[syzbot] [netfilter?] WARNING in __nf_unregister_net_hook (9)

[syzbot <syzbot+78ac1e46d2966eb70fda@syzkaller.appspotmail.com>]

Hello,

syzbot found the following issue on:

HEAD commit:    9312ee76490d octeontx2-af: use unsigned int as iterator fo..
git tree:       net-next
console output: https://syzkaller.appspot.com/x/log.txt?x=114b88a2580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=4b71a7f00d74e4f3
dashboard link: https://syzkaller.appspot.com/bug?extid=78ac1e46d2966eb70fda
compiler:       Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/b381ecf9ad30/disk-9312ee76.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/ebd0e7846e92/vmlinux-9312ee76.xz
kernel image: https://storage.googleapis.com/syzbot-assets/b9c68d721e9c/bzImage-9312ee76.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+78ac1e46d2966eb70fda@syzkaller.appspotmail.com

x_tables: ip6_tables: mh match: only valid for protocol 135
------------[ cut here ]------------
hook not found, pf 10 num 1
WARNING: CPU: 0 PID: 7813 at net/netfilter/core.c:514 __nf_unregister_net_hook+0x30a/0x700 net/netfilter/core.c:514
Modules linked in:
CPU: 0 UID: 0 PID: 7813 Comm: syz.1.502 Not tainted 6.16.0-rc7-syzkaller-01904-g9312ee76490d #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:__nf_unregister_net_hook+0x30a/0x700 net/netfilter/core.c:514
Code: 58 59 ef 05 01 90 48 8b 44 24 10 0f b6 04 28 84 c0 0f 85 e3 03 00 00 41 8b 17 48 c7 c7 60 8f 98 8c 44 89 ee e8 07 46 e7 f7 90 <0f> 0b 90 90 e9 d8 01 00 00 e8 98 bf d3 01 89 c3 31 ff 89 c6 e8 1d
RSP: 0018:ffffc9000e8a7768 EFLAGS: 00010246
RAX: d399e8c7c2db4300 RBX: ffff8880688c2400 RCX: ffff88802c435a00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000002
RBP: dffffc0000000000 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffffbfff1bfaa6c R12: ffff888029a72440
R13: 000000000000000a R14: ffff888029a736c0 R15: ffffffff8c9a21fc
FS:  00007f5152aa66c0(0000) GS:ffff888125c12000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c34c54a CR3: 0000000027c74000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 nf_unregister_net_hook net/netfilter/core.c:-1 [inline]
 nf_unregister_net_hooks+0xcb/0x140 net/netfilter/core.c:610
 synproxy_tg6_destroy+0x58/0xb0 net/ipv6/netfilter/ip6t_SYNPROXY.c:94
 cleanup_entry+0x265/0x320 net/ipv6/netfilter/ip6_tables.c:669
 translate_table+0x1e5f/0x2040 net/ipv6/netfilter/ip6_tables.c:744
 do_replace net/ipv6/netfilter/ip6_tables.c:1154 [inline]
 do_ip6t_set_ctl+0x970/0xce0 net/ipv6/netfilter/ip6_tables.c:1644
 nf_setsockopt+0x26f/0x290 net/netfilter/nf_sockopt.c:101
 do_sock_setsockopt+0x179/0x1b0 net/socket.c:2344
 __sys_setsockopt net/socket.c:2369 [inline]
 __do_sys_setsockopt net/socket.c:2375 [inline]
 __se_sys_setsockopt net/socket.c:2372 [inline]
 __x64_sys_setsockopt+0x13f/0x1b0 net/socket.c:2372
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5151b8e9a9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f5152aa6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007f5151db6080 RCX: 00007f5151b8e9a9
RDX: 0000000000000040 RSI: 0000000000000029 RDI: 000000000000000d
RBP: 00007f5151c10d69 R08: 0000000000000470 R09: 0000000000000000
R10: 0000200000000480 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f5151db6080 R15: 00007ffc85b4e498
 </TASK>


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