Joshua Rogers <linux@joshua.hu>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-01-19 13:09:54 +01:00
Ilya Dryomov
145d140abd libceph: make decode_pool() more resilient against corrupted osdmaps
commit 8c73851271 upstream.

If the osdmap is (maliciously) corrupted such that the encoded length
of ceph_pg_pool envelope is less than what is expected for a particular
encoding version, out-of-bounds reads may ensue because the only bounds
check that is there is based on that length value.

This patch adds explicit bounds checks for each field that is decoded
or skipped.

Cc: stable@vger.kernel.org
Reported-by: ziming zhang <ezrakiez@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Xiubo Li <xiubli@redhat.com>
Tested-by: ziming zhang <ezrakiez@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-01-19 13:09:52 +01:00
Shaurya Rane
c851e43b88 net/hsr: fix NULL pointer dereference in prp_get_untagged_frame()
commit 188e0fa5a6 upstream.

prp_get_untagged_frame() calls __pskb_copy() to create frame->skb_std
but doesn't check if the allocation failed. If __pskb_copy() returns
NULL, skb_clone() is called with a NULL pointer, causing a crash:

Oops: general protection fault, probably for non-canonical address 0xdffffc000000000f: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000078-0x000000000000007f]
CPU: 0 UID: 0 PID: 5625 Comm: syz.1.18 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:skb_clone+0xd7/0x3a0 net/core/skbuff.c:2041
Code: 03 42 80 3c 20 00 74 08 4c 89 f7 e8 23 29 05 f9 49 83 3e 00 0f 85 a0 01 00 00 e8 94 dd 9d f8 48 8d 6b 7e 49 89 ee 49 c1 ee 03 <43> 0f b6 04 26 84 c0 0f 85 d1 01 00 00 44 0f b6 7d 00 41 83 e7 0c
RSP: 0018:ffffc9000d00f200 EFLAGS: 00010207
RAX: ffffffff892235a1 RBX: 0000000000000000 RCX: ffff88803372a480
RDX: 0000000000000000 RSI: 0000000000000820 RDI: 0000000000000000
RBP: 000000000000007e R08: ffffffff8f7d0f77 R09: 1ffffffff1efa1ee
R10: dffffc0000000000 R11: fffffbfff1efa1ef R12: dffffc0000000000
R13: 0000000000000820 R14: 000000000000000f R15: ffff88805144cc00
FS:  0000555557f6d500(0000) GS:ffff88808d72f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555581d35808 CR3: 000000005040e000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 hsr_forward_do net/hsr/hsr_forward.c:-1 [inline]
 hsr_forward_skb+0x1013/0x2860 net/hsr/hsr_forward.c:741
 hsr_handle_frame+0x6ce/0xa70 net/hsr/hsr_slave.c:84
 __netif_receive_skb_core+0x10b9/0x4380 net/core/dev.c:5966
 __netif_receive_skb_one_core net/core/dev.c:6077 [inline]
 __netif_receive_skb+0x72/0x380 net/core/dev.c:6192
 netif_receive_skb_internal net/core/dev.c:6278 [inline]
 netif_receive_skb+0x1cb/0x790 net/core/dev.c:6337
 tun_rx_batched+0x1b9/0x730 drivers/net/tun.c:1485
 tun_get_user+0x2b65/0x3e90 drivers/net/tun.c:1953
 tun_chr_write_iter+0x113/0x200 drivers/net/tun.c:1999
 new_sync_write fs/read_write.c:593 [inline]
 vfs_write+0x5c9/0xb30 fs/read_write.c:686
 ksys_write+0x145/0x250 fs/read_write.c:738
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0449f8e1ff
Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 f9 92 02 00 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 4c 93 02 00 48
RSP: 002b:00007ffd7ad94c90 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f044a1e5fa0 RCX: 00007f0449f8e1ff
RDX: 000000000000003e RSI: 0000200000000500 RDI: 00000000000000c8
RBP: 00007ffd7ad94d20 R08: 0000000000000000 R09: 0000000000000000
R10: 000000000000003e R11: 0000000000000293 R12: 0000000000000001
R13: 00007f044a1e5fa0 R14: 00007f044a1e5fa0 R15: 0000000000000003
 </TASK>

Add a NULL check immediately after __pskb_copy() to handle allocation
failures gracefully.

Reported-by: syzbot+2fa344348a579b779e05@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=2fa344348a579b779e05
Fixes: f266a683a4 ("net/hsr: Better frame dispatch")
Cc: stable@vger.kernel.org
Signed-off-by: Shaurya Rane <ssrane_b23@ee.vjti.ac.in>
Reviewed-by: Felix Maurer <fmaurer@redhat.com>
Tested-by: Felix Maurer <fmaurer@redhat.com>
Link: https://patch.msgid.link/20251129093718.25320-1-ssrane_b23@ee.vjti.ac.in
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-01-19 13:09:46 +01:00
Gal Pressman
f9dc0f45d2 ethtool: Avoid overflowing userspace buffer on stats query
[ Upstream commit 7b07be1ff1 ]

The ethtool -S command operates across three ioctl calls:
ETHTOOL_GSSET_INFO for the size, ETHTOOL_GSTRINGS for the names, and
ETHTOOL_GSTATS for the values.

If the number of stats changes between these calls (e.g., due to device
reconfiguration), userspace's buffer allocation will be incorrect,
potentially leading to buffer overflow.

Drivers are generally expected to maintain stable stat counts, but some
drivers (e.g., mlx5, bnx2x, bna, ksz884x) use dynamic counters, making
this scenario possible.

Some drivers try to handle this internally:
- bnad_get_ethtool_stats() returns early in case stats.n_stats is not
  equal to the driver's stats count.
- micrel/ksz884x also makes sure not to write anything beyond
  stats.n_stats and overflow the buffer.

However, both use stats.n_stats which is already assigned with the value
returned from get_sset_count(), hence won't solve the issue described
here.

Change ethtool_get_strings(), ethtool_get_stats(),
ethtool_get_phy_stats() to not return anything in case of a mismatch
between userspace's size and get_sset_size(), to prevent buffer
overflow.
The returned n_stats value will be equal to zero, to reflect that
nothing has been returned.

This could result in one of two cases when using upstream ethtool,
depending on when the size change is detected:
1. When detected in ethtool_get_strings():
    # ethtool -S eth2
    no stats available

2. When detected in get stats, all stats will be reported as zero.

Both cases are presumably transient, and a subsequent ethtool call
should succeed.

Other than the overflow avoidance, these two cases are very evident (no
output/cleared stats), which is arguably better than presenting
incorrect/shifted stats.
I also considered returning an error instead of a "silent" response, but
that seems more destructive towards userspace apps.

Notes:
- This patch does not claim to fix the inherent race, it only makes sure
  that we do not overflow the userspace buffer, and makes for a more
  predictable behavior.

- RTNL lock is held during each ioctl, the race window exists between
  the separate ioctl calls when the lock is released.

- Userspace ethtool always fills stats.n_stats, but it is likely that
  these stats ioctls are implemented in other userspace applications
  which might not fill it. The added code checks that it's not zero,
  to prevent any regressions.

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Reviewed-by: Dragos Tatulea <dtatulea@nvidia.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: Gal Pressman <gal@nvidia.com>
Link: https://patch.msgid.link/20251208121901.3203692-1-gal@nvidia.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-19 13:09:44 +01:00
Daniil Tatianin
72d1c4a077 net/ethtool/ioctl: split ethtool_get_phy_stats into multiple helpers
[ Upstream commit 201ed315f9 ]

So that it's easier to follow and make sense of the branching and
various conditions.

Stats retrieval has been split into two separate functions
ethtool_get_phy_stats_phydev & ethtool_get_phy_stats_ethtool.
The former attempts to retrieve the stats using phydev & phy_ops, while
the latter uses ethtool_ops.

Actual n_stats validation & array allocation has been moved into a new
ethtool_vzalloc_stats_array helper.

This also fixes a potential NULL dereference of
ops->get_ethtool_phy_stats where it was getting called in an else branch
unconditionally without making sure it was actually present.

Found by Linux Verification Center (linuxtesting.org) with the SVACE
static analysis tool.

Signed-off-by: Daniil Tatianin <d-tatianin@yandex-team.ru>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Stable-dep-of: 7b07be1ff1 ("ethtool: Avoid overflowing userspace buffer on stats query")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-19 13:09:44 +01:00
Daniil Tatianin
c8666be7c3 net/ethtool/ioctl: remove if n_stats checks from ethtool_get_phy_stats
[ Upstream commit fd4778581d ]

Now that we always early return if we don't have any stats we can remove
these checks as they're no longer necessary.

Signed-off-by: Daniil Tatianin <d-tatianin@yandex-team.ru>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Stable-dep-of: 7b07be1ff1 ("ethtool: Avoid overflowing userspace buffer on stats query")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-19 13:09:44 +01:00
Tom Rix
78f0d7353b ethtool: use phydev variable
[ Upstream commit ccd21ec5b8 ]

In ethtool_get_phy_stats(), the phydev varaible is set to
dev->phydev but dev->phydev is still used.  Replace
dev->phydev uses with phydev.

Signed-off-by: Tom Rix <trix@redhat.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Stable-dep-of: 7b07be1ff1 ("ethtool: Avoid overflowing userspace buffer on stats query")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-19 13:09:44 +01:00
Victor Nogueira
02783a37cb net/sched: ets: Remove drr class from the active list if it changes to strict
[ Upstream commit b1e125ae42 ]

Whenever a user issues an ets qdisc change command, transforming a
drr class into a strict one, the ets code isn't checking whether that
class was in the active list and removing it. This means that, if a
user changes a strict class (which was in the active list) back to a drr
one, that class will be added twice to the active list [1].

