BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor instruction fetch in kernel mode
#PF: error_code(0x0010) - not-present page
PGD 1e1a17067 P4D 1e1a17067 PUD 0 
Oops: 0010 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 1656 Comm: syz.2.318 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:ffff8881f6e09cf0 EFLAGS: 00010206
RAX: ffffffff8150a590 RBX: 0000000000000100 RCX: ffff8881ebae4ec0
RDX: 0000000080000100 RSI: 0000000000000000 RDI: ffff8881d6feb1c0
RBP: ffff8881f6e09d30 R08: 0000000000000004 R09: 0000000000000003
R10: ffffed103edc1398 R11: 1ffff1103edc1398 R12: 00000000ffff9f28
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881d6feb1c0
FS:  00007fa8160056c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 00000001d7478000 CR4: 00000000003406b0
DR0: ffffffffffffffff DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff1 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:file_remove_privs+0x48/0x670 fs/inode.c:1925
Code: 04 25 28 00 00 00 48 89 84 24 c0 00 00 00 49 bd 00 00 00 00 00 fc ff df 48 c7 44 24 20 b3 8a b5 41 48 c7 44 24 28 5c 94 3d 85 <48> c7 44 24 30 e0 19 9a 81 4c 8d 7c 24 20 49 c1 ef 03 43 c7 04 2f
RSP: 0018:ffff8881e43c7120 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13
RAX: 6befb92521d92400 RBX: ffff8881eba2e000 RCX: ffff8881ebae4ec0
RDX: 0000000000000000 RSI: ffff8881e43c7410 RDI: ffff8881eba2e000
RBP: ffff8881e43c7228 R08: dffffc0000000000 R09: ffffed103d67fb9a
R10: ffffed103d67fb9a R11: 1ffff1103d67fb99 R12: ffffffff85d5f260
R13: dffffc0000000000 R14: ffff8881ebae56f0 R15: ffff8881eb3fdda0
 __generic_file_write_iter+0x163/0x480 mm/filemap.c:3525
 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: 0033:0x7fa81799c971
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:00002000000000c0 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007fa817bc3fa0 RCX: 00007fa81799c969
RDX: 0000200000000100 RSI: 00002000000000c0 RDI: 0000000041000000
RBP: 00007fa817a1eab1 R08: 0000200000000180 R09: 0000200000000180
R10: 0000200000000140 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fa817bc3fa0 R15: 00007ffcc595c8e8
Modules linked in:
CR2: 0000000000000000
---[ end trace 5402a6ea117f4abb ]---
RIP: 0010:0x0
Code: Bad RIP value.
RSP: 0018:ffff8881f6e09cf0 EFLAGS: 00010206
RAX: ffffffff8150a590 RBX: 0000000000000100 RCX: ffff8881ebae4ec0
RDX: 0000000080000100 RSI: 0000000000000000 RDI: ffff8881d6feb1c0
RBP: ffff8881f6e09d30 R08: 0000000000000004 R09: 0000000000000003
R10: ffffed103edc1398 R11: 1ffff1103edc1398 R12: 00000000ffff9f28
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881d6feb1c0
FS:  00007fa8160056c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 00000001d7478000 CR4: 00000000003406b0
DR0: ffffffffffffffff DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff1 DR7: 0000000000000600
----------------
Code disassembly (best guess):
   0:	04 25                	add    $0x25,%al
   2:	28 00                	sub    %al,(%rax)
   4:	00 00                	add    %al,(%rax)
   6:	48 89 84 24 c0 00 00 	mov    %rax,0xc0(%rsp)
   d:	00
   e:	49 bd 00 00 00 00 00 	movabs $0xdffffc0000000000,%r13
  15:	fc ff df
  18:	48 c7 44 24 20 b3 8a 	movq   $0x41b58ab3,0x20(%rsp)
  1f:	b5 41
  21:	48 c7 44 24 28 5c 94 	movq   $0xffffffff853d945c,0x28(%rsp)
  28:	3d 85
* 2a:	48 c7 44 24 30 e0 19 	movq   $0xffffffff819a19e0,0x30(%rsp) <-- trapping instruction
  31:	9a 81
  33:	4c 8d 7c 24 20       	lea    0x20(%rsp),%r15
  38:	49 c1 ef 03          	shr    $0x3,%r15
  3c:	43                   	rex.XB
  3d:	c7                   	.byte 0xc7
  3e:	04 2f                	add    $0x2f,%al