BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor instruction fetch in kernel mode
#PF: error_code(0x0010) - not-present page
PGD 1ef322067 P4D 1ef322067 PUD 0 
Oops: 0010 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 1049 Comm: syz-executor.2 Not tainted 5.4.274-syzkaller-00002-g6f97bd951d82 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
RIP: 0010:0x0
Code: Bad RIP value.
RSP: 0018:ffff8881f6f09d18 EFLAGS: 00010206
RAX: ffffffff8154d7aa RBX: 0000000000000100 RCX: ffff8881d3402f40
RDX: 0000000000000100 RSI: 0000000000000000 RDI: ffff8881da6cb1c0
RBP: ffff8881f6f09ec8 R08: ffffffff8154d3ee R09: 0000000000000003
R10: ffffffffffffffff R11: dffffc0000000001 R12: 00000000ffffaf90
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881da6cb1c0
FS:  0000555556acc480(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 00000001eb2ba000 CR4: 00000000003406a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
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:538 [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:ext4_mb_new_blocks+0x396/0x2d10 fs/ext4/mballoc.c:4561
Code: 84 c0 0f 85 bd 1d 00 00 c7 02 f4 ff ff ff 31 c0 48 89 44 24 20 e9 8a 18 00 00 e8 05 b6 99 ff e9 25 03 00 00 31 ff 89 74 24 34 <e8> e5 b8 99 ff 83 7c 24 34 00 0f 84 0a 03 00 00 48 8b 84 24 90 00
RSP: 0018:ffff8881ea927400 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000000 RBX: ffff8881ee062000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffffff81ca848e R09: ffffed103dc0c413
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff8881ea927788
R13: dffffc0000000000 R14: 1ffff1103d524ef1 R15: ffff8881ea9277b0
 ext4_ext_map_blocks+0x1e70/0x7450 fs/ext4/extents.c:4511
 ext4_map_blocks+0xa2f/0x1ba0 fs/ext4/inode.c:661
 ext4_getblk+0x112/0x540 fs/ext4/inode.c:985
 ext4_bread+0x89/0x390 fs/ext4/inode.c:1035
 ext4_append+0x297/0x4d0 fs/ext4/namei.c:83
 ext4_init_new_dir fs/ext4/namei.c:2892 [inline]
 ext4_mkdir+0x777/0x1520 fs/ext4/namei.c:2937
 vfs_mkdir+0x4b9/0x690 fs/namei.c:3965
 do_mkdirat+0x1a6/0x2c0 fs/namei.c:3987
 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x5c/0xc1
RIP: 0033:0x7f3e81d819a7
Code: 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 02 01 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffec532c758 EFLAGS: 00000202 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007ffec532c7d0 RCX: 00007f3e81d819a7
RDX: 00000000000001ff RSI: 00007ffec532c7d0 RDI: 00000000ffffff9c
RBP: 00007ffec532c7ac R08: 0000000000000004 R09: 00007ffec532c4f6
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000032
R13: 00000000000175ce R14: 00000000000175bd R15: 0000000000000003
Modules linked in:
CR2: 0000000000000000
---[ end trace d4a2f1976f995e98 ]---
RIP: 0010:0x0
Code: Bad RIP value.
RSP: 0018:ffff8881f6f09d18 EFLAGS: 00010206
RAX: ffffffff8154d7aa RBX: 0000000000000100 RCX: ffff8881d3402f40
RDX: 0000000000000100 RSI: 0000000000000000 RDI: ffff8881da6cb1c0
RBP: ffff8881f6f09ec8 R08: ffffffff8154d3ee R09: 0000000000000003
R10: ffffffffffffffff R11: dffffc0000000001 R12: 00000000ffffaf90
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881da6cb1c0
FS:  0000555556acc480(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 00000001eb2ba000 CR4: 00000000003406a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	84 c0                	test   %al,%al
   2:	0f 85 bd 1d 00 00    	jne    0x1dc5
   8:	c7 02 f4 ff ff ff    	movl   $0xfffffff4,(%rdx)
   e:	31 c0                	xor    %eax,%eax
  10:	48 89 44 24 20       	mov    %rax,0x20(%rsp)
  15:	e9 8a 18 00 00       	jmp    0x18a4
  1a:	e8 05 b6 99 ff       	call   0xff99b624
  1f:	e9 25 03 00 00       	jmp    0x349
  24:	31 ff                	xor    %edi,%edi
  26:	89 74 24 34          	mov    %esi,0x34(%rsp)
* 2a:	e8 e5 b8 99 ff       	call   0xff99b914 <-- trapping instruction
  2f:	83 7c 24 34 00       	cmpl   $0x0,0x34(%rsp)
  34:	0f 84 0a 03 00 00    	je     0x344
  3a:	48                   	rex.W
  3b:	8b                   	.byte 0x8b
  3c:	84 24 90             	test   %ah,(%rax,%rdx,4)