Doing so with the following commands:

tc qdisc add dev lo root handle 1: ets bands 2 strict 1
tc qdisc add dev lo parent 1:2 handle 20: \
    tbf rate 8bit burst 100b latency 1s
tc filter add dev lo parent 1: basic classid 1:2
ping -c1 -W0.01 -s 56 127.0.0.1
tc qdisc change dev lo root handle 1: ets bands 2 strict 2
tc qdisc change dev lo root handle 1: ets bands 2 strict 1
ping -c1 -W0.01 -s 56 127.0.0.1

Will trigger the following splat with list debug turned on:

[   59.279014][  T365] ------------[ cut here ]------------
[   59.279452][  T365] list_add double add: new=ffff88801d60e350, prev=ffff88801d60e350, next=ffff88801d60e2c0.
[   59.280153][  T365] WARNING: CPU: 3 PID: 365 at lib/list_debug.c:35 __list_add_valid_or_report+0x17f/0x220
[   59.280860][  T365] Modules linked in:
[   59.281165][  T365] CPU: 3 UID: 0 PID: 365 Comm: tc Not tainted 6.18.0-rc7-00105-g7e9f13163c13-dirty #239 PREEMPT(voluntary)
[   59.281977][  T365] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   59.282391][  T365] RIP: 0010:__list_add_valid_or_report+0x17f/0x220
[   59.282842][  T365] Code: 89 c6 e8 d4 b7 0d ff 90 0f 0b 90 90 31 c0 e9 31 ff ff ff 90 48 c7 c7 e0 a0 22 9f 48 89 f2 48 89 c1 4c 89 c6 e8 b2 b7 0d ff 90 <0f> 0b 90 90 31 c0 e9 0f ff ff ff 48 89 f7 48 89 44 24 10 4c 89 44
...
[   59.288812][  T365] Call Trace:
[   59.289056][  T365]  <TASK>
[   59.289224][  T365]  ? srso_alias_return_thunk+0x5/0xfbef5
[   59.289546][  T365]  ets_qdisc_change+0xd2b/0x1e80
[   59.289891][  T365]  ? __lock_acquire+0x7e7/0x1be0
[   59.290223][  T365]  ? __pfx_ets_qdisc_change+0x10/0x10
[   59.290546][  T365]  ? srso_alias_return_thunk+0x5/0xfbef5
[   59.290898][  T365]  ? __mutex_trylock_common+0xda/0x240
[   59.291228][  T365]  ? __pfx___mutex_trylock_common+0x10/0x10
[   59.291655][  T365]  ? srso_alias_return_thunk+0x5/0xfbef5
[   59.291993][  T365]  ? srso_alias_return_thunk+0x5/0xfbef5
[   59.292313][  T365]  ? trace_contention_end+0xc8/0x110
[   59.292656][  T365]  ? srso_alias_return_thunk+0x5/0xfbef5
[   59.293022][  T365]  ? srso_alias_return_thunk+0x5/0xfbef5
[   59.293351][  T365]  tc_modify_qdisc+0x63a/0x1cf0

Fix this by always checking and removing an ets class from the active list
when changing it to strict.

[1] https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git/tree/net/sched/sch_ets.c?id=ce052b9402e461a9aded599f5b47e76bc727f7de#n663

Fixes: cd9b50adc6 ("net/sched: ets: fix crash when flipping from 'strict' to 'quantum'")
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Victor Nogueira <victor@mojatatu.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Link: https://patch.msgid.link/20251208190125.1868423-1-victor@mojatatu.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-19 13:09:44 +01:00
Junrui Luo
c54091eec6 caif: fix integer underflow in cffrml_receive()
[ Upstream commit 8a11ff0948 ]

The cffrml_receive() function extracts a length field from the packet
header and, when FCS is disabled, subtracts 2 from this length without
validating that len >= 2.

If an attacker sends a malicious packet with a length field of 0 or 1
to an interface with FCS disabled, the subtraction causes an integer
underflow.

This can lead to memory exhaustion and kernel instability, potential
information disclosure if padding contains uninitialized kernel memory.

Fix this by validating that len >= 2 before performing the subtraction.

Reported-by: Yuhao Jiang <danisjiang@gmail.com>
Reported-by: Junrui Luo <moonafterrain@outlook.com>
Fixes: b482cd2053 ("net-caif: add CAIF core protocol stack")
Signed-off-by: Junrui Luo <moonafterrain@outlook.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/SYBPR01MB7881511122BAFEA8212A1608AFA6A@SYBPR01MB7881.ausprd01.prod.outlook.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-19 13:09:44 +01:00
Slavin Liu
312d7cd888 ipvs: fix ipv4 null-ptr-deref in route error path
[ Upstream commit ad891bb3d0 ]

The IPv4 code path in __ip_vs_get_out_rt() calls dst_link_failure()
without ensuring skb->dev is set, leading to a NULL pointer dereference
in fib_compute_spec_dst() when ipv4_link_failure() attempts to send
ICMP destination unreachable messages.

The issue emerged after commit ed0de45a10 ("ipv4: recompile ip options
in ipv4_link_failure") started calling __ip_options_compile() from
ipv4_link_failure(). This code path eventually calls fib_compute_spec_dst()
which dereferences skb->dev. An attempt was made to fix the NULL skb->dev
dereference in commit 0113d9c9d1 ("ipv4: fix null-deref in
ipv4_link_failure"), but it only addressed the immediate dev_net(skb->dev)
dereference by using a fallback device. The fix was incomplete because
fib_compute_spec_dst() later in the call chain still accesses skb->dev
directly, which remains NULL when IPVS calls dst_link_failure().

The crash occurs when:
1. IPVS processes a packet in NAT mode with a misconfigured destination
2. Route lookup fails in __ip_vs_get_out_rt() before establishing a route
3. The error path calls dst_link_failure(skb) with skb->dev == NULL
4. ipv4_link_failure() → ipv4_send_dest_unreach() →
   __ip_options_compile() → fib_compute_spec_dst()
5. fib_compute_spec_dst() dereferences NULL skb->dev

Apply the same fix used for IPv6 in commit 326bf17ea5 ("ipvs: fix
ipv6 route unreach panic"): set skb->dev from skb_dst(skb)->dev before
calling dst_link_failure().

KASAN: null-ptr-deref in range [0x0000000000000328-0x000000000000032f]
CPU: 1 PID: 12732 Comm: syz.1.3469 Not tainted 6.6.114 #2
RIP: 0010:__in_dev_get_rcu include/linux/inetdevice.h:233
RIP: 0010:fib_compute_spec_dst+0x17a/0x9f0 net/ipv4/fib_frontend.c:285
Call Trace:
  <TASK>
  spec_dst_fill net/ipv4/ip_options.c:232
  spec_dst_fill net/ipv4/ip_options.c:229
  __ip_options_compile+0x13a1/0x17d0 net/ipv4/ip_options.c:330
  ipv4_send_dest_unreach net/ipv4/route.c:1252
  ipv4_link_failure+0x702/0xb80 net/ipv4/route.c:1265
  dst_link_failure include/net/dst.h:437
  __ip_vs_get_out_rt+0x15fd/0x19e0 net/netfilter/ipvs/ip_vs_xmit.c:412
  ip_vs_nat_xmit+0x1d8/0xc80 net/netfilter/ipvs/ip_vs_xmit.c:764

Fixes: ed0de45a10 ("ipv4: recompile ip options in ipv4_link_failure")
Signed-off-by: Slavin Liu <slavin452@gmail.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-19 13:09:43 +01:00
Fernando Fernandez Mancera
e1ac8dce3a netfilter: nf_conncount: fix leaked ct in error paths
[ Upstream commit 2e2a720766 ]

There are some situations where ct might be leaked as error paths are
skipping the refcounted check and return immediately. In order to solve
it make sure that the check is always called.

Fixes: be102eb6a0 ("netfilter: nf_conncount: rework API to use sk_buff directly")
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>
2026-01-19 13:09:43 +01:00
Ilya Maximets
3bc2efff20 net: openvswitch: fix middle attribute validation in push_nsh() action
[ Upstream commit 5ace7ef87f ]

The push_nsh() action structure looks like this:

 OVS_ACTION_ATTR_PUSH_NSH(OVS_KEY_ATTR_NSH(OVS_NSH_KEY_ATTR_BASE,...))

The outermost OVS_ACTION_ATTR_PUSH_NSH attribute is OK'ed by the
nla_for_each_nested() inside __ovs_nla_copy_actions().  The innermost
OVS_NSH_KEY_ATTR_BASE/MD1/MD2 are OK'ed by the nla_for_each_nested()
inside nsh_key_put_from_nlattr().  But nothing checks if the attribute
in the middle is OK.  We don't even check that this attribute is the
OVS_KEY_ATTR_NSH.  We just do a double unwrap with a pair of nla_data()
calls - first time directly while calling validate_push_nsh() and the
second time as part of the nla_for_each_nested() macro, which isn't
safe, potentially causing invalid memory access if the size of this
attribute is incorrect.  The failure may not be noticed during
validation due to larger netlink buffer, but cause trouble later during
action execution where the buffer is allocated exactly to the size:

 BUG: KASAN: slab-out-of-bounds in nsh_hdr_from_nlattr+0x1dd/0x6a0 [openvswitch]
 Read of size 184 at addr ffff88816459a634 by task a.out/22624

 CPU: 8 UID: 0 PID: 22624 6.18.0-rc7+ #115 PREEMPT(voluntary)
 Call Trace:
  <TASK>
  dump_stack_lvl+0x51/0x70
  print_address_description.constprop.0+0x2c/0x390
  kasan_report+0xdd/0x110
  kasan_check_range+0x35/0x1b0
  __asan_memcpy+0x20/0x60
  nsh_hdr_from_nlattr+0x1dd/0x6a0 [openvswitch]
  push_nsh+0x82/0x120 [openvswitch]
  do_execute_actions+0x1405/0x2840 [openvswitch]
  ovs_execute_actions+0xd5/0x3b0 [openvswitch]
  ovs_packet_cmd_execute+0x949/0xdb0 [openvswitch]
  genl_family_rcv_msg_doit+0x1d6/0x2b0
  genl_family_rcv_msg+0x336/0x580
  genl_rcv_msg+0x9f/0x130
  netlink_rcv_skb+0x11f/0x370
  genl_rcv+0x24/0x40
  netlink_unicast+0x73e/0xaa0
  netlink_sendmsg+0x744/0xbf0
  __sys_sendto+0x3d6/0x450
  do_syscall_64+0x79/0x2c0
  entry_SYSCALL_64_after_hwframe+0x76/0x7e
  </TASK>

Let's add some checks that the attribute is properly sized and it's
the only one attribute inside the action.  Technically, there is no
real reason for OVS_KEY_ATTR_NSH to be there, as we know that we're
pushing an NSH header already, it just creates extra nesting, but
that's how uAPI works today.  So, keeping as it is.

