BUG: kernel NULL pointer dereference, address: 0000000000000008
#PF: supervisor read access in kernel mode
#PF: error_code(0x0001) - permissions violation
PGD 8000000039dfb067 P4D 8000000039dfb067 PUD 28952067 PMD 28951067 PTE 405b4067
Oops: Oops: 0001 [#1] SMP KASAN PTI
CPU: 1 UID: 0 PID: 8442 Comm: syz.0.530 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:qlink_to_cache mm/kasan/quarantine.c:131 [inline]
RIP: 0010:qlist_move_cache+0x95/0xe0 mm/kasan/quarantine.c:303
Code: a1 05 47 ff 48 c1 e8 0c 48 c1 e0 06 48 03 05 02 66 af 0b 48 8b 50 08 48 8d 4a ff 83 e2 01 48 0f 45 c1 80 78 33 f5 49 0f 45 c4 <48> 8b 40 08 8b 50 30 48 39 c5 75 9a 48 83 3b 00 74 33 48 8b 43 08
RSP: 0018:ffffc90004817c88 EFLAGS: 00010006
RAX: 0000000000000000 RBX: ffffc90004817cc0 RCX: ffffffffffffffff
RDX: 0000000000000000 RSI: ffffffff816e55d8 RDI: 0000000000000007
RBP: ffff88805b4d3500 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: ffff88802f4f66b0 R12: 0000000000000000
R13: ffff888029b20001 R14: ffffffff9ac41be0 R15: 0000000000000000
FS:  0000555566738500(0000) GS:ffff8881249fc000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000008 CR3: 00000000223c2000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 kasan_quarantine_remove_cache+0x10a/0x180 mm/kasan/quarantine.c:370
 kmem_cache_destroy mm/slab_common.c:527 [inline]
 kmem_cache_destroy+0x6f/0x180 mm/slab_common.c:487
 mon_text_release+0x267/0x3d0 drivers/usb/mon/mon_text.c:677
 full_proxy_release+0xc0/0x140 fs/debugfs/file.c:427
 __fput+0x402/0xb70 fs/file_table.c:468
 task_work_run+0x150/0x240 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:44 [inline]
 exit_to_user_mode_loop+0xfb/0x540 kernel/entry/common.c:75
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
 do_syscall_64+0x4ee/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f63cb18f7c9
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:00007ffd76767b08 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007f63cb3e7da0 RCX: 00007f63cb18f7c9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f63cb3e7da0 R08: 0000000000000000 R09: 0000001e76767dff
R10: 000000000003fcac R11: 0000000000000246 R12: 0000000000042527
R13: 00007f63cb3e6540 R14: ffffffffffffffff R15: 00007ffd76767c20
 </TASK>
Modules linked in:
CR2: 0000000000000008
---[ end trace 0000000000000000 ]---
RIP: 0010:qlink_to_cache mm/kasan/quarantine.c:131 [inline]
RIP: 0010:qlist_move_cache+0x95/0xe0 mm/kasan/quarantine.c:303
Code: a1 05 47 ff 48 c1 e8 0c 48 c1 e0 06 48 03 05 02 66 af 0b 48 8b 50 08 48 8d 4a ff 83 e2 01 48 0f 45 c1 80 78 33 f5 49 0f 45 c4 <48> 8b 40 08 8b 50 30 48 39 c5 75 9a 48 83 3b 00 74 33 48 8b 43 08
RSP: 0018:ffffc90004817c88 EFLAGS: 00010006
RAX: 0000000000000000 RBX: ffffc90004817cc0 RCX: ffffffffffffffff
RDX: 0000000000000000 RSI: ffffffff816e55d8 RDI: 0000000000000007
RBP: ffff88805b4d3500 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: ffff88802f4f66b0 R12: 0000000000000000
R13: ffff888029b20001 R14: ffffffff9ac41be0 R15: 0000000000000000
FS:  0000555566738500(0000) GS:ffff8881249fc000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000008 CR3: 00000000223c2000 CR4: 00000000003526f0
----------------
Code disassembly (best guess):
   0:	a1 05 47 ff 48 c1 e8 	movabs 0x480ce8c148ff4705,%eax
   7:	0c 48
   9:	c1 e0 06             	shl    $0x6,%eax
   c:	48 03 05 02 66 af 0b 	add    0xbaf6602(%rip),%rax        # 0xbaf6615
  13:	48 8b 50 08          	mov    0x8(%rax),%rdx
  17:	48 8d 4a ff          	lea    -0x1(%rdx),%rcx
  1b:	83 e2 01             	and    $0x1,%edx
  1e:	48 0f 45 c1          	cmovne %rcx,%rax
  22:	80 78 33 f5          	cmpb   $0xf5,0x33(%rax)
  26:	49 0f 45 c4          	cmovne %r12,%rax
* 2a:	48 8b 40 08          	mov    0x8(%rax),%rax <-- trapping instruction
  2e:	8b 50 30             	mov    0x30(%rax),%edx
  31:	48 39 c5             	cmp    %rax,%rbp
  34:	75 9a                	jne    0xffffffd0
  36:	48 83 3b 00          	cmpq   $0x0,(%rbx)
  3a:	74 33                	je     0x6f
  3c:	48 8b 43 08          	mov    0x8(%rbx),%rax