[v6.1] BUG: corrupted list in flow_block_cb_setup_simple

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 3594f306da12 Linux 6.1.147
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=11341782580000
kernel config: https://syzkaller.appspot.com/x/.config?x=30b8ca4950f83e04
dashboard link: https://syzkaller.appspot.com/bug?extid=8acff720883a383f572b
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/5b0395e2ec6c/disk-3594f306.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/c3ec331b7d5b/vmlinux-3594f306.xz
kernel image: https://storage.googleapis.com/syzbot-assets/bff42068e062/bzImage-3594f306.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+8acff7...@syzkaller.appspotmail.com

list_del corruption. prev->next should be ffff88802faaef00, but was ffffffff8d649400. (prev=ffffffff8d649400)
------------[ cut here ]------------
kernel BUG at lib/list_debug.c:61!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 12760 Comm: syz.5.1891 Not tainted 6.1.147-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:__list_del_entry_valid+0x10a/0x120 lib/list_debug.c:59
Code: e8 6b 56 00 06 0f 0b 48 c7 c7 60 f7 de 8a 48 89 de e8 5a 56 00 06 0f 0b 48 c7 c7 c0 f7 de 8a 48 89 de 4c 89 f9 e8 46 56 00 06 <0f> 0b 48 c7 c7 40 f8 de 8a 48 89 de 4c 89 f1 e8 32 56 00 06 0f 0b
RSP: 0018:ffffc90004a1eac8 EFLAGS: 00010246
RAX: 000000000000006d RBX: ffff88802faaef00 RCX: 1aa75e8947044100
RDX: ffffc9001361b000 RSI: 0000000000004083 RDI: 0000000000004084
RBP: 1ffff92000943d9a R08: dffffc0000000000 R09: fffff52000943ce9
R10: fffff52000943ce9 R11: 1ffff92000943ce8 R12: dffffc0000000000
R13: ffffc90004a1ecd0 R14: ffffffff8d649400 R15: ffffffff8d649400
FS: 00007f58f62166c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c3da5d4 CR3: 000000007e32d000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
__list_del_entry include/linux/list.h:134 [inline]
list_del include/linux/list.h:148 [inline]
flow_block_cb_setup_simple+0x629/0x740 net/core/flow_offload.c:355
nft_block_offload_cmd net/netfilter/nf_tables_offload.c:392 [inline]
nft_chain_offload_cmd+0x278/0x630 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_commit+0x4d2/0x18c0 net/netfilter/nf_tables_offload.c:584
nf_tables_commit+0x585/0x74e0 net/netfilter/nf_tables_api.c:9698
nfnetlink_rcv_batch net/netfilter/nfnetlink.c:569 [inline]
nfnetlink_rcv_skb_batch net/netfilter/nfnetlink.c:639 [inline]
nfnetlink_rcv+0x18b6/0x2170 net/netfilter/nfnetlink.c:657
netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
netlink_unicast+0x74d/0x8d0 net/netlink/af_netlink.c:1344
netlink_sendmsg+0x89e/0xbc0 net/netlink/af_netlink.c:1872
sock_sendmsg_nosec net/socket.c:718 [inline]
__sock_sendmsg net/socket.c:730 [inline]
____sys_sendmsg+0x59b/0x970 net/socket.c:2519
___sys_sendmsg+0x21c/0x290 net/socket.c:2573
__sys_sendmsg net/socket.c:2602 [inline]
__do_sys_sendmsg net/socket.c:2611 [inline]
__se_sys_sendmsg+0x19e/0x270 net/socket.c:2609
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f58f538e9a9
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:00007f58f6216038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f58f55b6080 RCX: 00007f58f538e9a9
RDX: 000000000000c050 RSI: 0000200000000cc0 RDI: 0000000000000007
RBP: 00007f58f5410d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f58f55b6080 R15: 00007ffdcea52958
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__list_del_entry_valid+0x10a/0x120 lib/list_debug.c:59
Code: e8 6b 56 00 06 0f 0b 48 c7 c7 60 f7 de 8a 48 89 de e8 5a 56 00 06 0f 0b 48 c7 c7 c0 f7 de 8a 48 89 de 4c 89 f9 e8 46 56 00 06 <0f> 0b 48 c7 c7 40 f8 de 8a 48 89 de 4c 89 f1 e8 32 56 00 06 0f 0b
RSP: 0018:ffffc90004a1eac8 EFLAGS: 00010246
RAX: 000000000000006d RBX: ffff88802faaef00 RCX: 1aa75e8947044100
RDX: ffffc9001361b000 RSI: 0000000000004083 RDI: 0000000000004084
RBP: 1ffff92000943d9a R08: dffffc0000000000 R09: fffff52000943ce9
R10: fffff52000943ce9 R11: 1ffff92000943ce8 R12: dffffc0000000000
R13: ffffc90004a1ecd0 R14: ffffffff8d649400 R15: ffffffff8d649400
FS: 00007f58f62166c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c3da5d4 CR3: 000000007e32d000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.