general protection fault: 0000 [#1] PREEMPT SMP KASAN
Modules linked in:
CPU: 1 PID: 7983 Comm: syz-executor.0 Not tainted 4.14.231-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8880647c4640 task.stack: ffff8880647c8000
RIP: 0010:kobject_uevent_env+0xb2/0xf40 lib/kobject_uevent.c:355
RSP: 0018:ffff8880647cfbe8 EFLAGS: 00010206
RAX: 0000000000000018 RBX: 0000000000000002 RCX: 1ffff1100c8f89e8
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 00000000000000c0
RBP: ffff8880abcaf490 R08: ffffffff8b9af838 R09: 0000000000000003
R10: 0000000000000000 R11: ffff8880647c4640 R12: 00000000000000a0
R13: dffffc0000000000 R14: ffff8880abcaf388 R15: 00000000000000a0
FS:  000000000204a400(0000) GS:ffff8880ba500000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2e526000 CR3: 000000006441a000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 loop_clr_fd+0x59f/0xc20 drivers/block/loop.c:1069
 __lo_release drivers/block/loop.c:1660 [inline]
 lo_release+0xff/0x190 drivers/block/loop.c:1678
 __blkdev_put+0x5aa/0x800 fs/block_dev.c:1803
 romfs_kill_sb fs/romfs/super.c:606 [inline]
 romfs_kill_sb+0x71/0xa0 fs/romfs/super.c:596
 deactivate_locked_super+0x6c/0xd0 fs/super.c:319
 deactivate_super+0x7f/0xa0 fs/super.c:350
 cleanup_mnt+0x186/0x2c0 fs/namespace.c:1183
 task_work_run+0x11f/0x190 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:191 [inline]
 exit_to_usermode_loop+0x1ad/0x200 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+0x4a3/0x640 arch/x86/entry/common.c:297
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x467a57
RSP: 002b:00007ffcf80f7828 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000467a57
RDX: 00007ffcf80f78fa RSI: 0000000000000002 RDI: 00007ffcf80f78f0
RBP: 00007ffcf80f78f0 R08: 00000000ffffffff R09: 00007ffcf80f76c0
R10: 000000000204b8e3 R11: 0000000000000246 R12: 00000000004bee98
R13: 00007ffcf80f89c0 R14: 000000000204b810 R15: 00007ffcf80f8a00
Code: 03 42 80 3c 28 00 0f 85 e4 0b 00 00 4d 8b 64 24 18 4d 85 e4 0f 84 01 0c 00 00 e8 1a 83 58 fa 49 8d 7c 24 20 48 89 f8 48 c1 e8 03 <42> 80 3c 28 00 0f 85 db 0b 00 00 49 8b 6c 24 20 48 85 ed 74 b0 
RIP: kobject_uevent_env+0xb2/0xf40 lib/kobject_uevent.c:355 RSP: ffff8880647cfbe8
---[ end trace 20670ab826aaa34c ]---