BUG: KASAN: use-after-free in __lock_acquire+0x3c9f/0x3d50 kernel/locking/lockdep.c:3368
Read of size 8 at addr ffff8801d279b3b0 by task blkid/26096

CPU: 1 PID: 26096 Comm: blkid Not tainted 4.14.0-rc6+ #150
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:16 [inline]
 dump_stack+0x194/0x257 lib/dump_stack.c:52
 print_address_description+0x73/0x250 mm/kasan/report.c:252
 kasan_report_error mm/kasan/report.c:351 [inline]
 kasan_report+0x25b/0x340 mm/kasan/report.c:409
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:430
 __lock_acquire+0x3c9f/0x3d50 kernel/locking/lockdep.c:3368
 lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3994
 __mutex_lock_common kernel/locking/mutex.c:756 [inline]
 __mutex_lock+0x16f/0x19d0 kernel/locking/mutex.c:893
 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
 lo_release+0x6b/0x180 drivers/block/loop.c:1587
 __blkdev_put+0x602/0x7c0 fs/block_dev.c:1782
 blkdev_put+0x85/0x4f0 fs/block_dev.c:1847
 blkdev_close+0x8b/0xb0 fs/block_dev.c:1854
 __fput+0x327/0x7e0 fs/file_table.c:210
 ____fput+0x15/0x20 fs/file_table.c:244
 task_work_run+0x199/0x270 kernel/task_work.c:112
 tracehook_notify_resume include/linux/tracehook.h:191 [inline]
 exit_to_usermode_loop+0x296/0x310 arch/x86/entry/common.c:162
 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline]
 syscall_return_slowpath+0x42f/0x510 arch/x86/entry/common.c:266
 entry_SYSCALL_64_fastpath+0xbc/0xbe
RIP: 0033:0x7f2252c8f2b0
RSP: 002b:00007ffe10113bb8 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f2252c8f2b0
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000023c0030
R13: 0000000000000000 R14: 0000000000000003 R15: 0000000000000005

Allocated by task 26082:
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
 save_stack+0x43/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551
 kmem_cache_alloc_trace+0x136/0x750 mm/slab.c:3627
 kmalloc include/linux/slab.h:493 [inline]
 kzalloc include/linux/slab.h:666 [inline]
 loop_add+0xbf/0xa50 drivers/block/loop.c:1746
 loop_control_ioctl+0x2e9/0x490 drivers/block/loop.c:1953
 vfs_ioctl fs/ioctl.c:45 [inline]
 do_vfs_ioctl+0x1b1/0x1520 fs/ioctl.c:685
 SYSC_ioctl fs/ioctl.c:700 [inline]
 SyS_ioctl+0x8f/0xc0 fs/ioctl.c:691
 entry_SYSCALL_64_fastpath+0x1f/0xbe

Freed by task 26082:
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
 save_stack+0x43/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_slab_free+0x71/0xc0 mm/kasan/kasan.c:524
 __cache_free mm/slab.c:3503 [inline]
 kfree+0xca/0x250 mm/slab.c:3820
 loop_remove+0x9a/0xc0 drivers/block/loop.c:1852
 loop_control_ioctl+0x402/0x490 drivers/block/loop.c:1947
 vfs_ioctl fs/ioctl.c:45 [inline]
 do_vfs_ioctl+0x1b1/0x1520 fs/ioctl.c:685
 SYSC_ioctl fs/ioctl.c:700 [inline]
 SyS_ioctl+0x8f/0xc0 fs/ioctl.c:691
 entry_SYSCALL_64_fastpath+0x1f/0xbe

The buggy address belongs to the object at ffff8801d279b200
 which belongs to the cache kmalloc-1024 of size 1024
The buggy address is located 432 bytes inside of
 1024-byte region [ffff8801d279b200, ffff8801d279b600)
The buggy address belongs to the page:
page:ffffea000749e680 count:1 mapcount:0 mapping:ffff8801d279a000 index:0x0 compound_mapcount: 0
flags: 0x200000000008100(slab|head)
raw: 0200000000008100 ffff8801d279a000 0000000000000000 0000000100000007
raw: ffffea0007202120 ffffea00074c5fa0 ffff8801dac00ac0 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801d279b280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8801d279b300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8801d279b380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                     ^
 ffff8801d279b400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8801d279b480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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