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BUG: KASAN: use-after-free in trace_event_get_offsets_lock include/trace/events/lock.h:39 [inline]
BUG: KASAN: use-after-free in perf_trace_lock+0x3a6/0x4b0 include/trace/events/lock.h:39
Read of size 8 at addr ffff88800fc89690 by task syz-executor.5/22672

CPU: 0 PID: 22672 Comm: syz-executor.5 Not tainted 4.14.181-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x1b2/0x283 lib/dump_stack.c:58
 print_address_description.cold+0x54/0x1dc mm/kasan/report.c:252
 kasan_report_error mm/kasan/report.c:351 [inline]
 kasan_report mm/kasan/report.c:409 [inline]
 kasan_report.cold+0xa9/0x2b9 mm/kasan/report.c:393
 trace_event_get_offsets_lock include/trace/events/lock.h:39 [inline]
 perf_trace_lock+0x3a6/0x4b0 include/trace/events/lock.h:39
 trace_lock_release include/trace/events/lock.h:58 [inline]
 lock_release+0x4df/0x7f0 kernel/locking/lockdep.c:4016
 __mutex_unlock_slowpath+0x75/0x780 kernel/locking/mutex.c:1018
 blkdev_get+0x537/0x8a0 fs/block_dev.c:1655
 blkdev_get_by_dev+0x3b/0x70 fs/block_dev.c:1734
 lock_rdev+0x79/0x110 drivers/md/md.c:2293
 md_import_device+0x1b1/0x430 drivers/md/md.c:3466
 add_new_disk+0x4a8/0x1510 drivers/md/md.c:6320
 md_ioctl+0x36b4/0x4920 drivers/md/md.c:7338
 __blkdev_driver_ioctl block/ioctl.c:297 [inline]
 blkdev_ioctl+0x91d/0x17c0 block/ioctl.c:594
 block_ioctl+0xd9/0x120 fs/block_dev.c:1881
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x75a/0xfe0 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: 0033:0x45ca29
RSP: 002b:00007f5d7f21bc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000004e1640 RCX: 000000000045ca29
RDX: 0000000020001200 RSI: 0000000040140921 RDI: 0000000000000005
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000220 R14: 00000000004c465d R15: 00007f5d7f21c6d4

Allocated by task 22672:
 save_stack mm/kasan/kasan.c:447 [inline]
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc.part.0+0x4f/0xd0 mm/kasan/kasan.c:551
 kmem_cache_alloc+0x124/0x3c0 mm/slab.c:3552
 bdev_alloc_inode+0x18/0x40 fs/block_dev.c:754
 alloc_inode+0x5d/0x170 fs/inode.c:210
 iget5_locked+0x16c/0x450 fs/inode.c:1050
 bdget+0x83/0x4c0 fs/block_dev.c:895
 blkdev_get_by_dev+0x21/0x70 fs/block_dev.c:1730
 lock_rdev+0x79/0x110 drivers/md/md.c:2293
 md_import_device+0x1b1/0x430 drivers/md/md.c:3466
 add_new_disk+0x4a8/0x1510 drivers/md/md.c:6320
 md_ioctl+0x36b4/0x4920 drivers/md/md.c:7338
 __blkdev_driver_ioctl block/ioctl.c:297 [inline]
 blkdev_ioctl+0x91d/0x17c0 block/ioctl.c:594
 block_ioctl+0xd9/0x120 fs/block_dev.c:1881
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x75a/0xfe0 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

Freed by task 6352:
 save_stack mm/kasan/kasan.c:447 [inline]
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_slab_free+0xaf/0x190 mm/kasan/kasan.c:524
 __cache_free mm/slab.c:3496 [inline]
 kmem_cache_free+0x7c/0x2b0 mm/slab.c:3758
 __rcu_reclaim kernel/rcu/rcu.h:195 [inline]
 rcu_do_batch kernel/rcu/tree.c:2699 [inline]
 invoke_rcu_callbacks kernel/rcu/tree.c:2962 [inline]
 __rcu_process_callbacks kernel/rcu/tree.c:2929 [inline]
 rcu_process_callbacks+0x78d/0x1180 kernel/rcu/tree.c:2946
 __do_softirq+0x254/0x9bf kernel/softirq.c:288

The buggy address belongs to the object at ffff88800fc89600
 which belongs to the cache bdev_cache of size 1360
The buggy address is located 144 bytes inside of
 1360-byte region [ffff88800fc89600, ffff88800fc89b50)
The buggy address belongs to the page:
page:ffffea00003f2240 count:1 mapcount:0 mapping:ffff88800fc89000 index:0xffff88800fc89ffe
flags: 0xfffe0000000100(slab)
raw: 00fffe0000000100 ffff88800fc89000 ffff88800fc89ffe 0000000100000002
raw: ffffea0000607aa0 ffff8880aa9db348 ffff8880aa9da840 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88800fc89580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88800fc89600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88800fc89680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                         ^
 ffff88800fc89700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88800fc89780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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