==================================================================
BUG: KASAN: null-ptr-deref in instrument_atomic_read_write include/linux/instrumented.h:102 [inline]
BUG: KASAN: null-ptr-deref in atomic_try_cmpxchg_acquire include/linux/atomic/atomic-instrumented.h:541 [inline]
BUG: KASAN: null-ptr-deref in queued_spin_lock include/asm-generic/qspinlock.h:111 [inline]
BUG: KASAN: null-ptr-deref in do_raw_spin_lock include/linux/spinlock.h:187 [inline]
BUG: KASAN: null-ptr-deref in __raw_spin_lock include/linux/spinlock_api_smp.h:134 [inline]
BUG: KASAN: null-ptr-deref in _raw_spin_lock+0x87/0xf0 kernel/locking/spinlock.c:154
Write of size 4 at addr 00000000000000d4 by task syz.0.140/846
CPU: 1 PID: 846 Comm: syz.0.140 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
__dump_stack+0x21/0x24 lib/dump_stack.c:88
dump_stack_lvl+0x110/0x170 lib/dump_stack.c:106
print_report+0x3d/0x60 mm/kasan/report.c:423
kasan_report+0x122/0x150 mm/kasan/report.c:524
check_region_inline mm/kasan/generic.c:-1 [inline]
kasan_check_range+0x249/0x2a0 mm/kasan/generic.c:189
__kasan_check_write+0x14/0x20 mm/kasan/shadow.c:37
instrument_atomic_read_write include/linux/instrumented.h:102 [inline]
atomic_try_cmpxchg_acquire include/linux/atomic/atomic-instrumented.h:541 [inline]
queued_spin_lock include/asm-generic/qspinlock.h:111 [inline]
do_raw_spin_lock include/linux/spinlock.h:187 [inline]
__raw_spin_lock include/linux/spinlock_api_smp.h:134 [inline]
_raw_spin_lock+0x87/0xf0 kernel/locking/spinlock.c:154
spin_lock include/linux/spinlock.h:351 [inline]
mark_buffer_dirty_inode+0x116/0x300 fs/buffer.c:625
fat12_ent_put+0x1b8/0x2e0 fs/fat/fatent.c:173
fat_alloc_clusters+0x4cf/0xe30 fs/fat/fatent.c:503
fat_alloc_new_dir+0x164/0xb40 fs/fat/dir.c:1144
msdos_mkdir+0x2bb/0x500 fs/fat/namei_msdos.c:372
vfs_mkdir+0x39c/0x580 fs/namei.c:4113
do_mkdirat+0x174/0x4d0 fs/namei.c:4138
__do_sys_mkdir fs/namei.c:4158 [inline]
__se_sys_mkdir fs/namei.c:4156 [inline]
__x64_sys_mkdir+0x6e/0x80 fs/namei.c:4156
x64_sys_call+0x966/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:84
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f790d59ce59
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f790e4f9028 EFLAGS: 00000246 ORIG_RAX: 0000000000000053
RAX: ffffffffffffffda RBX: 00007f790d815fa0 RCX: 00007f790d59ce59
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00002000000000c0
RBP: 00007f790d632d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f790d816038 R14: 00007f790d815fa0 R15: 00007ffc5cad1248
==================================================================
BUG: kernel NULL pointer dereference, address: 00000000000000d4
#PF: supervisor write access in kernel mode
#PF: error_code(0x0002) - not-present page
PGD 13ad41067 P4D 13ad41067 PUD 0
Oops: 0002 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 846 Comm: syz.0.140 Tainted: G B syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:arch_atomic_try_cmpxchg arch/x86/include/asm/atomic.h:202 [inline]
RIP: 0010:atomic_try_cmpxchg_acquire include/linux/atomic/atomic-instrumented.h:543 [inline]
RIP: 0010:queued_spin_lock include/asm-generic/qspinlock.h:111 [inline]
RIP: 0010:do_raw_spin_lock include/linux/spinlock.h:187 [inline]
RIP: 0010:__raw_spin_lock include/linux/spinlock_api_smp.h:134 [inline]
RIP: 0010:_raw_spin_lock+0x9d/0xf0 kernel/locking/spinlock.c:154
