loop4: detected capacity change from 0 to 2048
general protection fault, probably for non-canonical address 0xdffffc0000000004: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000020-0x0000000000000027]
CPU: 0 PID: 4411 Comm: syz-executor.4 Not tainted 6.7.0-syzkaller-12377-g9d1694dc91ce #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
RIP: 0010:__block_commit_write+0x5e/0x240 fs/buffer.c:2165
Code: d8 48 c1 e8 03 42 80 3c 38 00 74 08 48 89 df e8 08 90 e5 ff 4c 89 75 b0 48 8b 03 48 89 45 c8 48 8d 58 20 48 89 d8 48 c1 e8 03 <42> 80 3c 38 00 74 08 48 89 df e8 e3 8f e5 ff 8b 03 48 89 45 b8 45
RSP: 0018:ffffc90001fff748 EFLAGS: 00010202
RAX: 0000000000000004 RBX: 0000000000000020 RCX: ffff88811f328000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffea0004a06700
RBP: ffffc90001fff7a0 R08: ffffffff81df3992 R09: ffffea0004a06700
R10: ffffed10220aaf0c R11: ffffed10220aaf0c R12: ffffea0004a06700
R13: 000000000000000c R14: 0000000000000000 R15: dffffc0000000000
FS:  00007fe1790396c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020005280 CR3: 0000000111cb4000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 block_write_end+0xbd/0x150 fs/buffer.c:2251
 ext4_write_end+0x235/0x8a0 fs/ext4/inode.c:1287
 ext4_da_write_end+0xd4/0xb40 fs/ext4/inode.c:3020
 generic_perform_write+0x40c/0x610 mm/filemap.c:3939
 ext4_buffered_write_iter+0x31f/0x5e0 fs/ext4/file.c:299
 ext4_file_write_iter+0x199/0x16c0
 call_write_iter include/linux/fs.h:2085 [inline]
 new_sync_write fs/read_write.c:497 [inline]
 vfs_write+0xbae/0xf70 fs/read_write.c:590
 ksys_write+0x199/0x2c0 fs/read_write.c:643
 __do_sys_write fs/read_write.c:655 [inline]
 __se_sys_write fs/read_write.c:652 [inline]
 __x64_sys_write+0x7b/0x90 fs/read_write.c:652
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x55/0x120 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b
RIP: 0033:0x7fe17827cda9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fe1790390c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fe1783abf80 RCX: 00007fe17827cda9
RDX: 000000000000000c RSI: 0000000020000300 RDI: 0000000000000004
RBP: 00007fe1782c947a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007fe1783abf80 R15: 00007ffe70f14b98
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__block_commit_write+0x5e/0x240 fs/buffer.c:2165
Code: d8 48 c1 e8 03 42 80 3c 38 00 74 08 48 89 df e8 08 90 e5 ff 4c 89 75 b0 48 8b 03 48 89 45 c8 48 8d 58 20 48 89 d8 48 c1 e8 03 <42> 80 3c 38 00 74 08 48 89 df e8 e3 8f e5 ff 8b 03 48 89 45 b8 45
RSP: 0018:ffffc90001fff748 EFLAGS: 00010202
RAX: 0000000000000004 RBX: 0000000000000020 RCX: ffff88811f328000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffea0004a06700
RBP: ffffc90001fff7a0 R08: ffffffff81df3992 R09: ffffea0004a06700
R10: ffffed10220aaf0c R11: ffffed10220aaf0c R12: ffffea0004a06700
R13: 000000000000000c R14: 0000000000000000 R15: dffffc0000000000
FS:  00007fe1790396c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc1006f5000 CR3: 0000000111cb4000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	d8 48 c1             	fmuls  -0x3f(%rax)
   3:	e8 03 42 80 3c       	call   0x3c80420b
   8:	38 00                	cmp    %al,(%rax)
   a:	74 08                	je     0x14
   c:	48 89 df             	mov    %rbx,%rdi
   f:	e8 08 90 e5 ff       	call   0xffe5901c
  14:	4c 89 75 b0          	mov    %r14,-0x50(%rbp)
  18:	48 8b 03             	mov    (%rbx),%rax
  1b:	48 89 45 c8          	mov    %rax,-0x38(%rbp)
  1f:	48 8d 58 20          	lea    0x20(%rax),%rbx
  23:	48 89 d8             	mov    %rbx,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 80 3c 38 00       	cmpb   $0x0,(%rax,%r15,1) <-- trapping instruction
  2f:	74 08                	je     0x39
  31:	48 89 df             	mov    %rbx,%rdi
  34:	e8 e3 8f e5 ff       	call   0xffe5901c
  39:	8b 03                	mov    (%rbx),%eax
  3b:	48 89 45 b8          	mov    %rax,-0x48(%rbp)
  3f:	45                   	rex.RB