[syzbot] [bridge?] WARNING in br_fill_linkxstats

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 627ac78f2741 ipv6: addrconf: bail out of dad_failure when ..
git tree: net-next
console output: https://syzkaller.appspot.com/x/log.txt?x=1074102e580000
kernel config: https://syzkaller.appspot.com/x/.config?x=f2b487b72ffad035
dashboard link: https://syzkaller.appspot.com/bug?extid=a35f9259d08f907c06e6
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/81fff4bdde96/disk-627ac78f.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/4b0352468dcd/vmlinux-627ac78f.xz
kernel image: https://storage.googleapis.com/syzbot-assets/6db18d47dfe4/bzImage-627ac78f.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+a35f92...@syzkaller.appspotmail.com

------------[ cut here ]------------
diff > ((u16)~0U)
WARNING: ./include/net/netlink.h:2265 at nla_nest_end include/net/netlink.h:2265 [inline], CPU#1: syz.2.5599/27626
WARNING: ./include/net/netlink.h:2265 at br_fill_linkxstats+0x9e7/0xae0 net/bridge/br_netlink.c:1910, CPU#1: syz.2.5599/27626
Modules linked in:
CPU: 1 UID: 0 PID: 27626 Comm: syz.2.5599 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:nla_nest_end include/net/netlink.h:2265 [inline]
RIP: 0010:br_fill_linkxstats+0x9e7/0xae0 net/bridge/br_netlink.c:1910
Code: b6 bd 08 48 3b 84 24 60 01 00 00 75 33 44 89 f0 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f 5d e9 50 8f 30 01 cc e8 0a 1b 49 f7 90 <0f> 0b 90 e9 bc fe ff ff e8 fc 1a 49 f7 90 0f 0b 90 e9 53 ff ff ff
RSP: 0018:ffffc9000d04f160 EFLAGS: 00010287
RAX: ffffffff8a7ca956 RBX: 0000000000013550 RCX: 0000000000080000
RDX: ffffc90010069000 RSI: 0000000000006616 RDI: 0000000000006617
RBP: ffffc9000d04f310 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000
R13: 1ffff92001a09e40 R14: 0000000000000000 R15: dffffc0000000000
FS: 00007f437e58c6c0(0000) GS:ffff88812537a000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7ecf36ab4c CR3: 000000003d060000 CR4: 00000000003526f0
Call Trace:
<TASK>
rtnl_fill_statsinfo+0x541/0x26f0 net/core/rtnetlink.c:6018
rtnl_stats_get+0x4b6/0x6d0 net/core/rtnetlink.c:6340
rtnetlink_rcv_msg+0x77e/0xbe0 net/core/rtnetlink.c:7018
netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2551
netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
netlink_unicast+0x75c/0x8e0 net/netlink/af_netlink.c:1345
netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1895
sock_sendmsg_nosec net/socket.c:787 [inline]
__sock_sendmsg net/socket.c:802 [inline]
____sys_sendmsg+0x972/0x9f0 net/socket.c:2698
___sys_sendmsg+0x2a5/0x360 net/socket.c:2752
__sys_sendmsg net/socket.c:2784 [inline]
__do_sys_sendmsg net/socket.c:2789 [inline]
__se_sys_sendmsg net/socket.c:2787 [inline]
__x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2787
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f437d79ce59
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f437e58c028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f437da16090 RCX: 00007f437d79ce59
RDX: 0000000000000000 RSI: 0000200000000040 RDI: 000000000000000a
RBP: 00007f437d832d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f437da16128 R14: 00007f437da16090 R15: 00007ffe687b3418
</TASK>


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