RBP: 00007fa8d618a161 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffe3e77a6ef R14: 00007fa8d52a6300 R15: 0000000000022000
---[ end trace 8faa189455becb1a ]---
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: 0 PID: 26950 Comm: syz-executor.2 Tainted: G        W         5.4.197-syzkaller-00110-g2bde2e268ec7 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022
RIP: 0010:strlen+0x2a/0x60 lib/string.c:551
Code: 41 57 41 56 41 54 53 49 89 fe 48 c7 c0 ff ff ff ff 49 bf 00 00 00 00 00 fc ff df 48 89 fb 66 90 49 89 c4 48 89 d8 48 c1 e8 03 <42> 0f b6 04 38 84 c0 75 12 48 ff c3 49 8d 44 24 01 43 80 7c 26 01
RSP: 0018:ffff8881c798fc70 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff8881e4149f80
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffffff81b05ef9 R09: ffffed1038f31f9b
R10: ffffed1038f31f9b R11: 1ffff11038f31f9a R12: ffffffffffffffff
R13: 0000000000000000 R14: 0000000000000000 R15: dffffc0000000000
FS:  00007fa8d52a6700(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffe5e21a338 CR3: 00000001ed171000 CR4: 00000000003406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 kernfs_name_hash+0x1e/0x220 fs/kernfs/dir.c:302
 kernfs_find_ns+0x6b/0x260 fs/kernfs/dir.c:847
 kernfs_remove_by_name_ns+0x32/0x90 fs/kernfs/dir.c:1510
 del_gendisk+0x92d/0xb60 block/genhd.c:833
 loop_remove+0x42/0xa0 drivers/block/loop.c:2189
 loop_control_ioctl+0x547/0x600 drivers/block/loop.c:2288
 do_vfs_ioctl+0x6d1/0x15b0 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/0x1c0 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7fa8d6130209
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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fa8d52a6168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fa8d6242f60 RCX: 00007fa8d6130209
RDX: 0000000000000000 RSI: 0000000000004c81 RDI: 0000000000000003
RBP: 00007fa8d618a161 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffe3e77a6ef R14: 00007fa8d52a6300 R15: 0000000000022000
Modules linked in:
---[ end trace 8faa189455becb1b ]---
RIP: 0010:strlen+0x2a/0x60 lib/string.c:551
Code: 41 57 41 56 41 54 53 49 89 fe 48 c7 c0 ff ff ff ff 49 bf 00 00 00 00 00 fc ff df 48 89 fb 66 90 49 89 c4 48 89 d8 48 c1 e8 03 <42> 0f b6 04 38 84 c0 75 12 48 ff c3 49 8d 44 24 01 43 80 7c 26 01
RSP: 0018:ffff8881c798fc70 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff8881e4149f80
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffffff81b05ef9 R09: ffffed1038f31f9b
R10: ffffed1038f31f9b R11: 1ffff11038f31f9a R12: ffffffffffffffff
R13: 0000000000000000 R14: 0000000000000000 R15: dffffc0000000000
FS:  00007fa8d52a6700(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffe5e21a338 CR3: 00000001ed171000 CR4: 00000000003406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	41 57                	push   %r15
   2:	41 56                	push   %r14
   4:	41 54                	push   %r12
   6:	53                   	push   %rbx
   7:	49 89 fe             	mov    %rdi,%r14
   a:	48 c7 c0 ff ff ff ff 	mov    $0xffffffffffffffff,%rax
  11:	49 bf 00 00 00 00 00 	movabs $0xdffffc0000000000,%r15
  18:	fc ff df
  1b:	48 89 fb             	mov    %rdi,%rbx
  1e:	66 90                	xchg   %ax,%ax
  20:	49 89 c4             	mov    %rax,%r12
  23:	48 89 d8             	mov    %rbx,%rax
  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 12                	jne    0x45
  33:	48 ff c3             	inc    %rbx
  36:	49 8d 44 24 01       	lea    0x1(%r12),%rax
  3b:	43                   	rex.XB
  3c:	80                   	.byte 0x80
  3d:	7c 26                	jl     0x65
  3f:	01                   	.byte 0x1