Re: [syzbot] [net?] WARNING in xfrm_state_fini (4)

[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit:    8ce93aabbf75 bpf: Conditionally include dynptr copy kfuncs
git tree:       bpf
console output: https://syzkaller.appspot.com/x/log.txt?x=126853e2580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=67b63a24f3c26fca
dashboard link: https://syzkaller.appspot.com/bug?extid=999eb23467f83f9bf9bf
compiler:       Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=14218be2580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=17104258580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/4a42c2608bb7/disk-8ce93aab.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/84ea41a9a1bb/vmlinux-8ce93aab.xz
kernel image: https://storage.googleapis.com/syzbot-assets/94fb843154da/bzImage-8ce93aab.xz

The issue was bisected to:

commit b441cf3f8c4b8576639d20c8eb4aa32917602ecd
Author: Sabrina Dubroca <sd@xxxxxxxxxxxxxxx>
Date:   Fri Jul 4 14:54:33 2025 +0000

    xfrm: delete x->tunnel as we delete x

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=14b49734580000
final oops:     https://syzkaller.appspot.com/x/report.txt?x=16b49734580000
console output: https://syzkaller.appspot.com/x/log.txt?x=12b49734580000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+999eb23467f83f9bf9bf@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: b441cf3f8c4b ("xfrm: delete x->tunnel as we delete x")

------------[ cut here ]------------
WARNING: CPU: 0 PID: 36 at net/xfrm/xfrm_state.c:3306 xfrm_state_fini+0x26d/0x2f0 net/xfrm/xfrm_state.c:3306
Modules linked in:
CPU: 0 UID: 0 PID: 36 Comm: kworker/u8:2 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Workqueue: netns cleanup_net
RIP: 0010:xfrm_state_fini+0x26d/0x2f0 net/xfrm/xfrm_state.c:3306
Code: c1 e8 03 42 80 3c 28 00 74 08 48 89 df e8 bb ca 3a f8 48 8b 3b 5b 41 5c 41 5d 41 5e 41 5f 5d e9 09 b8 1a f8 e8 84 15 d5 f7 90 <0f> 0b 90 e9 fd fd ff ff e8 76 15 d5 f7 90 0f 0b 90 e9 60 fe ff ff
RSP: 0018:ffffc90000ac7878 EFLAGS: 00010293
RAX: ffffffff89eaee7c RBX: ffff888027f82480 RCX: ffff888143ab9e40
RDX: 0000000000000000 RSI: ffffffff8d70bc9a RDI: ffffffff8bbf0460
RBP: ffffc90000ac7990 R08: ffffffff8f7cd477 R09: 1ffffffff1ef9a8e
R10: dffffc0000000000 R11: fffffbfff1ef9a8f R12: ffffffff8f3c6100
R13: 1ffff92000158f3c R14: ffff888027f83940 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff88812613e000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa946164f98 CR3: 0000000030606000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 xfrm_net_exit+0x2d/0x70 net/xfrm/xfrm_policy.c:4354
 ops_exit_list net/core/net_namespace.c:199 [inline]
 ops_undo_list+0x49a/0x990 net/core/net_namespace.c:252
 cleanup_net+0x4d8/0x820 net/core/net_namespace.c:695
 process_one_work kernel/workqueue.c:3263 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>


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