Fixes: b2d0f5d5dc ("openvswitch: enable NSH support")
Reported-by: Junvy Yang <zhuque@tencent.com>
Signed-off-by: Ilya Maximets <i.maximets@ovn.org>
Acked-by: Eelco Chaudron echaudro@redhat.com
Reviewed-by: Aaron Conole <aconole@redhat.com>
Link: https://patch.msgid.link/20251204105334.900379-1-i.maximets@ovn.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-19 13:09:43 +01:00
Jamal Hadi Salim
c7f6e7cc14 net/sched: ets: Always remove class from active list before deleting in ets_qdisc_change
[ Upstream commit ce052b9402 ]

zdi-disclosures@trendmicro.com says:

The vulnerability is a race condition between `ets_qdisc_dequeue` and
`ets_qdisc_change`.  It leads to UAF on `struct Qdisc` object.
Attacker requires the capability to create new user and network namespace
in order to trigger the bug.
See my additional commentary at the end of the analysis.

Analysis:

static int ets_qdisc_change(struct Qdisc *sch, struct nlattr *opt,
                          struct netlink_ext_ack *extack)
{
...

      // (1) this lock is preventing .change handler (`ets_qdisc_change`)
      //to race with .dequeue handler (`ets_qdisc_dequeue`)
      sch_tree_lock(sch);

      for (i = nbands; i < oldbands; i++) {
              if (i >= q->nstrict && q->classes[i].qdisc->q.qlen)
                      list_del_init(&q->classes[i].alist);
              qdisc_purge_queue(q->classes[i].qdisc);
      }

      WRITE_ONCE(q->nbands, nbands);
      for (i = nstrict; i < q->nstrict; i++) {
              if (q->classes[i].qdisc->q.qlen) {
		      // (2) the class is added to the q->active
                      list_add_tail(&q->classes[i].alist, &q->active);
                      q->classes[i].deficit = quanta[i];
              }
      }
      WRITE_ONCE(q->nstrict, nstrict);
      memcpy(q->prio2band, priomap, sizeof(priomap));

      for (i = 0; i < q->nbands; i++)
              WRITE_ONCE(q->classes[i].quantum, quanta[i]);

      for (i = oldbands; i < q->nbands; i++) {
              q->classes[i].qdisc = queues[i];
              if (q->classes[i].qdisc != &noop_qdisc)
                      qdisc_hash_add(q->classes[i].qdisc, true);
      }

      // (3) the qdisc is unlocked, now dequeue can be called in parallel
      // to the rest of .change handler
      sch_tree_unlock(sch);

      ets_offload_change(sch);
      for (i = q->nbands; i < oldbands; i++) {
	      // (4) we're reducing the refcount for our class's qdisc and
	      //  freeing it
              qdisc_put(q->classes[i].qdisc);
	      // (5) If we call .dequeue between (4) and (5), we will have
	      // a strong UAF and we can control RIP
              q->classes[i].qdisc = NULL;
              WRITE_ONCE(q->classes[i].quantum, 0);
              q->classes[i].deficit = 0;
              gnet_stats_basic_sync_init(&q->classes[i].bstats);
              memset(&q->classes[i].qstats, 0, sizeof(q->classes[i].qstats));
      }
      return 0;
}

Comment:
This happens because some of the classes have their qdiscs assigned to
NULL, but remain in the active list. This commit fixes this issue by always
removing the class from the active list before deleting and freeing its
associated qdisc

Reproducer Steps
(trimmed version of what was sent by zdi-disclosures@trendmicro.com)

```
DEV="${DEV:-lo}"
ROOT_HANDLE="${ROOT_HANDLE👎}"
BAND2_HANDLE="${BAND2_HANDLE:-20:}"   # child under 1:2
PING_BYTES="${PING_BYTES:-48}"
PING_COUNT="${PING_COUNT:-200000}"
PING_DST="${PING_DST:-127.0.0.1}"

SLOW_TBF_RATE="${SLOW_TBF_RATE:-8bit}"
SLOW_TBF_BURST="${SLOW_TBF_BURST:-100b}"
SLOW_TBF_LAT="${SLOW_TBF_LAT:-1s}"

cleanup() {
  tc qdisc del dev "$DEV" root 2>/dev/null
}
trap cleanup EXIT

ip link set "$DEV" up

tc qdisc del dev "$DEV" root 2>/dev/null || true

tc qdisc add dev "$DEV" root handle "$ROOT_HANDLE" ets bands 2 strict 2

tc qdisc add dev "$DEV" parent 1:2 handle "$BAND2_HANDLE" \
  tbf rate "$SLOW_TBF_RATE" burst "$SLOW_TBF_BURST" latency "$SLOW_TBF_LAT"

tc filter add dev "$DEV" parent 1: protocol all prio 1 u32 match u32 0 0 flowid 1:2
tc -s qdisc ls dev $DEV

ping -I "$DEV" -f -c "$PING_COUNT" -s "$PING_BYTES" -W 0.001 "$PING_DST" \
  >/dev/null 2>&1 &
tc qdisc change dev "$DEV" root handle "$ROOT_HANDLE" ets bands 2 strict 0
tc qdisc change dev "$DEV" root handle "$ROOT_HANDLE" ets bands 2 strict 2
tc -s qdisc ls dev $DEV
tc qdisc del dev "$DEV" parent 1:2 || true
tc -s qdisc ls dev $DEV
tc qdisc change dev "$DEV" root handle "$ROOT_HANDLE" ets bands 1 strict 1
```

