================================================================== BUG: KCSAN: data-race in __blk_mq_sched_dispatch_requests / blk_mq_request_bypass_insert write to 0xffff8881020a6410 of 8 bytes by task 9 on cpu 0: __list_add include/linux/list.h:72 [inline] list_add include/linux/list.h:88 [inline] blk_mq_request_bypass_insert+0x6a/0x140 block/blk-mq.c:2366 blk_mq_sched_insert_request+0xfd/0x220 block/blk-mq-sched.c:441 blk_mq_requeue_work+0x39b/0x400 block/blk-mq.c:1319 process_one_work+0x3d3/0x720 kernel/workqueue.c:2289 worker_thread+0x618/0xa70 kernel/workqueue.c:2436 kthread+0x1a9/0x1e0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 read to 0xffff8881020a6410 of 8 bytes by task 19963 on cpu 1: list_empty_careful include/linux/list.h:329 [inline] __blk_mq_sched_dispatch_requests+0x80/0x270 block/blk-mq-sched.c:284 blk_mq_sched_dispatch_requests+0x8f/0xf0 block/blk-mq-sched.c:339 __blk_mq_run_hw_queue+0x7e/0x100 block/blk-mq.c:1981 __blk_mq_delay_run_hw_queue+0x194/0x390 block/blk-mq.c:2058 blk_mq_run_hw_queue+0x180/0x310 block/blk-mq.c:2109 blk_mq_sched_insert_requests+0x1cb/0x2a0 block/blk-mq-sched.c:493 blk_mq_dispatch_plug_list+0x1e9/0x2c0 block/blk-mq.c:2604 blk_mq_flush_plug_list+0x2ea/0x340 block/blk-mq.c:2646 __blk_flush_plug+0x25a/0x2b0 block/blk-core.c:1244 blk_finish_plug+0x44/0x60 block/blk-core.c:1268 ext4_writepages+0x14a1/0x1970 fs/ext4/inode.c:2855 do_writepages+0x1db/0x350 mm/page-writeback.c:2352 filemap_fdatawrite_wbc+0xd6/0xf0 mm/filemap.c:388 __filemap_fdatawrite_range mm/filemap.c:421 [inline] filemap_write_and_wait_range+0xbf/0x2e0 mm/filemap.c:673 __iomap_dio_rw+0x514/0xf80 fs/iomap/direct-io.c:562 iomap_dio_rw+0x38/0x80 fs/iomap/direct-io.c:681 ext4_dio_read_iter fs/ext4/file.c:79 [inline] ext4_file_read_iter+0x19c/0x200 fs/ext4/file.c:130 call_read_iter include/linux/fs.h:2044 [inline] generic_file_splice_read+0x1de/0x2c0 fs/splice.c:311 do_splice_to fs/splice.c:796 [inline] splice_direct_to_actor+0x2ac/0x660 fs/splice.c:870 do_splice_direct+0xfb/0x180 fs/splice.c:979 do_sendfile+0x3ad/0x900 fs/read_write.c:1246 __do_sys_sendfile64 fs/read_write.c:1311 [inline] __se_sys_sendfile64 fs/read_write.c:1297 [inline] __x64_sys_sendfile64+0x10c/0x150 fs/read_write.c:1297 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae value changed: 0xffff8881020a6408 -> 0xffff8881027b1048 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 19963 Comm: syz-executor.2 Not tainted 5.18.0-rc3-syzkaller-dirty #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================