syzbot

BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor instruction fetch in kernel mode
#PF: error_code(0x0010) - not-present page
PGD 0 P4D 0 
Oops: 0010 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 162 Comm: udevd Not tainted 5.4.276-syzkaller-00021-g58de09405d1e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
RIP: 0010:0x0
Code: Bad RIP value.
RSP: 0018:ffff8881f6e09d18 EFLAGS: 00010206
RAX: ffffffff8154d48a RBX: 0000000000000100 RCX: ffff8881ed4e0fc0
RDX: 0000000080000100 RSI: 0000000000000000 RDI: ffff8881defc31c0
RBP: ffff8881f6e09ec8 R08: ffffffff8154d0ce R09: 0000000000000003
R10: ffffffffffffffff R11: dffffc0000000001 R12: 00000000ffffa8f0
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881defc31c0
FS:  00007f9c30d61c80(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 00000001ed5d2000 CR4: 00000000003406b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 call_timer_fn+0x36/0x390 kernel/time/timer.c:1448
 expire_timers kernel/time/timer.c:1493 [inline]
 __run_timers+0x879/0xbe0 kernel/time/timer.c:1817
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1830
 __do_softirq+0x23b/0x6b7 kernel/softirq.c:292
 invoke_softirq kernel/softirq.c:373 [inline]
 irq_exit+0x195/0x1c0 kernel/softirq.c:413
 exiting_irq arch/x86/include/asm/apic.h:539 [inline]
 smp_apic_timer_interrupt+0x11a/0x460 arch/x86/kernel/apic/apic.c:1149
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:834
 </IRQ>
RIP: 0010:__kernel_text_address+0x1/0x100 kernel/extable.c:102
Code: 2e 0f 1f 84 00 00 00 00 00 48 c7 c0 00 00 e0 85 48 39 c7 0f 93 c0 48 c7 c1 40 71 4c 86 48 39 cf 0f 92 c1 20 c1 0f b6 c1 c3 55 <41> 56 53 48 89 fb 48 c7 c0 00 00 00 81 bd 01 00 00 00 48 39 c7 72
RSP: 0018:ffff8881ec957730 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000000 RBX: ffff8881ec9577a8 RCX: c627cccda09c9900
RDX: dffffc0000000000 RSI: ffff8881ec9572e0 RDI: ffffffff8153af48
RBP: ffff8881ec9577f0 R08: dffffc0000000000 R09: ffff8881ec9577b0
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff8881ed4e0fc0
R13: ffffffff8153aff0 R14: dffffc0000000000 R15: 1ffff1103d92aef5
 unwind_get_return_address+0x49/0x80 arch/x86/kernel/unwind_orc.c:313
 arch_stack_walk+0xf5/0x140 arch/x86/kernel/stacktrace.c:26
 stack_trace_save+0x118/0x1c0 kernel/stacktrace.c:123
 save_stack mm/kasan/common.c:70 [inline]
 set_track mm/kasan/common.c:78 [inline]
 __kasan_kmalloc+0x171/0x210 mm/kasan/common.c:529
 slab_post_alloc_hook mm/slab.h:584 [inline]
 slab_alloc_node mm/slub.c:2829 [inline]
 slab_alloc mm/slub.c:2837 [inline]
 kmem_cache_alloc+0xd9/0x250 mm/slub.c:2842
 getname_flags+0xb8/0x4e0 fs/namei.c:141
 user_path_at_empty+0x28/0x50 fs/namei.c:2703
 user_path_at include/linux/namei.h:49 [inline]
 vfs_statx+0x115/0x210 fs/stat.c:187
 vfs_fstatat include/linux/fs.h:3380 [inline]
 __do_sys_newfstatat fs/stat.c:367 [inline]
 __se_sys_newfstatat+0xce/0x770 fs/stat.c:361
 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x5c/0xc1
RIP: 0033:0x7f9c30e8c5f4
Code: 64 c7 00 09 00 00 00 83 c8 ff c3 48 89 f2 b9 00 01 00 00 48 89 fe bf 9c ff ff ff e9 00 00 00 00 41 89 ca b8 06 01 00 00 0f 05 <45> 31 c0 3d 00 f0 ff ff 76 10 48 8b 15 03 a8 0d 00 f7 d8 41 83 c8
RSP: 002b:00007ffd3b7e6268 EFLAGS: 00000246 ORIG_RAX: 0000000000000106
RAX: ffffffffffffffda RBX: 00007ffd3b7e7c08 RCX: 00007f9c30e8c5f4
RDX: 00007ffd3b7e6278 RSI: 00007ffd3b7e6708 RDI: 00000000ffffff9c
RBP: 00007ffd3b7e6308 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffd3b7e6708
R13: 00007ffd3b7e6278 R14: 00005568aeb482c0 R15: 0000000000000000
Modules linked in:
CR2: 0000000000000000
---[ end trace 1456979f2a8a2d2a ]---
RIP: 0010:0x0
Code: Bad RIP value.
RSP: 0018:ffff8881f6e09d18 EFLAGS: 00010206
RAX: ffffffff8154d48a RBX: 0000000000000100 RCX: ffff8881ed4e0fc0
RDX: 0000000080000100 RSI: 0000000000000000 RDI: ffff8881defc31c0
RBP: ffff8881f6e09ec8 R08: ffffffff8154d0ce R09: 0000000000000003
R10: ffffffffffffffff R11: dffffc0000000001 R12: 00000000ffffa8f0
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881defc31c0
FS:  00007f9c30d61c80(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 00000001ed5d2000 CR4: 00000000003406b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
----------------
Code disassembly (best guess):
   0:	2e 0f 1f 84 00 00 00 	cs nopl 0x0(%rax,%rax,1)
   7:	00 00
   9:	48 c7 c0 00 00 e0 85 	mov    $0xffffffff85e00000,%rax
  10:	48 39 c7             	cmp    %rax,%rdi
  13:	0f 93 c0             	setae  %al
  16:	48 c7 c1 40 71 4c 86 	mov    $0xffffffff864c7140,%rcx
  1d:	48 39 cf             	cmp    %rcx,%rdi
  20:	0f 92 c1             	setb   %cl
  23:	20 c1                	and    %al,%cl
  25:	0f b6 c1             	movzbl %cl,%eax
  28:	c3                   	ret
  29:	55                   	push   %rbp
* 2a:	41 56                	push   %r14 <-- trapping instruction
  2c:	53                   	push   %rbx
  2d:	48 89 fb             	mov    %rdi,%rbx
  30:	48 c7 c0 00 00 00 81 	mov    $0xffffffff81000000,%rax
  37:	bd 01 00 00 00       	mov    $0x1,%ebp
  3c:	48 39 c7             	cmp    %rax,%rdi
  3f:	72                   	.byte 0x72