KASAN report
```
==================================================================
BUG: KASAN: slab-use-after-free in ets_qdisc_dequeue+0x1071/0x11b0 kernel/net/sched/sch_ets.c:481
Read of size 8 at addr ffff8880502fc018 by task ping/12308
>
CPU: 0 UID: 0 PID: 12308 Comm: ping Not tainted 6.18.0-rc4-dirty #1 PREEMPT(full)
Hardware name: QEMU Ubuntu 25.04 PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Call Trace:
 <IRQ>
 __dump_stack kernel/lib/dump_stack.c:94
 dump_stack_lvl+0x100/0x190 kernel/lib/dump_stack.c:120
 print_address_description kernel/mm/kasan/report.c:378
 print_report+0x156/0x4c9 kernel/mm/kasan/report.c:482
 kasan_report+0xdf/0x110 kernel/mm/kasan/report.c:595
 ets_qdisc_dequeue+0x1071/0x11b0 kernel/net/sched/sch_ets.c:481
 dequeue_skb kernel/net/sched/sch_generic.c:294
 qdisc_restart kernel/net/sched/sch_generic.c:399
 __qdisc_run+0x1c9/0x1b00 kernel/net/sched/sch_generic.c:417
 __dev_xmit_skb kernel/net/core/dev.c:4221
 __dev_queue_xmit+0x2848/0x4410 kernel/net/core/dev.c:4729
 dev_queue_xmit kernel/./include/linux/netdevice.h:3365
[...]

Allocated by task 17115:
 kasan_save_stack+0x30/0x50 kernel/mm/kasan/common.c:56
 kasan_save_track+0x14/0x30 kernel/mm/kasan/common.c:77
 poison_kmalloc_redzone kernel/mm/kasan/common.c:400
 __kasan_kmalloc+0xaa/0xb0 kernel/mm/kasan/common.c:417
 kasan_kmalloc kernel/./include/linux/kasan.h:262
 __do_kmalloc_node kernel/mm/slub.c:5642
 __kmalloc_node_noprof+0x34e/0x990 kernel/mm/slub.c:5648
 kmalloc_node_noprof kernel/./include/linux/slab.h:987
 qdisc_alloc+0xb8/0xc30 kernel/net/sched/sch_generic.c:950
 qdisc_create_dflt+0x93/0x490 kernel/net/sched/sch_generic.c:1012
 ets_class_graft+0x4fd/0x800 kernel/net/sched/sch_ets.c:261
 qdisc_graft+0x3e4/0x1780 kernel/net/sched/sch_api.c:1196
[...]

Freed by task 9905:
 kasan_save_stack+0x30/0x50 kernel/mm/kasan/common.c:56
 kasan_save_track+0x14/0x30 kernel/mm/kasan/common.c:77
 __kasan_save_free_info+0x3b/0x70 kernel/mm/kasan/generic.c:587
 kasan_save_free_info kernel/mm/kasan/kasan.h:406
 poison_slab_object kernel/mm/kasan/common.c:252
 __kasan_slab_free+0x5f/0x80 kernel/mm/kasan/common.c:284
 kasan_slab_free kernel/./include/linux/kasan.h:234
 slab_free_hook kernel/mm/slub.c:2539
 slab_free kernel/mm/slub.c:6630
 kfree+0x144/0x700 kernel/mm/slub.c:6837
 rcu_do_batch kernel/kernel/rcu/tree.c:2605
 rcu_core+0x7c0/0x1500 kernel/kernel/rcu/tree.c:2861
 handle_softirqs+0x1ea/0x8a0 kernel/kernel/softirq.c:622
 __do_softirq kernel/kernel/softirq.c:656
[...]

Commentary:

1. Maher Azzouzi working with Trend Micro Zero Day Initiative was reported as
the person who found the issue. I requested to get a proper email to add to the
reported-by tag but got no response. For this reason i will credit the person
i exchanged emails with i.e zdi-disclosures@trendmicro.com

2. Neither i nor Victor who did a much more thorough testing was able to
reproduce a UAF with the PoC or other approaches we tried. We were both able to
reproduce a null ptr deref. After exchange with zdi-disclosures@trendmicro.com
they sent a small change to be made to the code to add an extra delay which
was able to simulate the UAF. i.e, this:
   qdisc_put(q->classes[i].qdisc);
   mdelay(90);
   q->classes[i].qdisc = NULL;

I was informed by Thomas Gleixner(tglx@linutronix.de) that adding delays was
acceptable approach for demonstrating the bug, quote:
"Adding such delays is common exploit validation practice"
The equivalent delay could happen "by virt scheduling the vCPU out, SMIs,
NMIs, PREEMPT_RT enabled kernel"

3. I asked the OP to test and report back but got no response and after a
few days gave up and proceeded to submit this fix.

Fixes: de6d25924c ("net/sched: sch_ets: don't peek at classes beyond 'nbands'")
Reported-by: zdi-disclosures@trendmicro.com
Tested-by: Victor Nogueira <victor@mojatatu.com>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Reviewed-by: Davide Caratti <dcaratti@redhat.com>
Link: https://patch.msgid.link/20251128151919.576920-1-jhs@mojatatu.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-19 13:09:43 +01:00
Wang Liang
09efbf54ee netrom: Fix memory leak in nr_sendmsg()
[ Upstream commit 613d12dd79 ]

syzbot reported a memory leak [1].

When function sock_alloc_send_skb() return NULL in nr_output(), the
original skb is not freed, which was allocated in nr_sendmsg(). Fix this
by freeing it before return.

[1]
BUG: memory leak
unreferenced object 0xffff888129f35500 (size 240):
  comm "syz.0.17", pid 6119, jiffies 4294944652
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 00 10 52 28 81 88 ff ff  ..........R(....
  backtrace (crc 1456a3e4):
    kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
    slab_post_alloc_hook mm/slub.c:4983 [inline]
    slab_alloc_node mm/slub.c:5288 [inline]
    kmem_cache_alloc_node_noprof+0x36f/0x5e0 mm/slub.c:5340
    __alloc_skb+0x203/0x240 net/core/skbuff.c:660
    alloc_skb include/linux/skbuff.h:1383 [inline]
    alloc_skb_with_frags+0x69/0x3f0 net/core/skbuff.c:6671
    sock_alloc_send_pskb+0x379/0x3e0 net/core/sock.c:2965
    sock_alloc_send_skb include/net/sock.h:1859 [inline]
    nr_sendmsg+0x287/0x450 net/netrom/af_netrom.c:1105
    sock_sendmsg_nosec net/socket.c:727 [inline]
    __sock_sendmsg net/socket.c:742 [inline]
    sock_write_iter+0x293/0x2a0 net/socket.c:1195
    new_sync_write fs/read_write.c:593 [inline]
    vfs_write+0x45d/0x710 fs/read_write.c:686
    ksys_write+0x143/0x170 fs/read_write.c:738
    do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
    do_syscall_64+0xa4/0xfa0 arch/x86/entry/syscall_64.c:94
    entry_SYSCALL_64_after_hwframe+0x77/0x7f

Reported-by: syzbot+d7abc36bbbb6d7d40b58@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=d7abc36bbbb6d7d40b58
Tested-by: syzbot+d7abc36bbbb6d7d40b58@syzkaller.appspotmail.com
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Wang Liang <wangliang74@huawei.com>
Link: https://patch.msgid.link/20251129041315.1550766-1-wangliang74@huawei.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-19 13:09:43 +01:00
Nicklas Bo Jensen
754512b096 netfilter: nf_conncount: garbage collection is not skipped when jiffies wrap around
commit df08c94baa upstream.

nf_conncount is supposed to skip garbage collection if it has already
run garbage collection in the same jiffy. Unfortunately, this is broken
when jiffies wrap around which this patch fixes.

The problem is that last_gc in the nf_conncount_list struct is an u32,
but jiffies is an unsigned long which is 8 bytes on my systems. When
those two are compared it only works until last_gc wraps around.

See bug report: https://bugzilla.netfilter.org/show_bug.cgi?id=1778
for more details.

Fixes: d265929930 ("netfilter: nf_conncount: reduce unnecessary GC")
Signed-off-by: Nicklas Bo Jensen <njensen@akamai.com>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-01-19 13:09:40 +01:00
Xiang Mei
38abf6e931 net/sched: sch_cake: Fix incorrect qlen reduction in cake_drop
[ Upstream commit 9fefc78f7f ]

In cake_drop(), qdisc_tree_reduce_backlog() is used to update the qlen
and backlog of the qdisc hierarchy. Its caller, cake_enqueue(), assumes
that the parent qdisc will enqueue the current packet. However, this
assumption breaks when cake_enqueue() returns NET_XMIT_CN: the parent
qdisc stops enqueuing current packet, leaving the tree qlen/backlog
accounting inconsistent. This mismatch can lead to a NULL dereference
(e.g., when the parent Qdisc is qfq_qdisc).

This patch computes the qlen/backlog delta in a more robust way by
observing the difference before and after the series of cake_drop()
calls, and then compensates the qdisc tree accounting if cake_enqueue()
returns NET_XMIT_CN.

To ensure correct compensation when ACK thinning is enabled, a new
variable is introduced to keep qlen unchanged.

Fixes: 15de71d06a ("net/sched: Make cake_enqueue return NET_XMIT_CN when past buffer_limit")
Signed-off-by: Xiang Mei <xmei5@asu.edu>
Reviewed-by: Toke Høiland-Jørgensen <toke@toke.dk>
Link: https://patch.msgid.link/20251128001415.377823-1-xmei5@asu.edu
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-19 13:09:36 +01:00
Fernando Fernandez Mancera
53bc0ac47f netfilter: nft_connlimit: update the count if add was skipped
[ Upstream commit 69894e5b4c ]

Connlimit expression can be used for all kind of packets and not only
for packets with connection state new. See this ruleset as example:

table ip filter {
        chain input {
                type filter hook input priority filter; policy accept;
                tcp dport 22 ct count over 4 counter
        }
}

Currently, if the connection count goes over the limit the counter will
count the packets. When a connection is closed, the connection count
won't decrement as it should because it is only updated for new
connections due to an optimization on __nf_conncount_add() that prevents
updating the list if the connection is duplicated.

To solve this problem, check whether the connection was skipped and if
so, update the list. Adjust count_tree() too so the same fix is applied
for xt_connlimit.

Fixes: 976afca1ce ("netfilter: nf_conncount: Early exit in nf_conncount_lookup() and cleanup")
Closes: https://lore.kernel.org/netfilter/trinity-85c72a88-d762-46c3-be97-36f10e5d9796-1761173693813@3c-app-mailcom-bs12/
Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-19 13:09:35 +01:00
Fernando Fernandez Mancera
b160895d6b netfilter: nf_conncount: rework API to use sk_buff directly
[ Upstream commit be102eb6a0 ]

When using nf_conncount infrastructure for non-confirmed connections a
duplicated track is possible due to an optimization introduced since
commit d265929930 ("netfilter: nf_conncount: reduce unnecessary GC").

In order to fix this introduce a new conncount API that receives
directly an sk_buff struct.  It fetches the tuple and zone and the
corresponding ct from it. It comes with both existing conncount variants
nf_conncount_count_skb() and nf_conncount_add_skb(). In addition remove
the old API and adjust all the users to use the new one.

This way, for each sk_buff struct it is possible to check if there is a
ct present and already confirmed. If so, skip the add operation.

Fixes: d265929930 ("netfilter: nf_conncount: reduce unnecessary GC")
Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Stable-dep-of: 69894e5b4c ("netfilter: nft_connlimit: update the count if add was skipped")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-19 13:09:35 +01:00
William Tu
be69850b46 netfilter: nf_conncount: reduce unnecessary GC
[ Upstream commit d265929930 ]

Currently nf_conncount can trigger garbage collection (GC)
at multiple places. Each GC process takes a spin_lock_bh
to traverse the nf_conncount_list. We found that when testing
port scanning use two parallel nmap, because the number of
connection increase fast, the nf_conncount_count and its
