[v5.15] BUG: corrupted list in flow_block_cb_setup_simple

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: aabd761612db Linux 5.15.215
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=109a1079580000
kernel config: https://syzkaller.appspot.com/x/.config?x=f161cbc9aef65db0
dashboard link: https://syzkaller.appspot.com/bug?extid=0ec2b1144c280b02e289
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=157c6299580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11769879580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/f636f56d3662/disk-aabd7616.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/f1a46620f40c/vmlinux-aabd7616.xz
kernel image: https://storage.googleapis.com/syzbot-assets/9b78bb48b022/bzImage-aabd7616.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+0ec2b1...@syzkaller.appspotmail.com

------------[ cut here ]------------
kernel BUG at lib/list_debug.c:61!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 4520 Comm: syz.0.144 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:__list_del_entry_valid+0x107/0x120 lib/list_debug.c:59
Code: 48 89 de e8 eb bc c8 05 0f 0b 48 c7 c7 40 46 7a 8a 48 89 de e8 da bc c8 05 0f 0b 48 c7 c7 a0 46 7a 8a 48 89 de e8 c9 bc c8 05 <0f> 0b 48 c7 c7 00 47 7a 8a 48 89 de e8 b8 bc c8 05 0f 0b 00 00 cc
RSP: 0018:ffffc9000345eb48 EFLAGS: 00010246
RAX: 0000000000000054 RBX: ffff888058a82900 RCX: 11bb8d31d7f7cc00
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: 1ffff9200068bdaa R08: ffff8880b9133d7f R09: 1ffff110172267af
R10: dffffc0000000000 R11: ffffed10172267b0 R12: dffffc0000000000
R13: ffffc9000345ed58 R14: ffffffff8cd87b80 R15: ffffffff8cd87b80
FS: 000055558f0ee500(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00001835f9898000 CR3: 0000000025242000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
__list_del_entry include/linux/list.h:132 [inline]
list_del include/linux/list.h:146 [inline]
flow_block_cb_setup_simple+0x62d/0x740 net/core/flow_offload.c:320
nft_block_offload_cmd net/netfilter/nf_tables_offload.c:392 [inline]
nft_chain_offload_cmd+0x287/0x670 net/netfilter/nf_tables_offload.c:446
nft_flow_block_chain net/netfilter/nf_tables_offload.c:466 [inline]
nft_flow_offload_chain net/netfilter/nf_tables_offload.c:505 [inline]
nft_flow_rule_offload_abort net/netfilter/nf_tables_offload.c:524 [inline]
nft_flow_rule_offload_commit+0x140d/0x19b0 net/netfilter/nf_tables_offload.c:612
nf_tables_commit+0x5ba/0x73e0 net/netfilter/nf_tables_api.c:9508
nfnetlink_rcv_batch net/netfilter/nfnetlink.c:564 [inline]
nfnetlink_rcv_skb_batch net/netfilter/nfnetlink.c:634 [inline]
nfnetlink_rcv+0x1aac/0x2450 net/netfilter/nfnetlink.c:652
netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline]
netlink_unicast+0x78f/0x940 net/netlink/af_netlink.c:1340
netlink_sendmsg+0x8ba/0xbe0 net/netlink/af_netlink.c:1919
sock_sendmsg_nosec net/socket.c:706 [inline]
__sock_sendmsg net/socket.c:718 [inline]
____sys_sendmsg+0x5be/0x8f0 net/socket.c:2446
___sys_sendmsg+0x236/0x2e0 net/socket.c:2500
__sys_sendmsg net/socket.c:2529 [inline]
__do_sys_sendmsg net/socket.c:2538 [inline]
__se_sys_sendmsg+0x1b7/0x2a0 net/socket.c:2536
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7feec9d9b0d9
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:00007ffc45e73aa8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007feeca022fa0 RCX: 00007feec9d9b0d9
RDX: 0000000000000000 RSI: 00002000000000c0 RDI: 0000000000000003
RBP: 00007feec9e32024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007feeca022fac R14: 00007feeca022fa0 R15: 00007feeca022fa0
</TASK>
Modules linked in:
---[ end trace 0db1934c9295157b ]---
RIP: 0010:__list_del_entry_valid+0x107/0x120 lib/list_debug.c:59
Code: 48 89 de e8 eb bc c8 05 0f 0b 48 c7 c7 40 46 7a 8a 48 89 de e8 da bc c8 05 0f 0b 48 c7 c7 a0 46 7a 8a 48 89 de e8 c9 bc c8 05 <0f> 0b 48 c7 c7 00 47 7a 8a 48 89 de e8 b8 bc c8 05 0f 0b 00 00 cc
RSP: 0018:ffffc9000345eb48 EFLAGS: 00010246

RAX: 0000000000000054 RBX: ffff888058a82900 RCX: 11bb8d31d7f7cc00
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: 1ffff9200068bdaa R08: ffff8880b9133d7f R09: 1ffff110172267af
R10: dffffc0000000000 R11: ffffed10172267b0 R12: dffffc0000000000
R13: ffffc9000345ed58 R14: ffffffff8cd87b80 R15: ffffffff8cd87b80
FS: 000055558f0ee500(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000000000c0 CR3: 0000000025242000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


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