BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor instruction fetch in kernel mode
#PF: error_code(0x0010) - not-present page
PGD 1ea0a8067 P4D 1ea0a8067 PUD 0 
Oops: 0010 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 3772 Comm: syz.2.913 Tainted: G        W         5.4.292-syzkaller-00021-gcd8e74fa0fa3 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:0x0
Code: Bad RIP value.
RSP: 0018:ffff8881f6f09cf0 EFLAGS: 00010202
RAX: ffffffff8150a590 RBX: 0000000000000101 RCX: ffff8881eca6de80
RDX: 0000000000000101 RSI: 0000000000000000 RDI: ffff8881dce431c0
RBP: ffff8881f6f09d30 R08: 0000000000000004 R09: 0000000000000003
R10: ffffed103ede1398 R11: 1ffff1103ede1398 R12: 00000000ffffb5d0
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881dce431c0
FS:  00007f856b5c16c0(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 00000001d9877000 CR4: 00000000003406a0
DR0: 0000000000000000 DR1: 0000200000000300 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 call_timer_fn+0x3c/0x380 kernel/time/timer.c:1448
 expire_timers kernel/time/timer.c:1493 [inline]
 __run_timers+0x81d/0xb60 kernel/time/timer.c:1817
 run_timer_softirq+0x6a/0xf0 kernel/time/timer.c:1830
 __do_softirq+0x236/0x660 kernel/softirq.c:292
 invoke_softirq kernel/softirq.c:373 [inline]
 irq_exit+0x197/0x1c0 kernel/softirq.c:413
 exiting_irq arch/x86/include/asm/apic.h:539 [inline]
 smp_apic_timer_interrupt+0x11d/0x490 arch/x86/kernel/apic/apic.c:1161
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:834
 </IRQ>
RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x49/0x70 kernel/locking/spinlock.c:199
Code: 12 48 89 fb 48 c7 c7 b0 2d cb 85 e8 31 7f 62 fd 48 89 df 48 83 3d c6 33 a0 01 00 74 27 e8 93 37 1d fd 66 90 fb bf 01 00 00 00 <e8> 72 7a 16 fd 65 8b 05 87 93 d7 7b 85 c0 74 03 5b 5d c3 e8 7f 4d
RSP: 0018:ffff8881eee46d48 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000001 RBX: ffff8881e2ea0ca8 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001
RBP: ffff8881eee46d50 R08: dffffc0000000000 R09: fffffbfff0b8188d
R10: fffffbfff0b8188d R11: 1ffffffff0b8188c R12: ffffea000752a800
R13: ffff8881eee46de0 R14: 0000000000000001 R15: 0000000000000001
 spin_unlock_irq include/linux/spinlock.h:388 [inline]
 shmem_add_to_page_cache+0x7b3/0x9a0 mm/shmem.c:652
 shmem_getpage_gfp+0x10af/0x2370 mm/shmem.c:1890
 shmem_getpage mm/shmem.c:154 [inline]
 shmem_write_begin+0xce/0x1b0 mm/shmem.c:2447
 generic_perform_write+0x2b8/0x500 mm/filemap.c:3450
 __generic_file_write_iter+0x24b/0x480 mm/filemap.c:3579
 generic_file_write_iter+0x48d/0x620 mm/filemap.c:3611
 call_write_iter include/linux/fs.h:1991 [inline]
 new_sync_write fs/read_write.c:483 [inline]
 __vfs_write+0x480/0x5d0 fs/read_write.c:496
 __kernel_write+0xea/0x320 fs/read_write.c:515
 dump_emit+0x1c0/0x2c0 fs/coredump.c:838
 elf_core_dump+0x3465/0x3bd0 fs/binfmt_elf.c:2352
 do_coredump+0x1d8c/0x2ab0 fs/coredump.c:801
 get_signal+0xdb7/0x13d0 kernel/signal.c:2732
 do_signal+0xad/0xda0 arch/x86/kernel/signal.c:809
 exit_to_usermode_loop+0xc4/0x1b0 arch/x86/entry/common.c:159
 prepare_exit_to_usermode+0x18e/0x1f0 arch/x86/entry/common.c:194
 ret_from_intr+0x1c/0x1c
RIP: 0033:0x7f856cf9a971
Code: 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 83 c8 ff c3 66 2e 0f 1f
RSP: 002b:00000000fffffeb0 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007f856d1c2160 RCX: 00007f856cf9a969
RDX: 0000000000000000 RSI: 00000000fffffeb0 RDI: 0000000002000400
RBP: 00007f856d01cab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000001 R14: 00007f856d1c2160 R15: 00007ffcf6d3df58
Modules linked in:
CR2: 0000000000000000
---[ end trace c494807afd94e1cb ]---
RIP: 0010:0x0
Code: Bad RIP value.
RSP: 0018:ffff8881f6f09cf0 EFLAGS: 00010202
RAX: ffffffff8150a590 RBX: 0000000000000101 RCX: ffff8881eca6de80
RDX: 0000000000000101 RSI: 0000000000000000 RDI: ffff8881dce431c0
RBP: ffff8881f6f09d30 R08: 0000000000000004 R09: 0000000000000003
R10: ffffed103ede1398 R11: 1ffff1103ede1398 R12: 00000000ffffb5d0
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881dce431c0
FS:  00007f856b5c16c0(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 00000001d9877000 CR4: 00000000003406a0
DR0: 0000000000000000 DR1: 0000200000000300 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
----------------
Code disassembly (best guess):
   0:	12 48 89             	adc    -0x77(%rax),%cl
   3:	fb                   	sti
   4:	48 c7 c7 b0 2d cb 85 	mov    $0xffffffff85cb2db0,%rdi
   b:	e8 31 7f 62 fd       	call   0xfd627f41
  10:	48 89 df             	mov    %rbx,%rdi
  13:	48 83 3d c6 33 a0 01 	cmpq   $0x0,0x1a033c6(%rip)        # 0x1a033e1
  1a:	00
  1b:	74 27                	je     0x44
  1d:	e8 93 37 1d fd       	call   0xfd1d37b5
  22:	66 90                	xchg   %ax,%ax
  24:	fb                   	sti
  25:	bf 01 00 00 00       	mov    $0x1,%edi
* 2a:	e8 72 7a 16 fd       	call   0xfd167aa1 <-- trapping instruction
  2f:	65 8b 05 87 93 d7 7b 	mov    %gs:0x7bd79387(%rip),%eax        # 0x7bd793bd
  36:	85 c0                	test   %eax,%eax
  38:	74 03                	je     0x3d
  3a:	5b                   	pop    %rbx
  3b:	5d                   	pop    %rbp
  3c:	c3                   	ret
  3d:	e8                   	.byte 0xe8
  3e:	7f 4d                	jg     0x8d