subsequent call to __nf_conncount_add take too much time,
causing several CPU lockup. This happens when user set the
conntrack limit to +20,000, because the larger the limit,
the longer the list that GC has to traverse.

The patch mitigate the performance issue by avoiding unnecessary
GC with a timestamp. Whenever nf_conncount has done a GC,
a timestamp is updated, and beforce the next time GC is
triggered, we make sure it's more than a jiffies.
By doin this we can greatly reduce the CPU cycles and
avoid the softirq lockup.

To reproduce it in OVS,
$ ovs-appctl dpctl/ct-set-limits zone=1,limit=20000
$ ovs-appctl dpctl/ct-get-limits

At another machine, runs two nmap
$ nmap -p1- <IP>
$ nmap -p1- <IP>

Signed-off-by: William Tu <u9012063@gmail.com>
Co-authored-by: Yifeng Sun <pkusunyifeng@gmail.com>
Reported-by: Greg Rose <gvrose8192@gmail.com>
Suggested-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Stable-dep-of: 69894e5b4c ("netfilter: nft_connlimit: update the count if add was skipped")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-19 13:09:35 +01:00
Pablo Neira Ayuso
aea811b4cf netfilter: flowtable: check for maximum number of encapsulations in bridge vlan
[ Upstream commit 634f3853cc ]

Add a sanity check to skip path discovery if the maximum number of
encapsulation is reached. While at it, check for underflow too.

Fixes: 26267bf9bb ("netfilter: flowtable: bridge vlan hardware offload and switchdev")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-19 13:09:35 +01:00
Kuniyuki Iwashima
4af48d5cb6 sctp: Defer SCTP_DBG_OBJCNT_DEC() to sctp_destroy_sock().
[ Upstream commit 622e8838a2 ]

SCTP_DBG_OBJCNT_INC() is called only when sctp_init_sock()
returns 0 after successfully allocating sctp_sk(sk)->ep.

OTOH, SCTP_DBG_OBJCNT_DEC() is called in sctp_close().

The code seems to expect that the socket is always exposed
to userspace once SCTP_DBG_OBJCNT_INC() is incremented, but
there is a path where the assumption is not true.

In sctp_accept(), sctp_sock_migrate() could fail after
sctp_init_sock().

Then, sk_common_release() does not call inet_release() nor
sctp_close().  Instead, it calls sk->sk_prot->destroy().

Let's move SCTP_DBG_OBJCNT_DEC() from sctp_close() to
sctp_destroy_sock().

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Acked-by: Xin Long <lucien.xin@gmail.com>
Link: https://patch.msgid.link/20251023231751.4168390-2-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-19 13:09:24 +01:00
Xuanqiang Luo
0314de9675 inet: Avoid ehash lookup race in inet_ehash_insert()
[ Upstream commit 1532ed0d07 ]

Since ehash lookups are lockless, if one CPU performs a lookup while
another concurrently deletes and inserts (removing reqsk and inserting sk),
the lookup may fail to find the socket, an RST may be sent.

The call trace map is drawn as follows:
   CPU 0                           CPU 1
   -----                           -----
				inet_ehash_insert()
                                spin_lock()
                                sk_nulls_del_node_init_rcu(osk)
__inet_lookup_established()
	(lookup failed)
                                __sk_nulls_add_node_rcu(sk, list)
                                spin_unlock()

As both deletion and insertion operate on the same ehash chain, this patch
introduces a new sk_nulls_replace_node_init_rcu() helper functions to
implement atomic replacement.

Fixes: 5e0724d027 ("tcp/dccp: fix hashdance race for passive sessions")
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Jiayuan Chen <jiayuan.chen@linux.dev>
Signed-off-by: Xuanqiang Luo <luoxuanqiang@kylinos.cn>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20251015020236.431822-3-xuanqiang.luo@linux.dev
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-19 13:09:23 +01:00
Sabrina Dubroca
e1d414c571 xfrm: flush all states in xfrm_state_fini
[ Upstream commit 42e42562c9 ]

While reverting commit f75a2804da ("xfrm: destroy xfrm_state
synchronously on net exit path"), I incorrectly changed
xfrm_state_flush's "proto" argument back to IPSEC_PROTO_ANY. This
reverts some of the changes in commit dbb2483b2a ("xfrm: clean up
xfrm protocol checks"), and leads to some states not being removed
when we exit the netns.

Pass 0 instead of IPSEC_PROTO_ANY from both xfrm_state_fini
xfrm6_tunnel_net_exit, so that xfrm_state_flush deletes all states.

Fixes: 2a198bbec6 ("Revert "xfrm: destroy xfrm_state synchronously on net exit path"")
Reported-by: syzbot+6641a61fe0e2e89ae8c5@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=6641a61fe0e2e89ae8c5
Tested-by: syzbot+6641a61fe0e2e89ae8c5@syzkaller.appspotmail.com
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-19 13:09:19 +01:00
Sabrina Dubroca
1dad653643 xfrm: also call xfrm_state_delete_tunnel at destroy time for states that were never added
[ Upstream commit 10deb69864 ]

In commit b441cf3f8c ("xfrm: delete x->tunnel as we delete x"), I
missed the case where state creation fails between full
initialization (->init_state has been called) and being inserted on
the lists.

In this situation, ->init_state has been called, so for IPcomp
tunnels, the fallback tunnel has been created and added onto the
lists, but the user state never gets added, because we fail before
that. The user state doesn't go through __xfrm_state_delete, so we
don't call xfrm_state_delete_tunnel for those states, and we end up
leaking the FB tunnel.

There are several codepaths affected by this: the add/update paths, in
both net/key and xfrm, and the migrate code (xfrm_migrate,
xfrm_state_migrate). A "proper" rollback of the init_state work would
probably be doable in the add/update code, but for migrate it gets
more complicated as multiple states may be involved.

At some point, the new (not-inserted) state will be destroyed, so call
xfrm_state_delete_tunnel during xfrm_state_gc_destroy. Most states
will have their fallback tunnel cleaned up during __xfrm_state_delete,
which solves the issue that b441cf3f8c (and other patches before it)
aimed at. All states (including FB tunnels) will be removed from the
lists once xfrm_state_fini has called flush_work(&xfrm_state_gc_work).

Reported-by: syzbot+999eb23467f83f9bf9bf@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=999eb23467f83f9bf9bf
Fixes: b441cf3f8c ("xfrm: delete x->tunnel as we delete x")
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-19 13:09:18 +01:00
Sabrina Dubroca
9f2d85ead8 Revert "xfrm: destroy xfrm_state synchronously on net exit path"
[ Upstream commit 2a198bbec6 ]

This reverts commit f75a2804da.

With all states (whether user or kern) removed from the hashtables
during deletion, there's no need for synchronous destruction of
states. xfrm6_tunnel states still need to have been destroyed (which
will be the case when its last user is deleted (not destroyed)) so
that xfrm6_tunnel_free_spi removes it from the per-netns hashtable
before the netns is destroyed.

This has the benefit of skipping one synchronize_rcu per state (in
__xfrm_state_destroy(sync=true)) when we exit a netns.

Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-19 13:09:18 +01:00
Sabrina Dubroca
4b2c17d0f9 xfrm: delete x->tunnel as we delete x
[ Upstream commit b441cf3f8c ]

The ipcomp fallback tunnels currently get deleted (from the various
lists and hashtables) as the last user state that needed that fallback
is destroyed (not deleted). If a reference to that user state still
exists, the fallback state will remain on the hashtables/lists,
triggering the WARN in xfrm_state_fini. Because of those remaining
references, the fix in commit f75a2804da ("xfrm: destroy xfrm_state
synchronously on net exit path") is not complete.

We recently fixed one such situation in TCP due to defered freeing of
skbs (commit 9b6412e697 ("tcp: drop secpath at the same time as we
currently drop dst")). This can also happen due to IP reassembly: skbs
with a secpath remain on the reassembly queue until netns
destruction. If we can't guarantee that the queues are flushed by the
time xfrm_state_fini runs, there may still be references to a (user)
xfrm_state, preventing the timely deletion of the corresponding
fallback state.

Instead of chasing each instance of skbs holding a secpath one by one,
this patch fixes the issue directly within xfrm, by deleting the
fallback state as soon as the last user state depending on it has been
deleted. Destruction will still happen when the final reference is
dropped.

A separate lockdep class for the fallback state is required since
we're going to lock x->tunnel while x is locked.

Fixes: 9d4139c769 ("netns xfrm: per-netns xfrm_state_all list")
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-19 13:09:18 +01:00
Alex Lu
f7b814a132 Bluetooth: Add more enc key size check
[ Upstream commit 04a342cc49 ]

When we are slave role and receives l2cap conn req when encryption has
started, we should check the enc key size to avoid KNOB attack or BLUFFS
attack.
>From SIG recommendation, implementations are advised to reject
service-level connections on an encrypted baseband link with key
strengths below 7 octets.
A simple and clear way to achieve this is to place the enc key size
check in hci_cc_read_enc_key_size()

The btmon log below shows the case that lacks enc key size check.

> HCI Event: Connect Request (0x04) plen 10
        Address: BB:22:33:44:55:99 (OUI BB-22-33)
        Class: 0x480104
          Major class: Computer (desktop, notebook, PDA, organizers)
          Minor class: Desktop workstation
          Capturing (Scanner, Microphone)
          Telephony (Cordless telephony, Modem, Headset)
        Link type: ACL (0x01)
< HCI Command: Accept Connection Request (0x01|0x0009) plen 7
        Address: BB:22:33:44:55:99 (OUI BB-22-33)
        Role: Peripheral (0x01)
> HCI Event: Command Status (0x0f) plen 4
      Accept Connection Request (0x01|0x0009) ncmd 2
        Status: Success (0x00)
> HCI Event: Connect Complete (0x03) plen 11
        Status: Success (0x00)
        Handle: 1
        Address: BB:22:33:44:55:99 (OUI BB-22-33)
        Link type: ACL (0x01)
        Encryption: Disabled (0x00)
...

> HCI Event: Encryption Change (0x08) plen 4
        Status: Success (0x00)
        Handle: 1 Address: BB:22:33:44:55:99 (OUI BB-22-33)
        Encryption: Enabled with E0 (0x01)
< HCI Command: Read Encryption Key Size (0x05|0x0008) plen 2
        Handle: 1 Address: BB:22:33:44:55:99 (OUI BB-22-33)
> HCI Event: Command Complete (0x0e) plen 7
      Read Encryption Key Size (0x05|0x0008) ncmd 2
        Status: Success (0x00)
        Handle: 1 Address: BB:22:33:44:55:99 (OUI BB-22-33)
        Key size: 6
// We should check the enc key size
...

> ACL Data RX: Handle 1 flags 0x02 dlen 12
      L2CAP: Connection Request (0x02) ident 3 len 4
        PSM: 25 (0x0019)
        Source CID: 64
< ACL Data TX: Handle 1 flags 0x00 dlen 16
      L2CAP: Connection Response (0x03) ident 3 len 8
