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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+0x93/0x6a0 kernel/locking/mutex.c:1237
Read of size 8 at addr ffff88804d311658 by task syz-executor.4/23265

CPU: 1 PID: 23265 Comm: syz-executor.4 Not tainted 5.5.0-rc2-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+0x197/0x210 lib/dump_stack.c:118
 print_address_description.constprop.0.cold+0xd4/0x30b mm/kasan/report.c:374
 __kasan_report.cold+0x1b/0x41 mm/kasan/report.c:506
 kasan_report+0x12/0x20 mm/kasan/common.c:639
 check_memory_region_inline mm/kasan/generic.c:185 [inline]
 check_memory_region+0x134/0x1a0 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+0x93/0x6a0 kernel/locking/mutex.c:1237
 mutex_unlock+0xd/0x10 kernel/locking/mutex.c:740
 blkdev_get+0x1e9/0x2c0 fs/block_dev.c:1760
 blkdev_get_by_dev+0x42/0x80 fs/block_dev.c:1839
 lock_rdev+0xa0/0x160 drivers/md/md.c:2405
 md_import_device+0x221/0x520 drivers/md/md.c:3588
 add_new_disk+0x53f/0x1a20 drivers/md/md.c:6513
 md_ioctl+0x4a19/0x5ea0 drivers/md/md.c:7534
 __blkdev_driver_ioctl block/ioctl.c:277 [inline]
 blkdev_ioctl+0x1302/0x1df0 block/ioctl.c:582
 block_ioctl+0xee/0x130 fs/block_dev.c:1983
 vfs_ioctl fs/ioctl.c:47 [inline]
 file_ioctl fs/ioctl.c:545 [inline]
 do_vfs_ioctl+0x977/0x14e0 fs/ioctl.c:732
 ksys_ioctl+0xab/0xd0 fs/ioctl.c:749
 __do_sys_ioctl fs/ioctl.c:756 [inline]
 __se_sys_ioctl fs/ioctl.c:754 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:754
 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45a919
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:00007fe036218c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045a919
RDX: 0000000020001200 RSI: 0000000040140921 RDI: 0000000000000003
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe0362196d4
R13: 00000000004c2230 R14: 00000000004d7398 R15: 00000000ffffffff

Allocated by task 23265:
 save_stack+0x23/0x90 mm/kasan/common.c:72
 set_track mm/kasan/common.c:80 [inline]
 __kasan_kmalloc mm/kasan/common.c:513 [inline]
 __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:486
 kasan_slab_alloc+0xf/0x20 mm/kasan/common.c:521
 slab_post_alloc_hook mm/slab.h:584 [inline]
 slab_alloc mm/slab.c:3320 [inline]
 kmem_cache_alloc+0x121/0x710 mm/slab.c:3484
 bdev_alloc_inode+0x1c/0x50 fs/block_dev.c:772
 alloc_inode+0x68/0x1e0 fs/inode.c:230
 iget5_locked fs/inode.c:1139 [inline]
 iget5_locked+0x63/0xe0 fs/inode.c:1132
 bdget+0x97/0x550 fs/block_dev.c:905
 blkdev_get_by_dev+0x27/0x80 fs/block_dev.c:1835
 lock_rdev+0xa0/0x160 drivers/md/md.c:2405
 md_import_device+0x221/0x520 drivers/md/md.c:3588
 add_new_disk+0x53f/0x1a20 drivers/md/md.c:6513
 md_ioctl+0x4a19/0x5ea0 drivers/md/md.c:7534
 __blkdev_driver_ioctl block/ioctl.c:277 [inline]
 blkdev_ioctl+0x1302/0x1df0 block/ioctl.c:582
 block_ioctl+0xee/0x130 fs/block_dev.c:1983
 vfs_ioctl fs/ioctl.c:47 [inline]
 file_ioctl fs/ioctl.c:545 [inline]
 do_vfs_ioctl+0x977/0x14e0 fs/ioctl.c:732
 ksys_ioctl+0xab/0xd0 fs/ioctl.c:749
 __do_sys_ioctl fs/ioctl.c:756 [inline]
 __se_sys_ioctl fs/ioctl.c:754 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:754
 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 16:
 save_stack+0x23/0x90 mm/kasan/common.c:72
 set_track mm/kasan/common.c:80 [inline]
 kasan_set_free_info mm/kasan/common.c:335 [inline]
 __kasan_slab_free+0x102/0x150 mm/kasan/common.c:474
 kasan_slab_free+0xe/0x10 mm/kasan/common.c:483
 __cache_free mm/slab.c:3426 [inline]
 kmem_cache_free+0x86/0x320 mm/slab.c:3694
 bdev_free_inode+0x20/0x30 fs/block_dev.c:780
 i_callback+0x44/0x80 fs/inode.c:219
 __rcu_reclaim kernel/rcu/rcu.h:222 [inline]
 rcu_do_batch kernel/rcu/tree.c:2183 [inline]
 rcu_core+0x570/0x1540 kernel/rcu/tree.c:2408
 rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2417
 __do_softirq+0x262/0x98c kernel/softirq.c:292

The buggy address belongs to the object at ffff88804d311640
 which belongs to the cache bdev_cache(71:syz4) of size 1368
The buggy address is located 24 bytes inside of
 1368-byte region [ffff88804d311640, ffff88804d311b98)
The buggy address belongs to the page:
page:ffffea000134c440 refcount:1 mapcount:0 mapping:ffff88806a17c380 index:0xffff88804d311ffe
raw: 00fffe0000000200 ffff8880a710fc48 ffff8880a710fc48 ffff88806a17c380
raw: ffff88804d311ffe ffff88804d311040 0000000100000002 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88804d311500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88804d311580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88804d311600: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
                                                    ^
 ffff88804d311680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88804d311700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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