================================================================== BUG: KCSAN: data-race in __blk_mq_sched_dispatch_requests / blk_mq_request_bypass_insert write to 0xffff8881028db810 of 8 bytes by task 227 on cpu 1: __list_add include/linux/list.h:72 [inline] list_add include/linux/list.h:88 [inline] blk_mq_request_bypass_insert+0x6a/0x130 block/blk-mq.c:2345 blk_mq_sched_insert_request+0xfd/0x220 block/blk-mq-sched.c:434 blk_mq_requeue_work+0x38b/0x3f0 block/blk-mq.c:1306 process_one_work+0x3f6/0x960 kernel/workqueue.c:2307 worker_thread+0x616/0xa70 kernel/workqueue.c:2454 kthread+0x1bf/0x1e0 kernel/kthread.c:377 ret_from_fork+0x1f/0x30 read to 0xffff8881028db810 of 8 bytes by task 20906 on cpu 0: list_empty_careful include/linux/list.h:329 [inline] __blk_mq_sched_dispatch_requests+0x80/0x270 block/blk-mq-sched.c:277 blk_mq_sched_dispatch_requests+0x9f/0x110 block/blk-mq-sched.c:332 __blk_mq_run_hw_queue+0x7e/0x100 block/blk-mq.c:1968 __blk_mq_delay_run_hw_queue+0x19c/0x390 block/blk-mq.c:2045 blk_mq_run_hw_queue+0x180/0x310 block/blk-mq.c:2096 blk_mq_sched_insert_requests+0x1cc/0x2a0 block/blk-mq-sched.c:486 blk_mq_flush_plug_list+0x5c3/0x6c0 block/blk-mq.c:2628 blk_flush_plug+0x25a/0x2b0 block/blk-core.c:1282 blk_finish_plug+0x44/0x60 block/blk-core.c:1306 ext4_writepages+0x1981/0x1e80 fs/ext4/inode.c:2829 do_writepages+0x1cb/0x330 mm/page-writeback.c:2364 filemap_fdatawrite_wbc mm/filemap.c:384 [inline] __filemap_fdatawrite_range mm/filemap.c:417 [inline] file_write_and_wait_range+0x134/0x1d0 mm/filemap.c:775 ext4_sync_file+0x105/0x6e0 fs/ext4/fsync.c:151 vfs_fsync_range+0x107/0x120 fs/sync.c:182 generic_write_sync include/linux/fs.h:2884 [inline] ext4_buffered_write_iter+0x318/0x360 fs/ext4/file.c:275 ext4_file_write_iter+0x2e7/0x11f0 call_write_iter include/linux/fs.h:2074 [inline] do_iter_readv_writev+0x2de/0x380 fs/read_write.c:725 do_iter_write+0x192/0x5c0 fs/read_write.c:851 vfs_iter_write+0x4c/0x70 fs/read_write.c:892 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+0x675/0xc40 fs/read_write.c:1245 __do_sys_sendfile64 fs/read_write.c:1310 [inline] __se_sys_sendfile64 fs/read_write.c:1296 [inline] __x64_sys_sendfile64+0x102/0x140 fs/read_write.c:1296 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae value changed: 0xffff8881028db808 -> 0xffff88810286a048 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 20906 Comm: syz-executor.3 Not tainted 5.17.0-rc2-syzkaller-00060-g88808fbbead4 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================