loop0: unable to read partition table
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BUG: KCSAN: data-race in __blkdev_get / __blkdev_put

write to 0xffff8881017466a0 of 4 bytes by task 19051 on cpu 1:
 __blkdev_get+0x8c/0x6c0 fs/block_dev.c:1358
 blkdev_get_by_dev+0x9b/0x480 fs/block_dev.c:1453
 blkdev_open+0xb3/0x130 fs/block_dev.c:1548
 do_dentry_open+0x53e/0x830 fs/open.c:826
 vfs_open+0x43/0x50 fs/open.c:940
 do_open fs/namei.c:3361 [inline]
 path_openat+0x184e/0x20b0 fs/namei.c:3494
 do_filp_open+0xd9/0x1f0 fs/namei.c:3521
 do_sys_openat2+0xa3/0x250 fs/open.c:1187
 do_sys_open fs/open.c:1203 [inline]
 __do_sys_openat fs/open.c:1219 [inline]
 __se_sys_openat fs/open.c:1214 [inline]
 __x64_sys_openat+0xef/0x110 fs/open.c:1214
 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff8881017466a0 of 4 bytes by task 1032 on cpu 0:
 __blkdev_put+0x5a/0x460 fs/block_dev.c:1568
 blkdev_put+0x23e/0x2c0 fs/block_dev.c:1638
 blkdev_reread_part block/ioctl.c:105 [inline]
 blkdev_common_ioctl+0x101f/0x1040 block/ioctl.c:510
 blkdev_ioctl+0x16e/0x3c0 block/ioctl.c:579
 block_ioctl+0x6d/0x80 fs/block_dev.c:1664
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:1069 [inline]
 __se_sys_ioctl+0xcb/0x140 fs/ioctl.c:1055
 __x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:1055
 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 1032 Comm: systemd-udevd Not tainted 5.12.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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