================================================================== BUG: KCSAN: data-race in __blk_mq_sched_dispatch_requests / blk_mq_dispatch_rq_list write to 0xffff888100187ef8 of 4 bytes by task 43 on cpu 1: blk_mq_dispatch_rq_list+0xf4d/0x1090 __blk_mq_do_dispatch_sched block/blk-mq-sched.c:170 [inline] blk_mq_do_dispatch_sched block/blk-mq-sched.c:184 [inline] __blk_mq_sched_dispatch_requests+0x5ec/0xd20 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 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 read to 0xffff888100187ef8 of 4 bytes by task 14757 on cpu 0: __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+0x28b/0xd20 block/blk-mq-sched.c:309 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_get_tag+0x479/0x590 block/blk-mq-tag.c:170 __blk_mq_alloc_requests+0x642/0x9e0 block/blk-mq.c:501 blk_mq_get_new_requests block/blk-mq.c:2884 [inline] blk_mq_submit_bio+0x468/0xd90 block/blk-mq.c:2982 __submit_bio+0x11c/0x350 block/blk-core.c:607 __submit_bio_noacct_mq block/blk-core.c:686 [inline] submit_bio_noacct_nocheck+0x4ad/0x5e0 block/blk-core.c:715 submit_bio_noacct+0x70c/0x8c0 block/blk-core.c:809 submit_bio+0xb7/0xc0 block/blk-core.c:842 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+0x8db/0x1090 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:575 [inline] ext4_file_write_iter+0xa8a/0xe10 fs/ext4/file.c:694 call_write_iter include/linux/fs.h:2020 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x48a/0x790 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:52 [inline] do_syscall_64+0x44/0x110 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x63/0x6b value changed: 0x00000005 -> 0x00000006 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 14757 Comm: syz-executor.4 Not tainted 6.7.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023 ==================================================================