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BUG: KCSAN: data-race in __mod_timer / blk_add_timer

write to 0xffff8881026ef388 of 8 bytes by task 26785 on cpu 0:
 __mod_timer+0x731/0xbf0 kernel/time/timer.c:1052
 mod_timer+0x1b/0x20 kernel/time/timer.c:1108
 blk_add_timer+0x191/0x1a0 block/blk-timeout.c:164
 blk_mq_start_request+0x115/0x1b0 block/blk-mq.c:734
 scsi_queue_rq+0x1295/0x15a0 drivers/scsi/scsi_lib.c:1688
 blk_mq_dispatch_rq_list+0x63b/0x1080 block/blk-mq.c:1367
 __blk_mq_sched_dispatch_requests+0x1d5/0x290 block/blk-mq-sched.c:327
 blk_mq_sched_dispatch_requests+0x9f/0x110 block/blk-mq-sched.c:360
 __blk_mq_run_hw_queue+0xbc/0x140 block/blk-mq.c:1487
 __blk_mq_delay_run_hw_queue+0x163/0x2f0 block/blk-mq.c:1564
 blk_mq_run_hw_queue+0x22c/0x250 block/blk-mq.c:1617
 blk_mq_sched_insert_request+0x11d/0x250 block/blk-mq-sched.c:479
 blk_execute_rq_nowait+0xee/0x130 block/blk-exec.c:62
 sg_common_write+0x8df/0x1480 drivers/scsi/sg.c:835
 sg_new_write+0xb32/0xcc0 drivers/scsi/sg.c:773
 sg_ioctl_common drivers/scsi/sg.c:938 [inline]
 sg_ioctl+0xf08/0x18e0 drivers/scsi/sg.c:1164
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:874 [inline]
 __se_sys_ioctl+0xcb/0x140 fs/ioctl.c:860
 __x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:860
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff8881026ef388 of 8 bytes by task 227 on cpu 1:
 blk_add_timer+0x125/0x1a0
 blk_mq_start_request+0x115/0x1b0 block/blk-mq.c:734
 scsi_queue_rq+0x1295/0x15a0 drivers/scsi/scsi_lib.c:1688
 blk_mq_dispatch_rq_list+0x63b/0x1080 block/blk-mq.c:1367
 __blk_mq_sched_dispatch_requests+0x1d5/0x290 block/blk-mq-sched.c:327
 blk_mq_sched_dispatch_requests+0x9f/0x110 block/blk-mq-sched.c:360
 __blk_mq_run_hw_queue+0xbc/0x140 block/blk-mq.c:1487
 __blk_mq_delay_run_hw_queue+0x163/0x2f0 block/blk-mq.c:1564
 blk_mq_run_hw_queue+0x22c/0x250 block/blk-mq.c:1617
 blk_mq_run_hw_queues+0x1d1/0x230 block/blk-mq.c:1680
 blk_mq_requeue_work+0x3ff/0x440 block/blk-mq.c:805
 process_one_work+0x402/0x910 kernel/workqueue.c:2297
 worker_thread+0x636/0xae0 kernel/workqueue.c:2444
 kthread+0x262/0x280 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30

value changed: 0x000000010000abb4 -> 0x000000010000aa92

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 227 Comm: kworker/1:1H Tainted: G        W         5.15.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: kblockd blk_mq_requeue_work
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