================================================================== BUG: KCSAN: data-race in blk_mq_dispatch_rq_list / blk_mq_dispatch_rq_list write to 0xffff8881027ce568 of 8 bytes by task 199 on cpu 1: blk_mq_dispatch_rq_list+0xadb/0x1080 block/blk-mq.c:1386 __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:1480 __blk_mq_delay_run_hw_queue+0x163/0x2f0 block/blk-mq.c:1557 blk_mq_run_hw_queue+0x22c/0x250 block/blk-mq.c:1610 blk_mq_run_hw_queues+0x1d1/0x230 block/blk-mq.c:1673 blk_mq_requeue_work+0x3ff/0x440 block/blk-mq.c:798 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 read to 0xffff8881027ce568 of 8 bytes by task 32236 on cpu 0: blk_mq_dispatch_rq_list+0xac8/0x1080 block/blk-mq.c:1386 __blk_mq_do_dispatch_sched block/blk-mq-sched.c:201 [inline] blk_mq_do_dispatch_sched+0x3b5/0x640 block/blk-mq-sched.c:214 __blk_mq_sched_dispatch_requests+0x1eb/0x290 blk_mq_sched_dispatch_requests+0x9f/0x110 block/blk-mq-sched.c:360 __blk_mq_run_hw_queue+0xbc/0x140 block/blk-mq.c:1480 __blk_mq_delay_run_hw_queue+0x163/0x2f0 block/blk-mq.c:1557 blk_mq_run_hw_queue+0x22c/0x250 block/blk-mq.c:1610 blk_mq_sched_insert_requests+0x12b/0x1f0 block/blk-mq-sched.c:513 blk_mq_flush_plug_list+0x302/0x3d0 block/blk-mq.c:1935 blk_flush_plug_list+0x235/0x260 block/blk-core.c:1718 blk_finish_plug+0x44/0x60 block/blk-core.c:1735 __iomap_dio_rw+0xca7/0x1010 fs/iomap/direct-io.c:570 iomap_dio_rw+0x30/0x70 fs/iomap/direct-io.c:649 ext4_dio_write_iter fs/ext4/file.c:568 [inline] ext4_file_write_iter+0xa59/0x11f0 fs/ext4/file.c:678 call_write_iter include/linux/fs.h:2163 [inline] do_iter_readv_writev+0x2de/0x380 fs/read_write.c:729 do_iter_write+0x192/0x5c0 fs/read_write.c:855 vfs_iter_write+0x4c/0x70 fs/read_write.c:896 iter_file_splice_write+0x43a/0x790 fs/splice.c:689 do_splice_from fs/splice.c:767 [inline] direct_splice_actor+0x80/0xa0 fs/splice.c:936 splice_direct_to_actor+0x345/0x650 fs/splice.c:891 do_splice_direct+0x106/0x190 fs/splice.c:979 do_sendfile+0x63e/0xbb0 fs/read_write.c:1249 __do_sys_sendfile64 fs/read_write.c:1314 [inline] __se_sys_sendfile64 fs/read_write.c:1300 [inline] __x64_sys_sendfile64+0x102/0x140 fs/read_write.c:1300 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 value changed: 0x0000000000009001 -> 0x0000000000009002 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 32236 Comm: syz-executor.4 Not tainted 5.15.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ================================================================== syz-executor.4 (32236) used greatest stack depth: 10192 bytes left