Code: 44 24 20 00 00 00 00 48 89 df be 04 00 00 00 e8 a9 07 b6 fc 4c 89 f7 be 04 00 00 00 e8 9c 07 b6 fc 8b 44 24 20 b9 01 00 00 00 0f b1 0b 75 33 43 c6 44 27 04 f8 48 c7 04 24 0e 36 e0 45 4b c7
RSP: 0018:ffffc90000c577a0 EFLAGS: 00010297
RAX: 0000000000000000 RBX: 00000000000000d4 RCX: 0000000000000001
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffc90000c577c0
RBP: ffffc90000c57830 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff5200018aef8 R12: dffffc0000000000
R13: ffff888132cca1c0 R14: ffffc90000c577c0 R15: 1ffff9200018aef4
FS: 00007f790e4f96c0(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000000000d4 CR3: 000000011d68f000 CR4: 00000000003526a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
spin_lock include/linux/spinlock.h:351 [inline]
mark_buffer_dirty_inode+0x116/0x300 fs/buffer.c:625
fat12_ent_put+0x1b8/0x2e0 fs/fat/fatent.c:173
fat_alloc_clusters+0x4cf/0xe30 fs/fat/fatent.c:503
fat_alloc_new_dir+0x164/0xb40 fs/fat/dir.c:1144
msdos_mkdir+0x2bb/0x500 fs/fat/namei_msdos.c:372
vfs_mkdir+0x39c/0x580 fs/namei.c:4113
do_mkdirat+0x174/0x4d0 fs/namei.c:4138
__do_sys_mkdir fs/namei.c:4158 [inline]
__se_sys_mkdir fs/namei.c:4156 [inline]
__x64_sys_mkdir+0x6e/0x80 fs/namei.c:4156
x64_sys_call+0x966/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:84
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f790d59ce59
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f790e4f9028 EFLAGS: 00000246 ORIG_RAX: 0000000000000053
RAX: ffffffffffffffda RBX: 00007f790d815fa0 RCX: 00007f790d59ce59
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00002000000000c0
RBP: 00007f790d632d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f790d816038 R14: 00007f790d815fa0 R15: 00007ffc5cad1248
Modules linked in:
CR2: 00000000000000d4
---[ end trace 0000000000000000 ]---
RIP: 0010:arch_atomic_try_cmpxchg arch/x86/include/asm/atomic.h:202 [inline]
RIP: 0010:atomic_try_cmpxchg_acquire include/linux/atomic/atomic-instrumented.h:543 [inline]
RIP: 0010:queued_spin_lock include/asm-generic/qspinlock.h:111 [inline]
RIP: 0010:do_raw_spin_lock include/linux/spinlock.h:187 [inline]
RIP: 0010:__raw_spin_lock include/linux/spinlock_api_smp.h:134 [inline]
RIP: 0010:_raw_spin_lock+0x9d/0xf0 kernel/locking/spinlock.c:154
Code: 44 24 20 00 00 00 00 48 89 df be 04 00 00 00 e8 a9 07 b6 fc 4c 89 f7 be 04 00 00 00 e8 9c 07 b6 fc 8b 44 24 20 b9 01 00 00 00 0f b1 0b 75 33 43 c6 44 27 04 f8 48 c7 04 24 0e 36 e0 45 4b c7
RSP: 0018:ffffc90000c577a0 EFLAGS: 00010297
RAX: 0000000000000000 RBX: 00000000000000d4 RCX: 0000000000000001
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffc90000c577c0
RBP: ffffc90000c57830 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff5200018aef8 R12: dffffc0000000000
R13: ffff888132cca1c0 R14: ffffc90000c577c0 R15: 1ffff9200018aef4
FS: 00007f790e4f96c0(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000000000d4 CR3: 000000011d68f000 CR4: 00000000003526a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: 44 24 20 rex.R and $0x20,%al
3: 00 00 add %al,(%rax)
5: 00 00 add %al,(%rax)
7: 48 89 df mov %rbx,%rdi
a: be 04 00 00 00 mov $0x4,%esi
f: e8 a9 07 b6 fc call 0xfcb607bd
14: 4c 89 f7 mov %r14,%rdi
17: be 04 00 00 00 mov $0x4,%esi
1c: e8 9c 07 b6 fc call 0xfcb607bd
21: 8b 44 24 20 mov 0x20(%rsp),%eax
25: b9 01 00 00 00 mov $0x1,%ecx
* 2a: f0 0f b1 0b lock cmpxchg %ecx,(%rbx) <-- trapping instruction
2e: 75 33 jne 0x63
30: 43 c6 44 27 04 f8 movb $0xf8,0x4(%r15,%r12,1)
36: 48 c7 04 24 0e 36 e0 movq $0x45e0360e,(%rsp)
3d: 45
3e: 4b rex.WXB
3f: c7 .byte 0xc7