RBP: 00007fe2dd1d21d0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002
R13: 00007ffc4495a86f R14: 00007fe2dd1d2300 R15: 0000000000022000
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
Modules linked in:
CPU: 1 PID: 30438 Comm: syz-executor.1 Not tainted 4.14.274-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8880a23a0340 task.stack: ffff8880b40c0000
RIP: 0010:sysfs_do_create_link_sd+0x56/0x120 fs/sysfs/symlink.c:35
RSP: 0018:ffff8880b40c7b48 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000010 RCX: 0000000000002fec
RDX: 0000000000000008 RSI: 0000000000000001 RDI: 0000000000000040
RBP: ffffffff87cbc0e0 R08: ffffffff8b9bca20 R09: 00000000000400c7
R10: ffff8880a23a0bf0 R11: ffff8880a23a0340 R12: ffff8880aee11b60
R13: ffffffff87cbc0e0 R14: 0000000000000001 R15: ffff8880ab9d349c
FS:  00007fe2dd1d2700(0000) GS:ffff8880ba500000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f41f1591000 CR3: 00000000a531f000 CR4: 00000000003406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 sysfs_do_create_link fs/sysfs/symlink.c:80 [inline]
 sysfs_create_link+0x5f/0xc0 fs/sysfs/symlink.c:92
 device_add_disk+0x9f8/0xdc0 block/genhd.c:691
 add_disk include/linux/genhd.h:396 [inline]
 loop_add+0x615/0x830 drivers/block/loop.c:1904
 loop_control_ioctl+0x161/0x3f0 drivers/block/loop.c:2027
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x75a/0xff0 fs/ioctl.c:684
 SYSC_ioctl fs/ioctl.c:701 [inline]
 SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x7fe2de85d049
RSP: 002b:00007fe2dd1d2168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fe2de96ff60 RCX: 00007fe2de85d049
RDX: 0000000000000000 RSI: 0000000000004c82 RDI: 0000000000000005
RBP: 00007fe2dd1d21d0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002
R13: 00007ffc4495a86f R14: 00007fe2dd1d2300 R15: 0000000000022000
Code: 84 a1 00 00 00 e8 bb 6a b1 ff 48 c7 c7 40 cd 04 89 e8 6f 63 80 05 48 8d 7b 30 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 a7 00 00 00 4c 8b 6b 30 4d 85 ed 74 4f e8 82 
RIP: sysfs_do_create_link_sd+0x56/0x120 fs/sysfs/symlink.c:35 RSP: ffff8880b40c7b48
---[ end trace 229fc05e7d5923c6 ]---
----------------
Code disassembly (best guess):
   0:	84 a1 00 00 00 e8    	test   %ah,-0x18000000(%rcx)
   6:	bb 6a b1 ff 48       	mov    $0x48ffb16a,%ebx
   b:	c7 c7 40 cd 04 89    	mov    $0x8904cd40,%edi
  11:	e8 6f 63 80 05       	callq  0x5806385
  16:	48 8d 7b 30          	lea    0x30(%rbx),%rdi
  1a:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  21:	fc ff df
  24:	48 89 fa             	mov    %rdi,%rdx
  27:	48 c1 ea 03          	shr    $0x3,%rdx
* 2b:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1) <-- trapping instruction
  2f:	0f 85 a7 00 00 00    	jne    0xdc
  35:	4c 8b 6b 30          	mov    0x30(%rbx),%r13
  39:	4d 85 ed             	test   %r13,%r13
  3c:	74 4f                	je     0x8d
  3e:	e8                   	.byte 0xe8
  3f:	82                   	.byte 0x82