==================================================================
BUG: KCSAN: data-race in loop_configure / loop_queue_rq

write to 0xffff888101ac1878 of 4 bytes by task 20137 on cpu 0:
 loop_configure+0xb28/0xc30 drivers/block/loop.c:1105
 lo_ioctl+0x641/0x1290
 blkdev_ioctl+0x20e/0x440 block/ioctl.c:614
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl+0xcb/0x140 fs/ioctl.c:856
 __x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

read to 0xffff888101ac1878 of 4 bytes by task 4339 on cpu 1:
 loop_queue_rq+0x4b/0x650 drivers/block/loop.c:1811
 __blk_mq_issue_directly+0x66/0x410 block/blk-mq.c:2529
 __blk_mq_try_issue_directly+0x25d/0x2c0 block/blk-mq.c:2582
 blk_mq_try_issue_directly block/blk-mq.c:2606 [inline]
 blk_mq_submit_bio+0xb17/0xe90 block/blk-mq.c:2932
 __submit_bio block/blk-core.c:591 [inline]
 __submit_bio_noacct_mq block/blk-core.c:668 [inline]
 submit_bio_noacct_nocheck+0x83d/0xaa0 block/blk-core.c:685
 submit_bio_noacct+0x6a5/0x810 block/blk-core.c:791
 submit_bio+0xfb/0x110 block/blk-core.c:827
 submit_bh_wbc+0x2b0/0x2f0 fs/buffer.c:2702
 submit_bh fs/buffer.c:2707 [inline]
 block_read_full_folio+0x4bd/0x530 fs/buffer.c:2325
 blkdev_read_folio+0x18/0x20 block/fops.c:381
 filemap_read_folio mm/filemap.c:2407 [inline]
 filemap_update_page mm/filemap.c:2492 [inline]
 filemap_get_pages mm/filemap.c:2605 [inline]
 filemap_read+0xdd1/0x1510 mm/filemap.c:2675
 blkdev_read_iter+0x2c6/0x370 block/fops.c:598
 call_read_iter include/linux/fs.h:2185 [inline]
 new_sync_read fs/read_write.c:389 [inline]
 vfs_read+0x3a5/0x560 fs/read_write.c:470
 ksys_read+0xe8/0x1a0 fs/read_write.c:613
 __do_sys_read fs/read_write.c:623 [inline]
 __se_sys_read fs/read_write.c:621 [inline]
 __x64_sys_read+0x3e/0x50 fs/read_write.c:621
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x00000000 -> 0x00000001

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 4339 Comm: udevd Not tainted 6.1.0-rc3-syzkaller-00288-gb208b9fbbcba-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
==================================================================
I/O error, dev loop0, sector 0 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 2
Buffer I/O error on dev loop5, logical block 0, async page read
Buffer I/O error on dev loop5, logical block 2, async page read
Buffer I/O error on dev loop5, logical block 3, async page read
Buffer I/O error on dev loop2, logical block 0, async page read
Buffer I/O error on dev loop2, logical block 2, async page read
I/O error, dev loop3, sector 0 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 2
Buffer I/O error on dev loop0, logical block 0, async page read
Buffer I/O error on dev loop0, logical block 0, async page read