================================================================== BUG: KCSAN: data-race in __blk_mq_sched_dispatch_requests / blk_mq_dispatch_rq_list write to 0xffff8881003ba0f8 of 4 bytes by task 29221 on cpu 0: blk_mq_dispatch_rq_list+0xfd6/0x11f0 __blk_mq_sched_dispatch_requests+0x1d4/0xdd0 block/blk-mq-sched.c:301 blk_mq_sched_dispatch_requests+0x99/0x100 block/blk-mq-sched.c:333 blk_mq_run_hw_queue+0x2a4/0x4c0 block/blk-mq.c:2264 blk_mq_flush_plug_list+0x7f9/0xe00 block/blk-mq.c:2817 blk_add_rq_to_plug+0x108/0x3e0 block/blk-mq.c:1293 blk_mq_submit_bio+0x692/0xd70 block/blk-mq.c:3012 __submit_bio+0x11c/0x350 block/blk-core.c:599 __submit_bio_noacct_mq block/blk-core.c:678 [inline] submit_bio_noacct_nocheck+0x4ad/0x5e0 block/blk-core.c:707 submit_bio_noacct+0x700/0x8a0 block/blk-core.c:801 submit_bio+0xb7/0xc0 block/blk-core.c:834 iomap_dio_submit_bio fs/iomap/direct-io.c:80 [inline] iomap_dio_bio_iter+0xa50/0xbe0 fs/iomap/direct-io.c:417 __iomap_dio_rw+0x8d5/0x1080 fs/iomap/direct-io.c:659 iomap_dio_rw+0x40/0x90 fs/iomap/direct-io.c:748 ext4_dio_write_iter fs/ext4/file.c:609 [inline] ext4_file_write_iter+0xab3/0x1230 fs/ext4/file.c:720 call_write_iter include/linux/fs.h:1985 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x4ab/0x7d0 fs/read_write.c:584 ksys_write+0xeb/0x1a0 fs/read_write.c:637 __do_sys_write fs/read_write.c:649 [inline] __se_sys_write fs/read_write.c:646 [inline] __x64_sys_write+0x42/0x50 fs/read_write.c:646 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd read to 0xffff8881003ba0f8 of 4 bytes by task 42 on cpu 1: __blk_mq_do_dispatch_sched block/blk-mq-sched.c:97 [inline] blk_mq_do_dispatch_sched block/blk-mq-sched.c:184 [inline] __blk_mq_sched_dispatch_requests+0x29b/0xdd0 block/blk-mq-sched.c:309 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+0x434/0x860 kernel/workqueue.c:2600 worker_thread+0x5f2/0xa10 kernel/workqueue.c:2751 kthread+0x1d7/0x210 kernel/kthread.c:388 ret_from_fork+0x48/0x60 arch/x86/kernel/process.c:145 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 value changed: 0x00000007 -> 0x00000008 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 42 Comm: kworker/1:1H Tainted: G W 6.5.0-syzkaller-08894-gb97d64c72259 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023 Workqueue: kblockd blk_mq_run_work_fn ==================================================================