RBP: 00007fddc0e21ff1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fff671e8a3f R14: 00007fddbff3e300 R15: 0000000000022000
---[ end trace 8d4e5fe33cce5479 ]---
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 27723 Comm: syz-executor.1 Tainted: G        W         5.4.147-syzkaller-00015-g5b673be0c6b0 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:strlen+0x27/0x60 lib/string.c:551
Code: 0f 1f 00 41 57 41 56 53 49 89 fe 49 bf 00 00 00 00 00 fc ff df 48 89 f8 66 66 2e 0f 1f 84 00 00 00 00 00 48 89 c3 48 c1 e8 03 <42> 0f b6 04 38 84 c0 75 0b 48 8d 43 01 80 3b 00 75 e7 eb 13 89 d9
RSP: 0018:ffff8881e940fcd0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000200001
RDX: 0000000000200000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffffff81b1b57b R09: 000000000000ffff
R10: ffffc90000f4b000 R11: 0000000000000000 R12: ffff8881f18e4ed8
R13: 0000000000000000 R14: 0000000000000000 R15: dffffc0000000000
FS:  00007fddbff3e700(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2ed34000 CR3: 00000001cf1b4000 CR4: 00000000003406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 kernfs_name_hash fs/kernfs/dir.c:302 [inline]
 kernfs_find_ns+0x83/0x430 fs/kernfs/dir.c:847
 kernfs_remove_by_name_ns+0x32/0x90 fs/kernfs/dir.c:1510
 del_gendisk+0x93d/0xb70 block/genhd.c:833
 loop_remove drivers/block/loop.c:2189 [inline]
 loop_control_ioctl+0x563/0x680 drivers/block/loop.c:2288
 do_vfs_ioctl+0x6fb/0x15b0 fs/ioctl.c:47
 ksys_ioctl fs/ioctl.c:742 [inline]
 __do_sys_ioctl fs/ioctl.c:749 [inline]
 __se_sys_ioctl fs/ioctl.c:747 [inline]
 __x64_sys_ioctl+0xd4/0x110 fs/ioctl.c:747
 do_syscall_64+0xcb/0x1e0 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7fddc0dc7e99
Code: ff ff c3 66 2e 0f 1f 84 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 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fddbff3e168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fddc0edaf60 RCX: 00007fddc0dc7e99
RDX: 0000000000000000 RSI: 0000000000004c81 RDI: 0000000000000003
RBP: 00007fddc0e21ff1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fff671e8a3f R14: 00007fddbff3e300 R15: 0000000000022000
Modules linked in:
---[ end trace 8d4e5fe33cce547a ]---
RIP: 0010:strlen+0x27/0x60 lib/string.c:551
Code: 0f 1f 00 41 57 41 56 53 49 89 fe 49 bf 00 00 00 00 00 fc ff df 48 89 f8 66 66 2e 0f 1f 84 00 00 00 00 00 48 89 c3 48 c1 e8 03 <42> 0f b6 04 38 84 c0 75 0b 48 8d 43 01 80 3b 00 75 e7 eb 13 89 d9
RSP: 0018:ffff8881e940fcd0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000200001
RDX: 0000000000200000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffffff81b1b57b R09: 000000000000ffff
R10: ffffc90000f4b000 R11: 0000000000000000 R12: ffff8881f18e4ed8
R13: 0000000000000000 R14: 0000000000000000 R15: dffffc0000000000
FS:  00007fddbff3e700(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2ed34000 CR3: 00000001cf1b4000 CR4: 00000000003406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	0f 1f 00             	nopl   (%rax)
   3:	41 57                	push   %r15
   5:	41 56                	push   %r14
   7:	53                   	push   %rbx
   8:	49 89 fe             	mov    %rdi,%r14
   b:	49 bf 00 00 00 00 00 	movabs $0xdffffc0000000000,%r15
  12:	fc ff df
  15:	48 89 f8             	mov    %rdi,%rax
  18:	66 66 2e 0f 1f 84 00 	data16 nopw %cs:0x0(%rax,%rax,1)
  1f:	00 00 00 00
  23:	48 89 c3             	mov    %rax,%rbx
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 0f b6 04 38       	movzbl (%rax,%r15,1),%eax <-- trapping instruction
  2f:	84 c0                	test   %al,%al
  31:	75 0b                	jne    0x3e
  33:	48 8d 43 01          	lea    0x1(%rbx),%rax
  37:	80 3b 00             	cmpb   $0x0,(%rbx)
  3a:	75 e7                	jne    0x23
  3c:	eb 13                	jmp    0x51
  3e:	89 d9                	mov    %ebx,%ecx