RSP: 002b:00007f482fcc2168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f482fe5ef60 RCX: 00007f482fd4c109
RDX: 0000000000000000 RSI: 0000000000004c81 RDI: 0000000000000003
RBP: 00007f482fda608d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffc32454e5f R14: 00007f482fcc2300 R15: 0000000000022000
---[ end trace d302474f4529ceb4 ]---
general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 0 PID: 421 Comm: syz-executor.0 Tainted: G        W         5.10.43-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:strlen+0x1f/0xa0 lib/string.c:568
Code: 48 8b 45 e8 eb 88 0f 1f 44 00 00 48 b8 00 00 00 00 00 fc ff df 55 48 89 fa 48 89 e5 48 c1 ea 03 41 54 49 89 fc 53 48 83 ec 08 <0f> b6 04 02 48 89 fa 83 e2 07 38 d0 7f 04 84 c0 75 4d 41 80 3c 24
RSP: 0018:ffffc90000907c90 EFLAGS: 00010286
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff84262aa9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90000907ca8 R08: 0000000000000001 R09: ffffc90000907cbf
R10: fffff52000120f97 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000008
FS:  00007f482fcc2700(0000) GS:ffff8881f7200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f482fe5f028 CR3: 000000010d6e7000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 kernfs_name_hash+0x16/0xc0 fs/kernfs/dir.c:302
 kernfs_find_ns+0x84/0x210 fs/kernfs/dir.c:841
 kernfs_remove_by_name_ns+0x32/0x80 fs/kernfs/dir.c:1514
 kernfs_remove_by_name include/linux/kernfs.h:608 [inline]
 sysfs_remove_link+0x37/0xa0 fs/sysfs/symlink.c:152
 del_gendisk+0x5f8/0xa60 block/genhd.c:951
 loop_remove drivers/block/loop.c:2194 [inline]
 loop_control_ioctl drivers/block/loop.c:2293 [inline]
 loop_control_ioctl+0x30d/0x3d0 drivers/block/loop.c:2259
 vfs_ioctl fs/ioctl.c:48 [inline]
 __do_sys_ioctl fs/ioctl.c:753 [inline]
 __se_sys_ioctl fs/ioctl.c:739 [inline]
 __x64_sys_ioctl+0x129/0x1a0 fs/ioctl.c:739
 do_syscall_64+0x32/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7f482fd4c109
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:00007f482fcc2168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f482fe5ef60 RCX: 00007f482fd4c109
RDX: 0000000000000000 RSI: 0000000000004c81 RDI: 0000000000000003
RBP: 00007f482fda608d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffc32454e5f R14: 00007f482fcc2300 R15: 0000000000022000
Modules linked in:
---[ end trace d302474f4529ceb5 ]---
RIP: 0010:strlen+0x1f/0xa0 lib/string.c:568
Code: 48 8b 45 e8 eb 88 0f 1f 44 00 00 48 b8 00 00 00 00 00 fc ff df 55 48 89 fa 48 89 e5 48 c1 ea 03 41 54 49 89 fc 53 48 83 ec 08 <0f> b6 04 02 48 89 fa 83 e2 07 38 d0 7f 04 84 c0 75 4d 41 80 3c 24
RSP: 0018:ffffc90000907c90 EFLAGS: 00010286
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff84262aa9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90000907ca8 R08: 0000000000000001 R09: ffffc90000907cbf
R10: fffff52000120f97 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000008
FS:  00007f482fcc2700(0000) GS:ffff8881f7200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f482fe5f028 CR3: 000000010d6e7000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	48 8b 45 e8          	mov    -0x18(%rbp),%rax
   4:	eb 88                	jmp    0xffffff8e
   6:	0f 1f 44 00 00       	nopl   0x0(%rax,%rax,1)
   b:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  12:	fc ff df
  15:	55                   	push   %rbp
  16:	48 89 fa             	mov    %rdi,%rdx
  19:	48 89 e5             	mov    %rsp,%rbp
  1c:	48 c1 ea 03          	shr    $0x3,%rdx
  20:	41 54                	push   %r12
  22:	49 89 fc             	mov    %rdi,%r12
  25:	53                   	push   %rbx
  26:	48 83 ec 08          	sub    $0x8,%rsp
* 2a:	0f b6 04 02          	movzbl (%rdx,%rax,1),%eax <-- trapping instruction
  2e:	48 89 fa             	mov    %rdi,%rdx
  31:	83 e2 07             	and    $0x7,%edx
  34:	38 d0                	cmp    %dl,%al
  36:	7f 04                	jg     0x3c
  38:	84 c0                	test   %al,%al
  3a:	75 4d                	jne    0x89
  3c:	41                   	rex.B
  3d:	80                   	.byte 0x80
  3e:	3c 24                	cmp    $0x24,%al