Re: [syzbot] [f2fs?] INFO: task hung in f2fs_release_file (3)

[syzbot <syzbot+4235e4d7b6fd75704528@syzkaller.appspotmail.com>]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
kernel BUG in ip6_pol_route

------------[ cut here ]------------
kernel BUG at net/ipv6/route.c:1473!
Oops: invalid opcode: 0000 [#1] SMP KASAN PTI
CPU: 1 UID: 0 PID: 31 Comm: kworker/1:0 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: wg-kex-wg0 wg_packet_handshake_receive_worker
RIP: 0010:rt6_make_pcpu_route net/ipv6/route.c:1473 [inline]
RIP: 0010:ip6_pol_route+0x117d/0x1180 net/ipv6/route.c:2305
Code: a7 f8 e9 f4 fa ff ff 89 d9 80 e1 07 80 c1 03 38 c1 0f 8c 03 fb ff ff 48 89 df e8 ce 64 a7 f8 e9 f6 fa ff ff e8 14 05 45 f8 90 <0f> 0b 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e
RSP: 0018:ffffc90000a5f0a0 EFLAGS: 00010293
RAX: ffffffff897b2cfc RBX: ffff888126e52000 RCX: ffff88801be9dac0
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90000a5f1b0 R08: ffffe8ffffd762cf R09: 1ffffd1ffffaec59
R10: dffffc0000000000 R11: fffff91ffffaec5a R12: ffff888035c06780
R13: ffffffff897b1ce2 R14: dffffc0000000000 R15: 0000607ed8f242c8
FS:  0000000000000000(0000) GS:ffff888126e52000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff9378335c0 CR3: 00000000379f0000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 pol_lookup_func include/net/ip6_fib.h:617 [inline]
 fib6_rule_lookup+0x1fc/0x6f0 net/ipv6/fib6_rules.c:120
 ip6_route_output_flags_noref net/ipv6/route.c:2684 [inline]
 ip6_route_output_flags+0x364/0x5d0 net/ipv6/route.c:2696
 ip6_dst_lookup_tail+0x299/0x1510 net/ipv6/ip6_output.c:1169
 ip6_dst_lookup_flow+0x47/0xe0 net/ipv6/ip6_output.c:1272
 send6+0x4ce/0x8d0 drivers/net/wireguard/socket.c:139
 wg_socket_send_skb_to_peer+0x128/0x200 drivers/net/wireguard/socket.c:178
 wg_packet_send_handshake_response+0x195/0x2d0 drivers/net/wireguard/send.c:103
 process_one_work kernel/workqueue.c:3257 [inline]
 process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:rt6_make_pcpu_route net/ipv6/route.c:1473 [inline]
RIP: 0010:ip6_pol_route+0x117d/0x1180 net/ipv6/route.c:2305
Code: a7 f8 e9 f4 fa ff ff 89 d9 80 e1 07 80 c1 03 38 c1 0f 8c 03 fb ff ff 48 89 df e8 ce 64 a7 f8 e9 f6 fa ff ff e8 14 05 45 f8 90 <0f> 0b 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e
RSP: 0018:ffffc90000a5f0a0 EFLAGS: 00010293
RAX: ffffffff897b2cfc RBX: ffff888126e52000 RCX: ffff88801be9dac0
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90000a5f1b0 R08: ffffe8ffffd762cf R09: 1ffffd1ffffaec59
R10: dffffc0000000000 R11: fffff91ffffaec5a R12: ffff888035c06780
R13: ffffffff897b1ce2 R14: dffffc0000000000 R15: 0000607ed8f242c8
FS:  0000000000000000(0000) GS:ffff888126e52000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055630cf94a38 CR3: 00000000273ba000 CR4: 00000000003526f0


Tested on:

commit:         3af870ae nfs/localio: fix regression due to out-of-ord..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=12e3fcc2580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=83a7cfc766b11a4f
dashboard link: https://syzkaller.appspot.com/bug?extid=4235e4d7b6fd75704528
compiler:       Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
patch:          https://syzkaller.appspot.com/x/patch.diff?x=17868992580000