        Destination CID: 64
        Source CID: 64
        Result: Connection pending (0x0001)
        Status: Authorization pending (0x0002)
> HCI Event: Number of Completed Packets (0x13) plen 5
        Num handles: 1
        Handle: 1 Address: BB:22:33:44:55:99 (OUI BB-22-33)
        Count: 1
        #35: len 16 (25 Kb/s)
        Latency: 5 msec (2-7 msec ~4 msec)
< ACL Data TX: Handle 1 flags 0x00 dlen 16
      L2CAP: Connection Response (0x03) ident 3 len 8
        Destination CID: 64
        Source CID: 64
        Result: Connection successful (0x0000)
        Status: No further information available (0x0000)

Cc: stable@vger.kernel.org
Signed-off-by: Alex Lu <alex_lu@realsil.com.cn>
Signed-off-by: Max Chou <max.chou@realtek.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
[ Nazar Kalashnikov: change status to 
rp_status due to function parameter conflict ]
Signed-off-by: Nazar Kalashnikov <sivartiwe@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-12-07 06:09:36 +09:00
Jiayuan Chen
7ee8f015eb mptcp: Fix proto fallback detection with BPF
commit c77b3b79a9 upstream.

The sockmap feature allows bpf syscall from userspace, or based
on bpf sockops, replacing the sk_prot of sockets during protocol stack
processing with sockmap's custom read/write interfaces.
'''
tcp_rcv_state_process()
  syn_recv_sock()/subflow_syn_recv_sock()
    tcp_init_transfer(BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB)
      bpf_skops_established       <== sockops
        bpf_sock_map_update(sk)   <== call bpf helper
          tcp_bpf_update_proto()  <== update sk_prot
'''

When the server has MPTCP enabled but the client sends a TCP SYN
without MPTCP, subflow_syn_recv_sock() performs a fallback on the
subflow, replacing the subflow sk's sk_prot with the native sk_prot.
'''
subflow_syn_recv_sock()
  subflow_ulp_fallback()
    subflow_drop_ctx()
      mptcp_subflow_ops_undo_override()
'''

Then, this subflow can be normally used by sockmap, which replaces the
native sk_prot with sockmap's custom sk_prot. The issue occurs when the
user executes accept::mptcp_stream_accept::mptcp_fallback_tcp_ops().
Here, it uses sk->sk_prot to compare with the native sk_prot, but this
is incorrect when sockmap is used, as we may incorrectly set
sk->sk_socket->ops.

This fix uses the more generic sk_family for the comparison instead.

Additionally, this also prevents a WARNING from occurring:

result from ./scripts/decode_stacktrace.sh:
------------[ cut here ]------------
WARNING: CPU: 0 PID: 337 at net/mptcp/protocol.c:68 mptcp_stream_accept \
(net/mptcp/protocol.c:4005)
Modules linked in:
...

PKRU: 55555554
Call Trace:
<TASK>
do_accept (net/socket.c:1989)
__sys_accept4 (net/socket.c:2028 net/socket.c:2057)
__x64_sys_accept (net/socket.c:2067)
x64_sys_call (arch/x86/entry/syscall_64.c:41)
do_syscall_64 (arch/x86/entry/syscall_64.c:63 arch/x86/entry/syscall_64.c:94)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
RIP: 0033:0x7f87ac92b83d

---[ end trace 0000000000000000 ]---

Fixes: 0b4f33def7 ("mptcp: fix tcp fallback crash")
Signed-off-by: Jiayuan Chen <jiayuan.chen@linux.dev>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Cc: <stable@vger.kernel.org>
Link: https://patch.msgid.link/20251111060307.194196-3-jiayuan.chen@linux.dev
[ Conflicts in protocol.c, because commit 8e2b8a9fa5 ("mptcp: don't
  overwrite sock_ops in mptcp_is_tcpsk()") is not in this version. It
  changes the logic on how and where the sock_ops is overridden in case
  of passive fallback. To fix this, mptcp_is_tcpsk() is modified to use
  the family, but first, a check of the protocol is required to continue
  returning 'false' in case of MPTCP socket. ]
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-12-07 06:09:36 +09:00
Paolo Abeni
dad1e44ed9 mptcp: avoid unneeded subflow-level drops
commit 4f102d747c upstream.

The rcv window is shared among all the subflows. Currently, MPTCP sync
the TCP-level rcv window with the MPTCP one at tcp_transmit_skb() time.

The above means that incoming data may sporadically observe outdated
TCP-level rcv window and being wrongly dropped by TCP.

Address the issue checking for the edge condition before queuing the
data at TCP level, and eventually syncing the rcv window as needed.

Note that the issue is actually present from the very first MPTCP
implementation, but backports older than the blamed commit below will
range from impossible to useless.

Before:

  $ nstat -n; sleep 1; nstat -z TcpExtBeyondWindow
  TcpExtBeyondWindow              14                 0.0

After:

  $ nstat -n; sleep 1; nstat -z TcpExtBeyondWindow
  TcpExtBeyondWindow              0                  0.0

Fixes: fa3fe2b150 ("mptcp: track window announced to peer")
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/20251118-net-mptcp-misc-fixes-6-18-rc6-v1-2-806d3781c95f@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
[ Conflicts in options.c, because the new rwin_update() helper has been
  added after __mptcp_snd_una_update() which is not in this version --
  see commit -- and then causing conflicts in the context. There were
  also some conflicts in mptcp_set_rwin(), because commit f3589be0c4
  ("mptcp: never shrink offered window") is not in this version. Only
  the update of subflow->rcv_wnd_sent has been added. Also
  msk->rcv_wnd_sent is a u64 before this commit: in rwin_update(),
  READ_ONCE() is used instead of atomic64_read(&). ]
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-12-07 06:09:36 +09:00
ziming zhang
f22c55a20a libceph: prevent potential out-of-bounds writes in handle_auth_session_key()
commit 7fce830ecd upstream.

The len field originates from untrusted network packets. Boundary
checks have been added to prevent potential out-of-bounds writes when
decrypting the connection secret or processing service tickets.

[ 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>
2025-12-07 06:09:36 +09:00
Ilya Dryomov
05ec43e9a9 libceph: fix potential use-after-free in have_mon_and_osd_map()
commit 076381c261 upstream.

The wait loop in __ceph_open_session() can race with the client
receiving a new monmap or osdmap shortly after the initial map is
received.  Both ceph_monc_handle_map() and handle_one_map() install
a new map immediately after freeing the old one

    kfree(monc->monmap);
    monc->monmap = monmap;

    ceph_osdmap_destroy(osdc->osdmap);
    osdc->osdmap = newmap;

under client->monc.mutex and client->osdc.lock respectively, but
because neither is taken in have_mon_and_osd_map() it's possible for
client->monc.monmap->epoch and client->osdc.osdmap->epoch arms in

    client->monc.monmap && client->monc.monmap->epoch &&
        client->osdc.osdmap && client->osdc.osdmap->epoch;

condition to dereference an already freed map.  This happens to be
reproducible with generic/395 and generic/397 with KASAN enabled:

    BUG: KASAN: slab-use-after-free in have_mon_and_osd_map+0x56/0x70
    Read of size 4 at addr ffff88811012d810 by task mount.ceph/13305
    CPU: 2 UID: 0 PID: 13305 Comm: mount.ceph Not tainted 6.14.0-rc2-build2+ #1266
    ...
    Call Trace:
    <TASK>
    have_mon_and_osd_map+0x56/0x70
    ceph_open_session+0x182/0x290
    ceph_get_tree+0x333/0x680
    vfs_get_tree+0x49/0x180
    do_new_mount+0x1a3/0x2d0
    path_mount+0x6dd/0x730
    do_mount+0x99/0xe0
    __do_sys_mount+0x141/0x180
    do_syscall_64+0x9f/0x100
    entry_SYSCALL_64_after_hwframe+0x76/0x7e
    </TASK>

    Allocated by task 13305:
    ceph_osdmap_alloc+0x16/0x130
    ceph_osdc_init+0x27a/0x4c0
    ceph_create_client+0x153/0x190
    create_fs_client+0x50/0x2a0
    ceph_get_tree+0xff/0x680
    vfs_get_tree+0x49/0x180
    do_new_mount+0x1a3/0x2d0
    path_mount+0x6dd/0x730
    do_mount+0x99/0xe0
    __do_sys_mount+0x141/0x180
    do_syscall_64+0x9f/0x100
    entry_SYSCALL_64_after_hwframe+0x76/0x7e

    Freed by task 9475:
    kfree+0x212/0x290
    handle_one_map+0x23c/0x3b0
    ceph_osdc_handle_map+0x3c9/0x590
    mon_dispatch+0x655/0x6f0
    ceph_con_process_message+0xc3/0xe0
    ceph_con_v1_try_read+0x614/0x760
    ceph_con_workfn+0x2de/0x650
    process_one_work+0x486/0x7c0
    process_scheduled_works+0x73/0x90
    worker_thread+0x1c8/0x2a0
    kthread+0x2ec/0x300
    ret_from_fork+0x24/0x40
    ret_from_fork_asm+0x1a/0x30

Rewrite the wait loop to check the above condition directly with
client->monc.mutex and client->osdc.lock taken as appropriate.  While
at it, improve the timeout handling (previously mount_timeout could be
exceeded in case wait_event_interruptible_timeout() slept more than
once) and access client->auth_err under client->monc.mutex to match
how it's set in finish_auth().

monmap_show() and osdmap_show() now take the respective lock before
accessing the map as well.

Cc: stable@vger.kernel.org
Reported-by: David Howells <dhowells@redhat.com>
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>
2025-12-07 06:09:36 +09:00
Luiz Augusto von Dentz
4475bac822 Bluetooth: SMP: Fix not generating mackey and ltk when repairing
[ Upstream commit 545d7827b2 ]

The change eed467b517 ("Bluetooth: fix passkey uninitialized when used")
introduced a goto that bypasses the creation of temporary mackey and ltk
which are later used by the likes of DHKey Check step.

Later ffee202a78 ("Bluetooth: Always request for user confirmation for
Just Works (LE SC)") which means confirm_hint is always set in case
JUST_WORKS so the branch checking for an existing LTK becomes pointless
as confirm_hint will always be set, so this just merge both cases of
malicious or legitimate devices to be confirmed before continuing with the
pairing procedure.

Link: https://github.com/bluez/bluez/issues/1622
Fixes: eed467b517 ("Bluetooth: fix passkey uninitialized when used")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-12-07 06:09:33 +09:00
Paolo Abeni
0b6a100efd mptcp: do not fallback when OoO is present
[ Upstream commit 1bba3f219c ]

In case of DSS corruption, the MPTCP protocol tries to avoid the subflow
reset if fallback is possible. Such corruptions happen in the receive
path; to ensure fallback is possible the stack additionally needs to
check for OoO data, otherwise the fallback will break the data stream.

Fixes: e32d262c89 ("mptcp: handle consistently DSS corruption")
Cc: stable@vger.kernel.org
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/598
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/20251118-net-mptcp-misc-fixes-6-18-rc6-v1-4-806d3781c95f@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
[ patch mptcp_dss_corruption() ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-12-07 06:09:33 +09:00
Eric Dumazet
e2d1ad2071 mptcp: fix a race in mptcp_pm_del_add_timer()
[ Upstream commit 426358d9be ]

mptcp_pm_del_add_timer() can call sk_stop_timer_sync(sk, &entry->add_timer)
while another might have free entry already, as reported by syzbot.

