lo_rw_aio(loop5) starting write with NULL file (already cleared?)
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000014: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x00000000000000a0-0x00000000000000a7]
CPU: 0 UID: 0 PID: 12834 Comm: kworker/u8:0 Tainted: G             L      syzkaller #0 PREEMPT_{RT,(full)} 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: loop5 loop_workfn
RIP: 0010:file_inode include/linux/fs.h:1353 [inline]
RIP: 0010:kiocb_start_write include/linux/fs.h:2756 [inline]
RIP: 0010:lo_rw_aio+0xd1d/0x1170 drivers/block/loop.c:412
Code: 34 fc 45 85 f6 0f 84 d2 00 00 00 43 80 7c 25 00 00 74 08 4c 89 ff e8 62 af 9d fc bb a0 00 00 00 49 03 1f 48 89 d8 48 c1 e8 03 <42> 80 3c 20 00 74 08 48 89 df e8 44 af 9d fc 48 8b 1b 48 83 c3 28
RSP: 0018:ffffc90003907680 EFLAGS: 00010206
RAX: 0000000000000014 RBX: 00000000000000a0 RCX: ffff88801ab48000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900039077f0 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffff52000720e81 R12: dffffc0000000000
R13: 1ffff11004d9e446 R14: 0000000000000001 R15: ffff888026cf2230
FS:  0000000000000000(0000) GS:ffff888125f1f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055557ca6aa88 CR3: 0000000029282000 CR4: 00000000003526f0
DR0: ffffffffffffffff DR1: 00000000000001f9 DR2: 0000000000000083
DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 do_req_filebacked drivers/block/loop.c:444 [inline]
 loop_handle_cmd drivers/block/loop.c:1940 [inline]
 loop_process_work+0x637/0x11b0 drivers/block/loop.c:1975
 process_one_work+0x98b/0x1630 kernel/workqueue.c:3306
 process_scheduled_works kernel/workqueue.c:3389 [inline]
 worker_thread+0xb49/0x1140 kernel/workqueue.c:3470
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:file_inode include/linux/fs.h:1353 [inline]
RIP: 0010:kiocb_start_write include/linux/fs.h:2756 [inline]
RIP: 0010:lo_rw_aio+0xd1d/0x1170 drivers/block/loop.c:412
Code: 34 fc 45 85 f6 0f 84 d2 00 00 00 43 80 7c 25 00 00 74 08 4c 89 ff e8 62 af 9d fc bb a0 00 00 00 49 03 1f 48 89 d8 48 c1 e8 03 <42> 80 3c 20 00 74 08 48 89 df e8 44 af 9d fc 48 8b 1b 48 83 c3 28
RSP: 0018:ffffc90003907680 EFLAGS: 00010206
RAX: 0000000000000014 RBX: 00000000000000a0 RCX: ffff88801ab48000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900039077f0 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffff52000720e81 R12: dffffc0000000000
R13: 1ffff11004d9e446 R14: 0000000000000001 R15: ffff888026cf2230
FS:  0000000000000000(0000) GS:ffff888125f1f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055557ca6aa88 CR3: 0000000029282000 CR4: 00000000003526f0
DR0: ffffffffffffffff DR1: 00000000000001f9 DR2: 0000000000000083
DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	34 fc                	xor    $0xfc,%al
   2:	45 85 f6             	test   %r14d,%r14d
   5:	0f 84 d2 00 00 00    	je     0xdd
   b:	43 80 7c 25 00 00    	cmpb   $0x0,0x0(%r13,%r12,1)
  11:	74 08                	je     0x1b
  13:	4c 89 ff             	mov    %r15,%rdi
  16:	e8 62 af 9d fc       	call   0xfc9daf7d
  1b:	bb a0 00 00 00       	mov    $0xa0,%ebx
  20:	49 03 1f             	add    (%r15),%rbx
  23:	48 89 d8             	mov    %rbx,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 80 3c 20 00       	cmpb   $0x0,(%rax,%r12,1) <-- trapping instruction
  2f:	74 08                	je     0x39
  31:	48 89 df             	mov    %rbx,%rdi
  34:	e8 44 af 9d fc       	call   0xfc9daf7d
  39:	48 8b 1b             	mov    (%rbx),%rbx
  3c:	48 83 c3 28          	add    $0x28,%rbx