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BUG: KCSAN: data-race in rq_qos_wait / rq_qos_wake_function

write to 0xffff888142022790 of 8 bytes by interrupt on cpu 0:
 __list_del include/linux/list.h:112 [inline]
 __list_del_entry include/linux/list.h:135 [inline]
 list_del_init include/linux/list.h:204 [inline]
 rq_qos_wake_function+0x85/0xe0 block/blk-rq-qos.c:228
 __wake_up_common+0xbc/0x130 kernel/sched/wait.c:108
 __wake_up_common_lock kernel/sched/wait.c:138 [inline]
 __wake_up+0x80/0xc0 kernel/sched/wait.c:157
 wbt_rqw_done+0x17d/0x260 block/blk-wbt.c:165
 __wbt_done block/blk-wbt.c:178 [inline]
 wbt_done+0xcf/0x1c0 block/blk-wbt.c:199
 __rq_qos_done+0x3b/0x70 block/blk-rq-qos.c:45
 rq_qos_done block/blk-rq-qos.h:153 [inline]
 blk_mq_free_request+0x27b/0x330 block/blk-mq.c:529
 __blk_mq_end_request+0x214/0x230 block/blk-mq.c:557
 blk_mq_end_request+0x37/0x50 block/blk-mq.c:566
 end_cmd+0x80/0x140 drivers/block/null_blk/main.c:699
 null_complete_rq+0x18/0x20 drivers/block/null_blk/main.c:726
 blk_complete_reqs block/blk-mq.c:576 [inline]
 blk_done_softirq+0x69/0x90 block/blk-mq.c:581
 __do_softirq+0x13c/0x2c3 kernel/softirq.c:345
 run_ksoftirqd+0x13/0x20 kernel/softirq.c:652
 smpboot_thread_fn+0x34f/0x520 kernel/smpboot.c:165
 kthread+0x20b/0x230 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

read to 0xffff888142022790 of 8 bytes by task 11388 on cpu 1:
 list_is_singular include/linux/list.h:360 [inline]
 wq_has_single_sleeper include/linux/wait.h:142 [inline]
 rq_qos_wait+0x122/0x220 block/blk-rq-qos.c:270
 __wbt_wait block/blk-wbt.c:518 [inline]
 wbt_wait+0x1bb/0x2b0 block/blk-wbt.c:583
 __rq_qos_throttle+0x39/0x70 block/blk-rq-qos.c:72
 rq_qos_throttle block/blk-rq-qos.h:182 [inline]
 blk_mq_submit_bio+0x253/0x1060 block/blk-mq.c:2185
 __submit_bio_noacct_mq block/blk-core.c:1014 [inline]
 submit_bio_noacct+0x7c2/0x9a0 block/blk-core.c:1047
 submit_bio+0x200/0x370 block/blk-core.c:1118
 blk_next_bio block/blk-lib.c:19 [inline]
 __blkdev_issue_zero_pages+0x135/0x2f0 block/blk-lib.c:318
 blkdev_issue_zeroout+0x173/0x2a0 block/blk-lib.c:412
 blk_ioctl_zeroout block/ioctl.c:174 [inline]
 blkdev_common_ioctl+0x1081/0x10a0 block/ioctl.c:469
 blkdev_ioctl+0x16e/0x3c0 block/ioctl.c:577
 block_ioctl+0x6d/0x80 fs/block_dev.c:1658
 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+0x44/0xae

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 11388 Comm: syz-executor.5 Not tainted 5.12.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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