Add RCU protection to fix this issue.

Also change confusing add_timer variable with stop_timer boolean.

syzbot report:

BUG: KASAN: slab-use-after-free in __timer_delete_sync+0x372/0x3f0 kernel/time/timer.c:1616
Read of size 4 at addr ffff8880311e4150 by task kworker/1:1/44

CPU: 1 UID: 0 PID: 44 Comm: kworker/1:1 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Workqueue: events mptcp_worker
Call Trace:
 <TASK>
  dump_stack_lvl+0x189/0x250 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
  __timer_delete_sync+0x372/0x3f0 kernel/time/timer.c:1616
  sk_stop_timer_sync+0x1b/0x90 net/core/sock.c:3631
  mptcp_pm_del_add_timer+0x283/0x310 net/mptcp/pm.c:362
  mptcp_incoming_options+0x1357/0x1f60 net/mptcp/options.c:1174
  tcp_data_queue+0xca/0x6450 net/ipv4/tcp_input.c:5361
  tcp_rcv_established+0x1335/0x2670 net/ipv4/tcp_input.c:6441
  tcp_v4_do_rcv+0x98b/0xbf0 net/ipv4/tcp_ipv4.c:1931
  tcp_v4_rcv+0x252a/0x2dc0 net/ipv4/tcp_ipv4.c:2374
  ip_protocol_deliver_rcu+0x221/0x440 net/ipv4/ip_input.c:205
  ip_local_deliver_finish+0x3bb/0x6f0 net/ipv4/ip_input.c:239
  NF_HOOK+0x30c/0x3a0 include/linux/netfilter.h:318
  NF_HOOK+0x30c/0x3a0 include/linux/netfilter.h:318
  __netif_receive_skb_one_core net/core/dev.c:6079 [inline]
  __netif_receive_skb+0x143/0x380 net/core/dev.c:6192
  process_backlog+0x31e/0x900 net/core/dev.c:6544
  __napi_poll+0xb6/0x540 net/core/dev.c:7594
  napi_poll net/core/dev.c:7657 [inline]
  net_rx_action+0x5f7/0xda0 net/core/dev.c:7784
  handle_softirqs+0x22f/0x710 kernel/softirq.c:622
  __do_softirq kernel/softirq.c:656 [inline]
  __local_bh_enable_ip+0x1a0/0x2e0 kernel/softirq.c:302
  mptcp_pm_send_ack net/mptcp/pm.c:210 [inline]
 mptcp_pm_addr_send_ack+0x41f/0x500 net/mptcp/pm.c:-1
  mptcp_pm_worker+0x174/0x320 net/mptcp/pm.c:1002
  mptcp_worker+0xd5/0x1170 net/mptcp/protocol.c:2762
  process_one_work kernel/workqueue.c:3263 [inline]
  process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346
  worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
  kthread+0x711/0x8a0 kernel/kthread.c:463
  ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
  ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Allocated by task 44:
  kasan_save_stack mm/kasan/common.c:56 [inline]
  kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
  poison_kmalloc_redzone mm/kasan/common.c:400 [inline]
  __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:417
  kasan_kmalloc include/linux/kasan.h:262 [inline]
  __kmalloc_cache_noprof+0x1ef/0x6c0 mm/slub.c:5748
  kmalloc_noprof include/linux/slab.h:957 [inline]
  mptcp_pm_alloc_anno_list+0x104/0x460 net/mptcp/pm.c:385
  mptcp_pm_create_subflow_or_signal_addr+0xf9d/0x1360 net/mptcp/pm_kernel.c:355
  mptcp_pm_nl_fully_established net/mptcp/pm_kernel.c:409 [inline]
  __mptcp_pm_kernel_worker+0x417/0x1ef0 net/mptcp/pm_kernel.c:1529
  mptcp_pm_worker+0x1ee/0x320 net/mptcp/pm.c:1008
  mptcp_worker+0xd5/0x1170 net/mptcp/protocol.c:2762
  process_one_work kernel/workqueue.c:3263 [inline]
  process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346
  worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
  kthread+0x711/0x8a0 kernel/kthread.c:463
  ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
  ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Freed by task 6630:
  kasan_save_stack mm/kasan/common.c:56 [inline]
  kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
  __kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:587
  kasan_save_free_info mm/kasan/kasan.h:406 [inline]
  poison_slab_object mm/kasan/common.c:252 [inline]
  __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:284
  kasan_slab_free include/linux/kasan.h:234 [inline]
  slab_free_hook mm/slub.c:2523 [inline]
  slab_free mm/slub.c:6611 [inline]
  kfree+0x197/0x950 mm/slub.c:6818
  mptcp_remove_anno_list_by_saddr+0x2d/0x40 net/mptcp/pm.c:158
  mptcp_pm_flush_addrs_and_subflows net/mptcp/pm_kernel.c:1209 [inline]
  mptcp_nl_flush_addrs_list net/mptcp/pm_kernel.c:1240 [inline]
  mptcp_pm_nl_flush_addrs_doit+0x593/0xbb0 net/mptcp/pm_kernel.c:1281
  genl_family_rcv_msg_doit+0x215/0x300 net/netlink/genetlink.c:1115
  genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
  genl_rcv_msg+0x60e/0x790 net/netlink/genetlink.c:1210
  netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2552
  genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
  netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
  netlink_unicast+0x846/0xa10 net/netlink/af_netlink.c:1346
  netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896
  sock_sendmsg_nosec net/socket.c:727 [inline]
  __sock_sendmsg+0x21c/0x270 net/socket.c:742
  ____sys_sendmsg+0x508/0x820 net/socket.c:2630
  ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2684
  __sys_sendmsg net/socket.c:2716 [inline]
  __do_sys_sendmsg net/socket.c:2721 [inline]
  __se_sys_sendmsg net/socket.c:2719 [inline]
  __x64_sys_sendmsg+0x1a1/0x260 net/socket.c:2719
  do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
  do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Cc: stable@vger.kernel.org
Fixes: 00cfd77b90 ("mptcp: retransmit ADD_ADDR when timeout")
Reported-by: syzbot+2a6fbf0f0530375968df@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/691ad3c3.a70a0220.f6df1.0004.GAE@google.com
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Geliang Tang <geliang@kernel.org>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20251117100745.1913963-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
[ applied changes to pm_netlink.c instead of pm.c ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-12-07 06:09:33 +09:00
Paolo Abeni
2cc425276c mptcp: fix premature close in case of fallback
[ Upstream commit 17393fa7b7 ]

I'm observing very frequent self-tests failures in case of fallback when
running on a CONFIG_PREEMPT kernel.

The root cause is that subflow_sched_work_if_closed() closes any subflow
as soon as it is half-closed and has no incoming data pending.

That works well for regular subflows - MPTCP needs bi-directional
connectivity to operate on a given subflow - but for fallback socket is
race prone.

When TCP peer closes the connection before the MPTCP one,
subflow_sched_work_if_closed() will schedule the MPTCP worker to
gracefully close the subflow, and shortly after will do another schedule
to inject and process a dummy incoming DATA_FIN.

On CONFIG_PREEMPT kernel, the MPTCP worker can kick-in and close the
fallback subflow before subflow_sched_work_if_closed() is able to create
the dummy DATA_FIN, unexpectedly interrupting the transfer.

Address the issue explicitly avoiding closing fallback subflows on when
the peer is only half-closed.

Note that, when the subflow is able to create the DATA_FIN before the
worker invocation, the worker will change the msk state before trying to
close the subflow and will skip the latter operation as the msk will not
match anymore the precondition in __mptcp_close_subflow().

Fixes: f09b0ad55a ("mptcp: close subflow when receiving TCP+FIN")
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/20251118-net-mptcp-misc-fixes-6-18-rc6-v1-3-806d3781c95f@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
[ sk -> ssk ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-12-07 06:09:33 +09:00
Paolo Abeni
4c3d91386d mptcp: fix ack generation for fallback msk
[ Upstream commit 5e15395f6d ]

mptcp_cleanup_rbuf() needs to know the last most recent, mptcp-level
rcv_wnd sent, and such information is tracked into the msk->old_wspace
field, updated at ack transmission time by mptcp_write_options().

Fallback socket do not add any mptcp options, such helper is never
invoked, and msk->old_wspace value remain stale. That in turn makes
ack generation at recvmsg() time quite random.

Address the issue ensuring mptcp_write_options() is invoked even for
fallback sockets, and just update the needed info in such a case.

The issue went unnoticed for a long time, as mptcp currently overshots
the fallback socket receive buffer autotune significantly. It is going
to change in the near future.

Fixes: e3859603ba ("mptcp: better msk receive window updates")
Cc: stable@vger.kernel.org
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/594
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Geliang Tang <geliang@kernel.org>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20251118-net-mptcp-misc-fixes-6-18-rc6-v1-1-806d3781c95f@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
[ Adjust context ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-12-07 06:09:33 +09:00
Jiayuan Chen
c22cedbc18 mptcp: Disallow MPTCP subflows from sockmap
[ Upstream commit fbade4bd08 ]

The sockmap feature allows bpf syscall from userspace, or based on bpf
sockops, replacing the sk_prot of sockets during protocol stack processing
with sockmap's custom read/write interfaces.
'''
tcp_rcv_state_process()
  subflow_syn_recv_sock()
    tcp_init_transfer(BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB)
      bpf_skops_established       <== sockops
        bpf_sock_map_update(sk)   <== call bpf helper
          tcp_bpf_update_proto()  <== update sk_prot
'''
Consider two scenarios:

1. When the server has MPTCP enabled and the client also requests MPTCP,
   the sk passed to the BPF program is a subflow sk. Since subflows only
   handle partial data, replacing their sk_prot is meaningless and will
   cause traffic disruption.

2. When the server has MPTCP enabled but the client sends a TCP SYN
   without MPTCP, subflow_syn_recv_sock() performs a fallback on the
   subflow, replacing the subflow sk's sk_prot with the native sk_prot.
   '''
   subflow_ulp_fallback()
    subflow_drop_ctx()
      mptcp_subflow_ops_undo_override()
   '''
   Subsequently, accept::mptcp_stream_accept::mptcp_fallback_tcp_ops()
   converts the subflow to plain TCP.

For the first case, we should prevent it from being combined with sockmap
by setting sk_prot->psock_update_sk_prot to NULL, which will be blocked by
sockmap's own flow.

For the second case, since subflow_syn_recv_sock() has already restored
sk_prot to native tcp_prot/tcpv6_prot, no further action is needed.

Fixes: cec37a6e41 ("mptcp: Handle MP_CAPABLE options for outgoing connections")
Signed-off-by: Jiayuan Chen <jiayuan.chen@linux.dev>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Cc: <stable@vger.kernel.org>
Link: https://patch.msgid.link/20251111060307.194196-2-jiayuan.chen@linux.dev
[ Adjust context ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-12-07 06:09:33 +09:00
Breno Leitao
890472d6fb net: netpoll: fix incorrect refcount handling causing incorrect cleanup
[ Upstream commit 49c8d2c1f9 ]

commit efa95b01da ("netpoll: fix use after free") incorrectly
ignored the refcount and prematurely set dev->npinfo to NULL during
netpoll cleanup, leading to improper behavior and memory leaks.

