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

write to 0xffff88810197b278 of 4 bytes by task 21731 on cpu 1:
 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 0xffff88810197b278 of 4 bytes by task 1904 on cpu 0:
 loop_queue_rq+0x4b/0x650 drivers/block/loop.c:1811
 __blk_mq_issue_directly+0x66/0x410 block/blk-mq.c:2440
 __blk_mq_try_issue_directly+0x25d/0x2c0 block/blk-mq.c:2493
 blk_mq_try_issue_directly block/blk-mq.c:2517 [inline]
 blk_mq_submit_bio+0xb17/0xe90 block/blk-mq.c:2843
 __submit_bio block/blk-core.c:595 [inline]
 __submit_bio_noacct_mq block/blk-core.c:672 [inline]
 submit_bio_noacct_nocheck+0x83d/0xaa0 block/blk-core.c:689
 submit_bio_noacct+0x696/0x800 block/blk-core.c:796
 submit_bio+0xfb/0x110
 submit_bh_wbc+0x2b0/0x2f0 fs/buffer.c:2719
 submit_bh fs/buffer.c:2725 [inline]
 block_read_full_folio+0x4bd/0x530 fs/buffer.c:2340
 blkdev_read_folio+0x18/0x20 block/fops.c:381
 filemap_read_folio mm/filemap.c:2394 [inline]
 filemap_update_page mm/filemap.c:2477 [inline]
 filemap_get_pages mm/filemap.c:2590 [inline]
 filemap_read+0xabb/0x1430 mm/filemap.c:2660
 blkdev_read_iter+0x2c6/0x370 block/fops.c:598
 call_read_iter include/linux/fs.h:2181 [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:607
 __do_sys_read fs/read_write.c:617 [inline]
 __se_sys_read fs/read_write.c:615 [inline]
 __x64_sys_read+0x3e/0x50 fs/read_write.c:615
 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: 0 PID: 1904 Comm: udevd Not tainted 6.0.0-rc4-syzkaller-00302-gb96fbd602d35-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022
==================================================================
I/O error, dev loop2, sector 0 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 2
I/O error, dev loop4, sector 0 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 2
buffer_io_error: 298 callbacks suppressed
Buffer I/O error on dev loop0, logical block 0, async page read
blk_print_req_error: 397 callbacks suppressed
I/O error, dev loop3, sector 0 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 2
I/O error, dev loop0, sector 0 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 2