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: 7065 Comm: syz-executor.0 Not tainted 4.14.126 #20
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff88809497a000 task.stack: ffff88808cd60000
RIP: 0010:kobject_uevent_env+0xa1/0xc23 lib/kobject_uevent.c:350
RSP: 0018:ffff88808cd67b60 EFLAGS: 00010286
RAX: dffffc0000000000 RBX: 0000000000000002 RCX: 1ffff1101292f50e
RDX: 0000000000000014 RSI: 0000000000000002 RDI: ffffffff870751f0
RBP: ffff88808cd67be0 R08: ffff88809497a000 R09: 0000000000000003
R10: 0000000000000000 R11: ffff88809497a000 R12: 00000000000000a0
R13: 0000000000000002 R14: ffff88805bba4380 R15: 00000000000000a0
FS:  0000000001f76940(0000) GS:ffff8880aef00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc614cb2000 CR3: 0000000094b38000 CR4: 00000000001406e0
Call Trace:
 kobject_uevent+0x20/0x26 lib/kobject_uevent.c:553
 loop_clr_fd+0x4a7/0xae0 drivers/block/loop.c:1059
 __lo_release drivers/block/loop.c:1649 [inline]
 lo_release+0x112/0x1b0 drivers/block/loop.c:1667
 __blkdev_put+0x434/0x7f0 fs/block_dev.c:1791
 blkdev_put+0x88/0x510 fs/block_dev.c:1856
 kill_block_super+0xbd/0xf0 fs/super.c:1164
 deactivate_locked_super+0x74/0xe0 fs/super.c:319
 deactivate_super fs/super.c:350 [inline]
 deactivate_super+0x85/0xa0 fs/super.c:346
 cleanup_mnt+0xb2/0x150 fs/namespace.c:1183
 __cleanup_mnt+0x16/0x20 fs/namespace.c:1190
 task_work_run+0x114/0x190 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:191 [inline]
 exit_to_usermode_loop+0x1da/0x220 arch/x86/entry/common.c:164
 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:270 [inline]
 do_syscall_64+0x4bc/0x640 arch/x86/entry/common.c:297
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x45bcf7
RSP: 002b:00007fffa4efa438 EFLAGS: 00000206 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 000000000045bcf7
RDX: 00000000004036a0 RSI: 0000000000000002 RDI: 00007fffa4efa4e0
RBP: 0000000000000aa0 R08: 0000000000000000 R09: 000000000000000b
R10: 0000000000000005 R11: 0000000000000206 R12: 00007fffa4efb570
R13: 0000000001f77940 R14: 0000000000000000 R15: 00007fffa4efb570
Code: fa 83 e2 07 38 d0 7f 09 84 c0 74 05 e8 1f bf 70 fb 41 80 4f 3c 08 e8 45 1e 47 fb 4c 89 fa b8 ff ff 37 00 48 c1 ea 03 48 c1 e0 2a <80> 3c 02 00 74 08 4c 89 ff e8 b7 be 70 fb 49 8b 37 48 c7 c1 e0 
RIP: kobject_uevent_env+0xa1/0xc23 lib/kobject_uevent.c:350 RSP: ffff88808cd67b60
---[ end trace 08862c74f4de2909 ]---