Scenario causing lack of proper cleanup:

1) A netpoll is associated with a NIC (e.g., eth0) and netdev->npinfo is
   allocated, and refcnt = 1
   - Keep in mind that npinfo is shared among all netpoll instances. In
     this case, there is just one.

2) Another netpoll is also associated with the same NIC and
   npinfo->refcnt += 1.
   - Now dev->npinfo->refcnt = 2;
   - There is just one npinfo associated to the netdev.

3) When the first netpolls goes to clean up:
   - The first cleanup succeeds and clears np->dev->npinfo, ignoring
     refcnt.
     - It basically calls `RCU_INIT_POINTER(np->dev->npinfo, NULL);`
   - Set dev->npinfo = NULL, without proper cleanup
   - No ->ndo_netpoll_cleanup() is either called

4) Now the second target tries to clean up
   - The second cleanup fails because np->dev->npinfo is already NULL.
     * In this case, ops->ndo_netpoll_cleanup() was never called, and
       the skb pool is not cleaned as well (for the second netpoll
       instance)
  - This leaks npinfo and skbpool skbs, which is clearly reported by
    kmemleak.

Revert commit efa95b01da ("netpoll: fix use after free") and adds
clarifying comments emphasizing that npinfo cleanup should only happen
once the refcount reaches zero, ensuring stable and correct netpoll
behavior.

Cc: <stable@vger.kernel.org> # 3.17.x
Cc: Jay Vosburgh <jv@jvosburgh.net>
Fixes: efa95b01da ("netpoll: fix use after free")
Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20251107-netconsole_torture-v10-1-749227b55f63@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
[ Adjust context ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-12-07 06:09:32 +09:00
Shahar Shitrit
699c6cc0f1 net: tls: Cancel RX async resync request on rcd_delta overflow
[ Upstream commit c15d5c62ab ]

When a netdev issues a RX async resync request for a TLS connection,
the TLS module handles it by logging record headers and attempting to
match them to the tcp_sn provided by the device. If a match is found,
the TLS module approves the tcp_sn for resynchronization.

While waiting for a device response, the TLS module also increments
rcd_delta each time a new TLS record is received, tracking the distance
from the original resync request.

However, if the device response is delayed or fails (e.g due to
unstable connection and device getting out of tracking, hardware
errors, resource exhaustion etc.), the TLS module keeps logging and
incrementing, which can lead to a WARN() when rcd_delta exceeds the
threshold.

To address this, introduce tls_offload_rx_resync_async_request_cancel()
to explicitly cancel resync requests when a device response failure is
detected. Call this helper also as a final safeguard when rcd_delta
crosses its threshold, as reaching this point implies that earlier
cancellation did not occur.

Signed-off-by: Shahar Shitrit <shshitrit@nvidia.com>
Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Link: https://patch.msgid.link/1761508983-937977-3-git-send-email-tariqt@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-12-07 06:09:31 +09:00
Michal Luczaj
6743291514 vsock: Ignore signal/timeout on connect() if already established
[ Upstream commit 002541ef65 ]

During connect(), acting on a signal/timeout by disconnecting an already
established socket leads to several issues:

1. connect() invoking vsock_transport_cancel_pkt() ->
   virtio_transport_purge_skbs() may race with sendmsg() invoking
   virtio_transport_get_credit(). This results in a permanently elevated
   `vvs->bytes_unsent`. Which, in turn, confuses the SOCK_LINGER handling.

2. connect() resetting a connected socket's state may race with socket
   being placed in a sockmap. A disconnected socket remaining in a sockmap
   breaks sockmap's assumptions. And gives rise to WARNs.

3. connect() transitioning SS_CONNECTED -> SS_UNCONNECTED allows for a
   transport change/drop after TCP_ESTABLISHED. Which poses a problem for
   any simultaneous sendmsg() or connect() and may result in a
   use-after-free/null-ptr-deref.

Do not disconnect socket on signal/timeout. Keep the logic for unconnected
sockets: they don't linger, can't be placed in a sockmap, are rejected by
sendmsg().

[1]: https://lore.kernel.org/netdev/e07fd95c-9a38-4eea-9638-133e38c2ec9b@rbox.co/
[2]: https://lore.kernel.org/netdev/20250317-vsock-trans-signal-race-v4-0-fc8837f3f1d4@rbox.co/
[3]: https://lore.kernel.org/netdev/60f1b7db-3099-4f6a-875e-af9f6ef194f6@rbox.co/

Fixes: d021c34405 ("VSOCK: Introduce VM Sockets")
Signed-off-by: Michal Luczaj <mhal@rbox.co>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Link: https://patch.msgid.link/20251119-vsock-interrupted-connect-v2-1-70734cf1233f@rbox.co
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-12-07 06:09:31 +09:00
Ilya Maximets
f95bef5ba0 net: openvswitch: remove never-working support for setting nsh fields
[ Upstream commit dfe28c4167 ]

The validation of the set(nsh(...)) action is completely wrong.
It runs through the nsh_key_put_from_nlattr() function that is the
same function that validates NSH keys for the flow match and the
push_nsh() action.  However, the set(nsh(...)) has a very different
memory layout.  Nested attributes in there are doubled in size in
case of the masked set().  That makes proper validation impossible.

There is also confusion in the code between the 'masked' flag, that
says that the nested attributes are doubled in size containing both
the value and the mask, and the 'is_mask' that says that the value
we're parsing is the mask.  This is causing kernel crash on trying to
write into mask part of the match with SW_FLOW_KEY_PUT() during
validation, while validate_nsh() doesn't allocate any memory for it:

  BUG: kernel NULL pointer dereference, address: 0000000000000018
  #PF: supervisor read access in kernel mode
  #PF: error_code(0x0000) - not-present page
  PGD 1c2383067 P4D 1c2383067 PUD 20b703067 PMD 0
  Oops: Oops: 0000 [#1] SMP NOPTI
  CPU: 8 UID: 0 Kdump: loaded Not tainted 6.17.0-rc4+ #107 PREEMPT(voluntary)
  RIP: 0010:nsh_key_put_from_nlattr+0x19d/0x610 [openvswitch]
  Call Trace:
   <TASK>
   validate_nsh+0x60/0x90 [openvswitch]
   validate_set.constprop.0+0x270/0x3c0 [openvswitch]
   __ovs_nla_copy_actions+0x477/0x860 [openvswitch]
   ovs_nla_copy_actions+0x8d/0x100 [openvswitch]
   ovs_packet_cmd_execute+0x1cc/0x310 [openvswitch]
   genl_family_rcv_msg_doit+0xdb/0x130
   genl_family_rcv_msg+0x14b/0x220
   genl_rcv_msg+0x47/0xa0
   netlink_rcv_skb+0x53/0x100
   genl_rcv+0x24/0x40
   netlink_unicast+0x280/0x3b0
   netlink_sendmsg+0x1f7/0x430
   ____sys_sendmsg+0x36b/0x3a0
   ___sys_sendmsg+0x87/0xd0
   __sys_sendmsg+0x6d/0xd0
   do_syscall_64+0x7b/0x2c0
   entry_SYSCALL_64_after_hwframe+0x76/0x7e

The third issue with this process is that while trying to convert
the non-masked set into masked one, validate_set() copies and doubles
the size of the OVS_KEY_ATTR_NSH as if it didn't have any nested
attributes.  It should be copying each nested attribute and doubling
them in size independently.  And the process must be properly reversed
during the conversion back from masked to a non-masked variant during
the flow dump.

In the end, the only two outcomes of trying to use this action are
either validation failure or a kernel crash.  And if somehow someone
manages to install a flow with such an action, it will most definitely
not do what it is supposed to, since all the keys and the masks are
mixed up.

Fixing all the issues is a complex task as it requires re-writing
most of the validation code.

Given that and the fact that this functionality never worked since
introduction, let's just remove it altogether.  It's better to
re-introduce it later with a proper implementation instead of trying
to fix it in stable releases.

Fixes: b2d0f5d5dc ("openvswitch: enable NSH support")
Reported-by: Junvy Yang <zhuque@tencent.com>
Signed-off-by: Ilya Maximets <i.maximets@ovn.org>
Acked-by: Eelco Chaudron <echaudro@redhat.com>
Reviewed-by: Aaron Conole <aconole@redhat.com>
Link: https://patch.msgid.link/20251112112246.95064-1-i.maximets@ovn.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-12-07 06:09:31 +09:00
Eric Dumazet
99908e2d60 mptcp: fix race condition in mptcp_schedule_work()
commit 035bca3f01 upstream.

syzbot reported use-after-free in mptcp_schedule_work() [1]

Issue here is that mptcp_schedule_work() schedules a work,
then gets a refcount on sk->sk_refcnt if the work was scheduled.
This refcount will be released by mptcp_worker().

[A] if (schedule_work(...)) {
[B]     sock_hold(sk);
        return true;
    }

Problem is that mptcp_worker() can run immediately and complete before [B]

We need instead :

    sock_hold(sk);
    if (schedule_work(...))
        return true;
    sock_put(sk);

[1]
refcount_t: addition on 0; use-after-free.
 WARNING: CPU: 1 PID: 29 at lib/refcount.c:25 refcount_warn_saturate+0xfa/0x1d0 lib/refcount.c:25
Call Trace:
 <TASK>
 __refcount_add include/linux/refcount.h:-1 [inline]
  __refcount_inc include/linux/refcount.h:366 [inline]
  refcount_inc include/linux/refcount.h:383 [inline]
  sock_hold include/net/sock.h:816 [inline]
  mptcp_schedule_work+0x164/0x1a0 net/mptcp/protocol.c:943
  mptcp_tout_timer+0x21/0xa0 net/mptcp/protocol.c:2316
  call_timer_fn+0x17e/0x5f0 kernel/time/timer.c:1747
  expire_timers kernel/time/timer.c:1798 [inline]
  __run_timers kernel/time/timer.c:2372 [inline]
  __run_timer_base+0x648/0x970 kernel/time/timer.c:2384
  run_timer_base kernel/time/timer.c:2393 [inline]
  run_timer_softirq+0xb7/0x180 kernel/time/timer.c:2403
  handle_softirqs+0x22f/0x710 kernel/softirq.c:622
  __do_softirq kernel/softirq.c:656 [inline]
  run_ktimerd+0xcf/0x190 kernel/softirq.c:1138
  smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160
  kthread+0x711/0x8a0 kernel/kthread.c:463
  ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
  ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Cc: stable@vger.kernel.org
Fixes: 3b1d6210a9 ("mptcp: implement and use MPTCP-level retransmission")
Reported-by: syzbot+355158e7e301548a1424@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/6915b46f.050a0220.3565dc.0028.GAE@google.com/T/#u
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20251113103924.3737425-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-12-07 06:09:31 +09:00
Pedro Tammela
652b24f07b net/sched: act_connmark: handle errno on tcf_idr_check_alloc
commit fb07390463 upstream.

Smatch reports that 'ci' can be used uninitialized.
The current code ignores errno coming from tcf_idr_check_alloc, which
will lead to the incorrect usage of 'ci'. Handle the errno as it should.

Fixes: 288864effe ("net/sched: act_connmark: transition to percpu stats and rcu")
Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Pedro Tammela <pctammela@mojatatu.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-12-07 06:09:30 +09:00