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: 13282 Comm: syz-executor.4 Not tainted 4.14.171-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8880a551e480 task.stack: ffff8880a4000000
RIP: 0010:kobject_uevent_env+0xa4/0xc80 lib/kobject_uevent.c:355
RSP: 0018:ffff8880a4007b60 EFLAGS: 00010206
RAX: 0000000000000018 RBX: ffff888097c2fb40 RCX: 1ffff11014aa3d9e
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 00000000000000c0
RBP: ffff8880a4007be0 R08: ffff8880a551e480 R09: 0000000000000003
R10: 0000000000000000 R11: ffff8880a551e480 R12: dffffc0000000000
R13: 00000000000000a0 R14: 00000000000000a0 R15: ffff888097c2fc88
FS:  0000000002103940(0000) GS:ffff8880aed00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000001a14c10 CR3: 000000008f0c9000 CR4: 00000000001426e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 kobject_uevent+0x20/0x30 lib/kobject_uevent.c:553
 loop_clr_fd+0x4a7/0xae0 drivers/block/loop.c:1069
 __lo_release drivers/block/loop.c:1660 [inline]
 lo_release+0x112/0x1b0 drivers/block/loop.c:1678
 __blkdev_put+0x434/0x7f0 fs/block_dev.c:1791
 blkdev_put+0x88/0x510 fs/block_dev.c:1856
 blkdev_close+0x8b/0xb0 fs/block_dev.c:1863
 __fput+0x275/0x7a0 fs/file_table.c:210
 ____fput+0x16/0x20 fs/file_table.c:244
 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: 0033:0x415fc1
RSP: 002b:00007fffa4368070 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000007 RCX: 0000000000415fc1
RDX: 0000000000000000 RSI: 00000000000000e4 RDI: 0000000000000006
RBP: 0000000000000001 R08: 00000000ae3040e4 R09: 00000000ae3040e8
R10: 00007fffa4368150 R11: 0000000000000293 R12: 000000000076c920
R13: 000000000076c920 R14: 00000000000fa089 R15: 000000000076c10c
Code: c1 e8 03 42 80 3c 20 00 0f 85 6c 0a 00 00 4d 8b 76 18 4d 85 f6 0f 84 27 02 00 00 e8 17 02 fa fa 49 8d 7e 20 48 89 f8 48 c1 e8 03 <42> 80 3c 20 00 0f 85 3a 0a 00 00 4d 8b 7e 20 4d 85 ff 74 b4 e8 
RIP: kobject_uevent_env+0xa4/0xc80 lib/kobject_uevent.c:355 RSP: ffff8880a4007b60
---[ end trace ef8c8cd4232ccb6e ]---