syzbot

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BUG: KCSAN: data-race in blkdev_get_whole / blkdev_put

write to 0xffff8881018be720 of 4 bytes by task 24073 on cpu 0:
 blkdev_get_whole+0x308/0x350 fs/block_dev.c:1270
 blkdev_get_by_dev+0x2ad/0x8d0 fs/block_dev.c:1417
 blkdev_open+0xb3/0x130 fs/block_dev.c:1512
 do_dentry_open+0x52c/0x860 fs/open.c:822
 vfs_open+0x43/0x50 fs/open.c:945
 do_open fs/namei.c:3372 [inline]
 path_openat+0x17b2/0x1e90 fs/namei.c:3505
 do_filp_open+0xe9/0x200 fs/namei.c:3532
 do_sys_openat2+0xa3/0x290 fs/open.c:1200
 do_sys_open fs/open.c:1216 [inline]
 __do_sys_open fs/open.c:1224 [inline]
 __se_sys_open fs/open.c:1220 [inline]
 __x64_sys_open+0xe2/0x110 fs/open.c:1220
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff8881018be720 of 4 bytes by task 24110 on cpu 1:
 blkdev_put+0x3b/0x4e0 fs/block_dev.c:1531
 blkdev_close+0x47/0x50 fs/block_dev.c:1586
 __fput+0x295/0x520 fs/file_table.c:280
 ____fput+0x11/0x20 fs/file_table.c:313
 task_work_run+0xae/0x130 kernel/task_work.c:164
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:175 [inline]
 exit_to_user_mode_prepare+0x156/0x190 kernel/entry/common.c:209
 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
 syscall_exit_to_user_mode+0x20/0x40 kernel/entry/common.c:302
 do_syscall_64+0x49/0x90 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x00000001 -> 0x00000002

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 24110 Comm: syz-executor.5 Not tainted 5.14.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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