general protection fault in p9_client_destroy

Status: premoderation: reported on 2026/09/13 23:42
Reported-by: syzbot+b1c08e630e344746cc7e@syzkaller.appspotmail.com
First crash: 8d10h, last: 8d10h
Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KASAN: slab-use-after-free Read in p9_client_destroy v9fs 19 7 851d 864d 25/29 fixed on 2024/06/11 03:41

Sample crash report:
general protection fault, probably for non-canonical address 0xe0ffff8881205622: 0000 [#1] PREEMPT SMP KASAN
KASAN: maybe wild-memory-access in range [0x08001c440902b110-0x08001c440902b117]
CPU: 1 PID: 1495 Comm: syz-executor Tainted: G        W         syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:qlist_move_cache mm/kasan/quarantine.c:299 [inline]
RIP: 0010:kasan_quarantine_remove_cache+0xe6/0x1f0 mm/kasan/quarantine.c:348
Code: 00 00 80 7f 77 00 00 eb 21 8b 7f 18 49 89 10 48 89 51 08 48 c7 02 00 00 00 00 48 01 79 10 48 89 f2 48 85 f6 0f 84 68 ff ff ff <48> 8b 32 4c 89 d7 4c 39 ca 76 07 48 8b 3d 68 25 b8 04 48 01 d7 48
RSP: 0018:ffffc90000a37c08 EFLAGS: 00010086
RAX: 0000000000000a02 RBX: ffff88810fda2180 RCX: ffffffff87102050
RDX: e0ffff8881205622 RSI: e0ffff8881205622 RDI: 0000000000001100
RBP: ffffc90000a37c30 R08: ffff8881075aa000 R09: ffffffff7fffffff
R10: 0000777f80000000 R11: fffff52000146f6c R12: ffffea0000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 000000000000010e
FS:  0000555589a5a500(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555589a7d948 CR3: 000000012c55d000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 kasan_cache_shutdown+0x19/0x20 mm/kasan/generic.c:207
 shutdown_cache mm/slab_common.c:464 [inline]
 kmem_cache_destroy+0x48/0x140 mm/slab_common.c:512
 p9_client_destroy+0x3bc/0x410 net/9p/client.c:1112
 v9fs_session_close+0x4e/0x1c0 fs/9p/v9fs.c:501
 v9fs_kill_super+0x5c/0x90 fs/9p/vfs_super.c:226
 deactivate_locked_super+0xa0/0x100 fs/super.c:335
 deactivate_super+0xaf/0xe0 fs/super.c:366
 cleanup_mnt+0x44f/0x500 fs/namespace.c:1149
 __cleanup_mnt+0x19/0x20 fs/namespace.c:1156
 task_work_run+0x127/0x190 kernel/task_work.c:188
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop+0xd0/0xe0 kernel/entry/common.c:181
 exit_to_user_mode_prepare+0x87/0xd0 kernel/entry/common.c:214
 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
 syscall_exit_to_user_mode+0x1a/0x30 kernel/entry/common.c:307
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f8246667397
Code: a2 c7 05 5c 43 25 00 00 00 00 00 eb 96 e8 e1 12 00 00 90 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffcc0478298 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f8246667397
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffcc0478350
RBP: 00007ffcc0478350 R08: 00007ffcc0479350 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffcc04793e0
R13: 00007f82466fc48b R14: 000000000001e1b9 R15: 00007ffcc0479420
 </TASK>
Modules linked in:
---[ end trace c4673ad2eeda4ee4 ]---
RIP: 0010:qlist_move_cache mm/kasan/quarantine.c:299 [inline]
RIP: 0010:kasan_quarantine_remove_cache+0xe6/0x1f0 mm/kasan/quarantine.c:348
Code: 00 00 80 7f 77 00 00 eb 21 8b 7f 18 49 89 10 48 89 51 08 48 c7 02 00 00 00 00 48 01 79 10 48 89 f2 48 85 f6 0f 84 68 ff ff ff <48> 8b 32 4c 89 d7 4c 39 ca 76 07 48 8b 3d 68 25 b8 04 48 01 d7 48
RSP: 0018:ffffc90000a37c08 EFLAGS: 00010086
RAX: 0000000000000a02 RBX: ffff88810fda2180 RCX: ffffffff87102050
RDX: e0ffff8881205622 RSI: e0ffff8881205622 RDI: 0000000000001100
RBP: ffffc90000a37c30 R08: ffff8881075aa000 R09: ffffffff7fffffff
R10: 0000777f80000000 R11: fffff52000146f6c R12: ffffea0000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 000000000000010e
FS:  0000555589a5a500(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555589a7d948 CR3: 000000012c55d000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	00 00                	add    %al,(%rax)
   2:	80 7f 77 00          	cmpb   $0x0,0x77(%rdi)
   6:	00 eb                	add    %ch,%bl
   8:	21 8b 7f 18 49 89    	and    %ecx,-0x76b6e781(%rbx)
   e:	10 48 89             	adc    %cl,-0x77(%rax)
  11:	51                   	push   %rcx
  12:	08 48 c7             	or     %cl,-0x39(%rax)
  15:	02 00                	add    (%rax),%al
  17:	00 00                	add    %al,(%rax)
  19:	00 48 01             	add    %cl,0x1(%rax)
  1c:	79 10                	jns    0x2e
  1e:	48 89 f2             	mov    %rsi,%rdx
  21:	48 85 f6             	test   %rsi,%rsi
  24:	0f 84 68 ff ff ff    	je     0xffffff92
* 2a:	48 8b 32             	mov    (%rdx),%rsi <-- trapping instruction
  2d:	4c 89 d7             	mov    %r10,%rdi
  30:	4c 39 ca             	cmp    %r9,%rdx
  33:	76 07                	jbe    0x3c
  35:	48 8b 3d 68 25 b8 04 	mov    0x4b82568(%rip),%rdi        # 0x4b825a4
  3c:	48 01 d7             	add    %rdx,%rdi
  3f:	48                   	rex.W

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/09/13 23:41 android13-5.15-lts 5bfe2b8c1439 70a60e12 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in p9_client_destroy
* Struck through repros no longer work on HEAD.