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BUG: KCSAN: data-race in loop_configure / loop_queue_rq

write to 0xffff888101b4ac78 of 4 bytes by task 29629 on cpu 0:
 loop_configure+0xb28/0xc30 drivers/block/loop.c:1105
 lo_ioctl+0x641/0x1290
 blkdev_ioctl+0x215/0x440 block/ioctl.c:616
 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 0xffff888101b4ac78 of 4 bytes by task 21315 on cpu 1:
 loop_queue_rq+0x4b/0x650 drivers/block/loop.c:1820
 __blk_mq_issue_directly+0x66/0x410 block/blk-mq.c:2594
 __blk_mq_try_issue_directly+0x25d/0x2c0 block/blk-mq.c:2647
 blk_mq_request_issue_directly block/blk-mq.c:2681 [inline]
 blk_mq_plug_issue_direct+0x15d/0x5c0 block/blk-mq.c:2701
 blk_mq_flush_plug_list+0x2e0/0x3e0 block/blk-mq.c:2793
 __blk_flush_plug+0x25a/0x2b0 block/blk-core.c:1140
 blk_finish_plug+0x44/0x60 block/blk-core.c:1164
 read_pages+0x4e1/0x560 mm/readahead.c:184
 page_cache_ra_unbounded+0x2de/0x320 mm/readahead.c:270
 do_page_cache_ra mm/readahead.c:300 [inline]
 force_page_cache_ra+0x1c6/0x200 mm/readahead.c:331
 page_cache_sync_ra+0xc8/0xf0 mm/readahead.c:705
 page_cache_sync_readahead include/linux/pagemap.h:1210 [inline]
 filemap_get_pages mm/filemap.c:2600 [inline]
 filemap_read+0x3fd/0x1510 mm/filemap.c:2694
 blkdev_read_iter+0x2c6/0x370 block/fops.c:591
 call_read_iter include/linux/fs.h:2183 [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: 21315 Comm: udevd Tainted: G        W          6.2.0-rc2-syzkaller-00282-g0a71553536d2-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
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