Re: [syzbot] [net?] KASAN: slab-use-after-free Write in __xfrm_state_delete

[syzbot <syzbot+a25ee9d20d31e483ba7b@syzkaller.appspotmail.com>]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
BUG: corrupted list in __xfrm_state_delete

 non-paged memory
list_del corruption, ffff88805ae82758->next is LIST_POISON1 (dead000000000100)
------------[ cut here ]------------
kernel BUG at lib/list_debug.c:58!
Oops: invalid opcode: 0000 [#1] SMP KASAN PTI
CPU: 0 UID: 0 PID: 9 Comm: kworker/0:0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: events xfrm_state_gc_task
RIP: 0010:__list_del_entry_valid_or_report+0x10e/0x190 lib/list_debug.c:56
Code: 00 3a e3 8b 48 89 de e8 d0 79 57 fc 90 0f 0b 4c 89 e7 e8 f5 ff 31 fd 48 c7 c7 60 3a e3 8b 48 89 de 4c 89 e2 e8 b3 79 57 fc 90 <0f> 0b 4c 89 e7 e8 d8 ff 31 fd 48 c7 c7 c0 3a e3 8b 48 89 de 4c 89
RSP: 0018:ffffc900000e7900 EFLAGS: 00010246
RAX: 000000000000004e RBX: ffff88805ae82758 RCX: 684aa0a479b90900
RDX: 0000000000000000 RSI: 0000000000000202 RDI: 0000000000000000
RBP: dffffc0000000000 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffffbfff1bfa1ec R12: dead000000000100
R13: dffffc0000000000 R14: dead000000000100 R15: dead000000000122
FS:  0000000000000000(0000) GS:ffff888125c18000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000562559a41950 CR3: 000000007bf98000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 __list_del_entry_valid include/linux/list.h:124 [inline]
 __list_del_entry include/linux/list.h:215 [inline]
 list_del include/linux/list.h:229 [inline]
 __xfrm_state_delete+0xc2/0xca0 net/xfrm/xfrm_state.c:821
 xfrm_state_delete net/xfrm/xfrm_state.c:858 [inline]
 xfrm_state_gc_destroy net/xfrm/xfrm_state.c:619 [inline]
 xfrm_state_gc_task+0x54f/0x700 net/xfrm/xfrm_state.c:636
 process_one_work kernel/workqueue.c:3236 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
 kthread+0x70e/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__list_del_entry_valid_or_report+0x10e/0x190 lib/list_debug.c:56
Code: 00 3a e3 8b 48 89 de e8 d0 79 57 fc 90 0f 0b 4c 89 e7 e8 f5 ff 31 fd 48 c7 c7 60 3a e3 8b 48 89 de 4c 89 e2 e8 b3 79 57 fc 90 <0f> 0b 4c 89 e7 e8 d8 ff 31 fd 48 c7 c7 c0 3a e3 8b 48 89 de 4c 89
RSP: 0018:ffffc900000e7900 EFLAGS: 00010246
RAX: 000000000000004e RBX: ffff88805ae82758 RCX: 684aa0a479b90900
RDX: 0000000000000000 RSI: 0000000000000202 RDI: 0000000000000000
RBP: dffffc0000000000 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffffbfff1bfa1ec R12: dead000000000100
R13: dffffc0000000000 R14: dead000000000100 R15: dead000000000122
FS:  0000000000000000(0000) GS:ffff888125c18000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000562559a41950 CR3: 000000007bf98000 CR4: 00000000003526f0


Tested on:

commit:         b1c92cdf Merge branch 'net-wangxun-complete-ethtool-co..
git tree:       net-next
console output: https://syzkaller.appspot.com/x/log.txt?x=15a39862580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=67b99ceb67d33475
dashboard link: https://syzkaller.appspot.com/bug?extid=a25ee9d20d31e483ba7b
compiler:       Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7
patch:          https://syzkaller.appspot.com/x/patch.diff?x=10077a34580000