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BUG: KASAN: use-after-free in atomic64_read include/asm-generic/atomic-instrumented.h:836 [inline]
BUG: KASAN: use-after-free in atomic_long_read include/asm-generic/atomic-long.h:28 [inline]
BUG: KASAN: use-after-free in __mutex_unlock_slowpath+0x8d/0x5b0 kernel/locking/mutex.c:1237
Read of size 8 at addr ffff88801c5d2658 by task syz-executor.0/29272

CPU: 0 PID: 29272 Comm: syz-executor.0 Not tainted 5.6.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1fb/0x318 lib/dump_stack.c:118
 print_address_description+0x74/0x5c0 mm/kasan/report.c:374
 __kasan_report+0x149/0x1c0 mm/kasan/report.c:506
 kasan_report+0x26/0x50 mm/kasan/common.c:641
 check_memory_region_inline mm/kasan/generic.c:182 [inline]
 check_memory_region+0x2b6/0x2f0 mm/kasan/generic.c:192
 __kasan_check_read+0x11/0x20 mm/kasan/common.c:95
 atomic64_read include/asm-generic/atomic-instrumented.h:836 [inline]
 atomic_long_read include/asm-generic/atomic-long.h:28 [inline]
 __mutex_unlock_slowpath+0x8d/0x5b0 kernel/locking/mutex.c:1237
 mutex_unlock+0xd/0x10 kernel/locking/mutex.c:740
 blkdev_get+0x2b2/0x3e0 fs/block_dev.c:1760
 blkdev_get_by_dev+0x33/0x70 fs/block_dev.c:1839
 lock_rdev drivers/md/md.c:2496 [inline]
 md_import_device+0x3b6/0x710 drivers/md/md.c:3679
 add_new_disk+0x327/0x2730 drivers/md/md.c:6657
 md_ioctl+0x4c14/0x6b20 drivers/md/md.c:7678
 __blkdev_driver_ioctl block/ioctl.c:321 [inline]
 blkdev_ioctl+0x2b8/0x5f0 block/ioctl.c:717
 block_ioctl+0xbd/0x100 fs/block_dev.c:1983
 vfs_ioctl fs/ioctl.c:47 [inline]
 ksys_ioctl fs/ioctl.c:763 [inline]
 __do_sys_ioctl fs/ioctl.c:772 [inline]
 __se_sys_ioctl+0x113/0x190 fs/ioctl.c:770
 __x64_sys_ioctl+0x7b/0x90 fs/ioctl.c:770
 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45c449
Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fbf592a7c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fbf592a86d4 RCX: 000000000045c449
RDX: 0000000020001200 RSI: 0000000040140921 RDI: 0000000000000006
RBP: 000000000076bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000021e R14: 00000000004c4025 R15: 000000000076bf2c

Allocated by task 29272:
 save_stack mm/kasan/common.c:72 [inline]
 set_track mm/kasan/common.c:80 [inline]
 __kasan_kmalloc+0x118/0x1c0 mm/kasan/common.c:515
 kasan_slab_alloc+0xf/0x20 mm/kasan/common.c:523
 slab_post_alloc_hook mm/slab.h:584 [inline]
 slab_alloc mm/slab.c:3320 [inline]
 kmem_cache_alloc+0x1f5/0x2e0 mm/slab.c:3484
 bdev_alloc_inode+0x1b/0x40 fs/block_dev.c:772
 alloc_inode fs/inode.c:231 [inline]
 iget5_locked+0xb2/0x3e0 fs/inode.c:1147
 bdget+0x77/0x480 fs/block_dev.c:905
 blkdev_get_by_dev+0x1d/0x70 fs/block_dev.c:1835
 lock_rdev drivers/md/md.c:2496 [inline]
 md_import_device+0x3b6/0x710 drivers/md/md.c:3679
 add_new_disk+0x327/0x2730 drivers/md/md.c:6657
 md_ioctl+0x4c14/0x6b20 drivers/md/md.c:7678
 __blkdev_driver_ioctl block/ioctl.c:321 [inline]
 blkdev_ioctl+0x2b8/0x5f0 block/ioctl.c:717
 block_ioctl+0xbd/0x100 fs/block_dev.c:1983
 vfs_ioctl fs/ioctl.c:47 [inline]
 ksys_ioctl fs/ioctl.c:763 [inline]
 __do_sys_ioctl fs/ioctl.c:772 [inline]
 __se_sys_ioctl+0x113/0x190 fs/ioctl.c:770
 __x64_sys_ioctl+0x7b/0x90 fs/ioctl.c:770
 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 264:
 save_stack mm/kasan/common.c:72 [inline]
 set_track mm/kasan/common.c:80 [inline]
 kasan_set_free_info mm/kasan/common.c:337 [inline]
 __kasan_slab_free+0x12e/0x1e0 mm/kasan/common.c:476
 kasan_slab_free+0xe/0x10 mm/kasan/common.c:485
 __cache_free mm/slab.c:3426 [inline]
 kmem_cache_free+0x81/0xf0 mm/slab.c:3694
 bdev_free_inode+0x20/0x30 fs/block_dev.c:780
 i_callback+0x4b/0x70 fs/inode.c:220
 rcu_do_batch kernel/rcu/tree.c:2186 [inline]
 rcu_core+0x81b/0x10c0 kernel/rcu/tree.c:2410
 rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2419
 __do_softirq+0x283/0x7bd kernel/softirq.c:292

The buggy address belongs to the object at ffff88801c5d2640
 which belongs to the cache bdev_cache(17:syz0) of size 1368
The buggy address is located 24 bytes inside of
 1368-byte region [ffff88801c5d2640, ffff88801c5d2b98)
The buggy address belongs to the page:
page:ffffea0000717480 refcount:1 mapcount:0 mapping:ffff88808c54ce00 index:0xffff88801c5d2ffe
flags: 0xfffe0000000200(slab)
raw: 00fffe0000000200 ffff88809cb89c48 ffff88809cb89c48 ffff88808c54ce00
raw: ffff88801c5d2ffe ffff88801c5d2040 0000000100000002 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88801c5d2500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88801c5d2580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88801c5d2600: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
                                                    ^
 ffff88801c5d2680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88801c5d2700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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