BUG: kernel NULL pointer dereference, address: 0000000000000008
#PF: supervisor read access in kernel mode
#PF: error_code(0x0001) - permissions violation
PGD 8000000033064067 P4D 8000000033064067 PUD 50f51067 PMD 9106a067 PTE 5768e067
Oops: Oops: 0001 [#1] SMP KASAN PTI
CPU: 0 UID: 0 PID: 15437 Comm: syz.4.2084 Tainted: G U W L XTNJ syzkaller #0 PREEMPT(full)
Tainted: [U]=USER, [W]=WARN, [L]=SOFTLOCKUP, [X]=AUX, [T]=RANDSTRUCT, [N]=TEST, [J]=FWCTL
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/13/2026
RIP: 0010:qlink_to_cache mm/kasan/quarantine.c:131 [inline]
RIP: 0010:qlist_free_all+0x85/0xe0 mm/kasan/quarantine.c:176
Code: c1 53 48 ff 48 c1 e8 0c 48 c1 e0 06 48 03 05 82 53 7e 0b 48 8b 50 08 48 8d 4a ff 83 e2 01 48 0f 45 c1 80 78 33 f5 49 0f 45 c5 <48> 8b 68 08 eb 90 48 83 7d 60 00 75 a3 66 f7 45 20 04 02 75 9b 8b
RSP: 0000:ffffc90004cdf870 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffff888035db0001 RCX: ffffea0000a6df07
RDX: 0000000000000000 RSI: ffffffff81b80678 RDI: ffff888034275b80
RBP: 0000000000000000 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff888035db0001
R13: 0000000000000000 R14: ffffc90004cdf8a0 R15: ffff88803357d318
FS: 000055559447d500(0000) GS:ffff8881245e3000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000008 CR3: 0000000072494000 CR4: 00000000003526f0
Call Trace:
<TASK>
kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286
__kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:350
kasan_slab_alloc include/linux/kasan.h:253 [inline]
slab_post_alloc_hook mm/slub.c:4953 [inline]
slab_alloc_node mm/slub.c:5263 [inline]
kmem_cache_alloc_noprof+0x2ad/0x780 mm/slub.c:5270
new_handle fs/jbd2/transaction.c:457 [inline]
jbd2__journal_start+0x194/0x6a0 fs/jbd2/transaction.c:484
__ext4_journal_start_sb+0x32a/0x5c0 fs/ext4/ext4_jbd2.c:114
__ext4_journal_start fs/ext4/ext4_jbd2.h:242 [inline]
ext4_dirty_inode+0xa1/0x130 fs/ext4/inode.c:6499
__mark_inode_dirty+0x1ec/0x1560 fs/fs-writeback.c:2595
generic_update_time+0xcf/0xf0 fs/inode.c:2158
inode_update_time fs/inode.c:2171 [inline]
file_update_time_flags+0x401/0x510 fs/inode.c:2398
ext4_page_mkwrite+0x35b/0x1980 fs/ext4/inode.c:6668
do_page_mkwrite+0x17a/0x440 mm/memory.c:3531
do_shared_fault mm/memory.c:5834 [inline]
do_fault+0x3d7/0x1990 mm/memory.c:5896
do_pte_missing mm/memory.c:4404 [inline]
handle_pte_fault mm/memory.c:6276 [inline]
__handle_mm_fault+0x1807/0x2b50 mm/memory.c:6414
handle_mm_fault+0x36d/0xa20 mm/memory.c:6583
do_user_addr_fault+0x5a3/0x12f0 arch/x86/mm/fault.c:1334
handle_page_fault arch/x86/mm/fault.c:1474 [inline]
exc_page_fault+0x6f/0xd0 arch/x86/mm/fault.c:1527
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x7fd68866f6c0
Code: 83 e6 07 0f 85 19 01 00 00 be 08 00 00 00 4c 89 ff 83 c5 01 e8 11 95 fe ff 49 8b 47 40 41 83 47 30 08 48 8d 48 f8 49 89 4f 40 <48> 89 58 f8 49 83 c5 01 45 3b 6c 24 04 0f 82 fd fe ff ff 41 80 7f
RSP: 002b:00007fff7eff8350 EFLAGS: 00010202
RAX: 0000001b2f7b8000 RBX: ffffffff82894715 RCX: 0000001b2f7b7ff8
RDX: 0000001b2f224220 RSI: 0000000000000008 RDI: 00007fd689545720
RBP: 0000000000000052 R08: 00007fd688a00000 R09: 00007fd688a02000
R10: 0000000082894719 R11: 0000000000000013 R12: 00007fd688a16038
R13: 0000000000000058 R14: ffffffff82894fe4 R15: 00007fd689545720
</TASK>
Modules linked in:
CR2: 0000000000000008
---[ end trace 0000000000000000 ]---
RIP: 0010:qlink_to_cache mm/kasan/quarantine.c:131 [inline]
RIP: 0010:qlist_free_all+0x85/0xe0 mm/kasan/quarantine.c:176
Code: c1 53 48 ff 48 c1 e8 0c 48 c1 e0 06 48 03 05 82 53 7e 0b 48 8b 50 08 48 8d 4a ff 83 e2 01 48 0f 45 c1 80 78 33 f5 49 0f 45 c5 <48> 8b 68 08 eb 90 48 83 7d 60 00 75 a3 66 f7 45 20 04 02 75 9b 8b
RSP: 0000:ffffc90004cdf870 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffff888035db0001 RCX: ffffea0000a6df07
RDX: 0000000000000000 RSI: ffffffff81b80678 RDI: ffff888034275b80
RBP: 0000000000000000 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff888035db0001
R13: 0000000000000000 R14: ffffc90004cdf8a0 R15: ffff88803357d318
FS: 000055559447d500(0000) GS:ffff8881245e3000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000008 CR3: 0000000072494000 CR4: 00000000003526f0
----------------
Code disassembly (best guess):
0: c1 53 48 ff rcll $0xff,0x48(%rbx)
4: 48 c1 e8 0c shr $0xc,%rax
8: 48 c1 e0 06 shl $0x6,%rax
c: 48 03 05 82 53 7e 0b add 0xb7e5382(%rip),%rax # 0xb7e5395
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 c5 cmovne %r13,%rax
* 2a: 48 8b 68 08 mov 0x8(%rax),%rbp <-- trapping instruction
2e: eb 90 jmp 0xffffffc0
30: 48 83 7d 60 00 cmpq $0x0,0x60(%rbp)
35: 75 a3 jne 0xffffffda
37: 66 f7 45 20 04 02 testw $0x204,0x20(%rbp)
3d: 75 9b jne 0xffffffda
3f: 8b .byte 0x8b