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BUG: KCSAN: data-race in __mod_timer / blk_add_timer

write to 0xffff8881018c0b98 of 8 bytes by task 3099 on cpu 1:
 __mod_timer+0x5fd/0x860 kernel/time/timer.c:1121
 mod_timer+0x1f/0x30 kernel/time/timer.c:1190
 blk_add_timer+0x184/0x190 block/blk-timeout.c:164
 blk_mq_start_request+0x10e/0x2d0 block/blk-mq.c:1260
 loop_queue_rq+0x4c/0x650 drivers/block/loop.c:1851
 __blk_mq_issue_directly block/blk-mq.c:2590 [inline]
 blk_mq_request_issue_directly+0x1d6/0x330 block/blk-mq.c:2675
 blk_mq_plug_issue_direct+0x156/0x520 block/blk-mq.c:2696
 blk_mq_flush_plug_list+0x2b6/0xdc0 block/blk-mq.c:2805
 __blk_flush_plug+0x210/0x260 block/blk-core.c:1150
 blk_finish_plug+0x47/0x60 block/blk-core.c:1174
 do_writepages+0x21a/0x340 mm/page-writeback.c:2560
 filemap_fdatawrite_wbc+0xdb/0xf0 mm/filemap.c:387
 __filemap_fdatawrite_range mm/filemap.c:420 [inline]
 __filemap_fdatawrite mm/filemap.c:426 [inline]
 filemap_flush+0x95/0xc0 mm/filemap.c:453
 sync_blockdev_nowait+0x36/0x50 block/bdev.c:186
 sync_filesystem+0xe0/0x180 fs/sync.c:60
 generic_shutdown_super+0x42/0x210 fs/super.c:669
 kill_block_super+0x2a/0x60 fs/super.c:1667
 ext4_kill_sb+0x44/0x80 fs/ext4/super.c:7330
 deactivate_locked_super+0x7a/0x1c0 fs/super.c:484
 deactivate_super+0x9b/0xb0 fs/super.c:517
 cleanup_mnt+0x272/0x2e0 fs/namespace.c:1256
 __cleanup_mnt+0x19/0x20 fs/namespace.c:1263
 task_work_run+0x135/0x1a0 kernel/task_work.c:180
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0xd6/0xe0 kernel/entry/common.c:171
 exit_to_user_mode_prepare+0x6c/0xb0 kernel/entry/common.c:204
 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline]
 syscall_exit_to_user_mode+0x26/0x140 kernel/entry/common.c:296
 do_syscall_64+0x50/0x110 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

read to 0xffff8881018c0b98 of 8 bytes by task 43 on cpu 0:
 blk_add_timer+0x118/0x190
 blk_mq_start_request+0x10e/0x2d0 block/blk-mq.c:1260
 loop_queue_rq+0x4c/0x650 drivers/block/loop.c:1851
 blk_mq_dispatch_rq_list+0x2d9/0x1090 block/blk-mq.c:2049
 __blk_mq_sched_dispatch_requests+0xc30/0xd20 block/blk-mq-sched.c:315
 blk_mq_sched_dispatch_requests+0x99/0x100 block/blk-mq-sched.c:333
 blk_mq_run_work_fn+0x65/0xe0 block/blk-mq.c:2434
 process_one_work kernel/workqueue.c:2627 [inline]
 process_scheduled_works+0x5b8/0xa30 kernel/workqueue.c:2700
 worker_thread+0x525/0x730 kernel/workqueue.c:2781
 kthread+0x1d7/0x210 kernel/kthread.c:388
 ret_from_fork+0x48/0x60 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242

value changed: 0x00000000fffff057 -> 0x00000000fffff2fb

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 43 Comm: kworker/0:1H Not tainted 6.7.0-rc5-syzkaller-00270-g0e389834672c #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
Workqueue: kblockd blk_mq_run_work_fn
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