blk_update_request: I/O error, dev loop4, sector 0 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 0
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BUG: KCSAN: data-race in blk_mq_unfreeze_queue / blk_queue_enter

read-write to 0xffff888100d775a4 of 4 bytes by task 16669 on cpu 1:
 blk_mq_unfreeze_queue+0x34/0xb0 block/blk-mq.c:194
 loop_set_status+0x69b/0x7c0 drivers/block/loop.c:1405
 lo_ioctl+0x743/0x11d0 drivers/block/loop.c:1484
 blkdev_ioctl+0x1d0/0x3c0 block/ioctl.c:576
 block_ioctl+0x6d/0x80 fs/block_dev.c:1649
 vfs_ioctl fs/ioctl.c:48 [inline]
 __do_sys_ioctl fs/ioctl.c:753 [inline]
 __se_sys_ioctl+0xcb/0x140 fs/ioctl.c:739
 __x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:739
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff888100d775a4 of 4 bytes by task 16648 on cpu 0:
 blk_queue_enter+0x1ca/0x510 block/blk-core.c:466
 bio_queue_enter block/blk-core.c:482 [inline]
 __submit_bio_noacct_mq block/blk-core.c:1018 [inline]
 submit_bio_noacct+0x6f8/0x910 block/blk-core.c:1060
 submit_bio+0x1f3/0x350 block/blk-core.c:1130
 submit_bh_wbc+0x392/0x3d0 fs/buffer.c:3054
 submit_bh fs/buffer.c:3060 [inline]
 block_read_full_page+0x78c/0x870 fs/buffer.c:2339
 blkdev_readpage+0x18/0x20 fs/block_dev.c:622
 generic_file_buffered_read_readpage+0xbf/0x850 mm/filemap.c:2202
 generic_file_buffered_read_pagenotuptodate+0x454/0x8e0 mm/filemap.c:2303
 generic_file_buffered_read_get_pages+0x4f8/0xaf0 mm/filemap.c:2401
 generic_file_buffered_read+0x27f/0x9a0 mm/filemap.c:2481
 generic_file_read_iter+0x80/0x3d0 mm/filemap.c:2633
 blkdev_read_iter+0xb3/0xc0 fs/block_dev.c:1705
 call_read_iter include/linux/fs.h:1895 [inline]
 new_sync_read fs/read_write.c:415 [inline]
 vfs_read+0x552/0x5c0 fs/read_write.c:496
 ksys_read+0xce/0x180 fs/read_write.c:634
 __do_sys_read fs/read_write.c:644 [inline]
 __se_sys_read fs/read_write.c:642 [inline]
 __x64_sys_read+0x3e/0x50 fs/read_write.c:642
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 16648 Comm: systemd-udevd Not tainted 5.10.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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