================================================================== BUG: KCSAN: data-race in dd_has_work / dd_insert_requests write to 0xffff8881038d8a28 of 8 bytes by task 10789 on cpu 1: __list_add include/linux/list.h:70 [inline] list_add_tail include/linux/list.h:100 [inline] dd_insert_request block/mq-deadline.c:519 [inline] dd_insert_requests+0x390/0x4f0 block/mq-deadline.c:535 blk_mq_sched_insert_requests+0xc3/0x210 block/blk-mq-sched.c:486 blk_mq_flush_plug_list+0x2f5/0x400 block/blk-mq.c:1942 blk_flush_plug_list+0x235/0x260 block/blk-core.c:1748 blk_finish_plug+0x44/0x60 block/blk-core.c:1765 ext4_writepages+0x18dd/0x1e70 fs/ext4/inode.c:2852 do_writepages+0x7b/0x150 mm/page-writeback.c:2352 __filemap_fdatawrite_range+0x19d/0x1d0 mm/filemap.c:424 file_write_and_wait_range+0x9f/0x120 mm/filemap.c:763 ext4_sync_file+0x105/0x6e0 fs/ext4/fsync.c:151 vfs_fsync_range+0x107/0x120 fs/sync.c:200 generic_write_sync include/linux/fs.h:2760 [inline] ext4_buffered_write_iter+0x38f/0x3e0 fs/ext4/file.c:277 ext4_file_write_iter+0x48a/0x10b0 fs/ext4/file.c:502 call_write_iter include/linux/fs.h:1901 [inline] do_iter_readv_writev+0x2cb/0x360 fs/read_write.c:740 do_iter_write+0x112/0x4c0 fs/read_write.c:866 vfs_iter_write+0x4c/0x70 fs/read_write.c:907 iter_file_splice_write+0x40a/0x750 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+0xf5/0x170 fs/splice.c:979 do_sendfile+0x7a6/0xe20 fs/read_write.c:1260 __do_sys_sendfile64 fs/read_write.c:1319 [inline] __se_sys_sendfile64 fs/read_write.c:1311 [inline] __x64_sys_sendfile64+0xa9/0x130 fs/read_write.c:1311 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae read to 0xffff8881038d8a28 of 8 bytes by task 10790 on cpu 0: list_empty_careful include/linux/list.h:319 [inline] dd_has_work+0xd3/0xe0 block/mq-deadline.c:584 __blk_mq_do_dispatch_sched block/blk-mq-sched.c:135 [inline] blk_mq_do_dispatch_sched+0x138/0x610 block/blk-mq-sched.c:199 __blk_mq_sched_dispatch_requests+0x1fd/0x2a0 block/blk-mq-sched.c:310 blk_mq_sched_dispatch_requests+0x9f/0x110 block/blk-mq-sched.c:341 __blk_mq_run_hw_queue+0xc1/0x140 block/blk-mq.c:1488 __blk_mq_delay_run_hw_queue+0x188/0x330 block/blk-mq.c:1565 blk_mq_run_hw_queue+0x231/0x260 block/blk-mq.c:1618 blk_mq_sched_insert_requests+0x144/0x210 block/blk-mq-sched.c:501 blk_mq_flush_plug_list+0x2f5/0x400 block/blk-mq.c:1942 blk_flush_plug_list+0x235/0x260 block/blk-core.c:1748 blk_finish_plug+0x44/0x60 block/blk-core.c:1765 ext4_writepages+0x18dd/0x1e70 fs/ext4/inode.c:2852 do_writepages+0x7b/0x150 mm/page-writeback.c:2352 __filemap_fdatawrite_range+0x19d/0x1d0 mm/filemap.c:424 file_write_and_wait_range+0x9f/0x120 mm/filemap.c:763 ext4_sync_file+0x105/0x6e0 fs/ext4/fsync.c:151 vfs_fsync_range+0x107/0x120 fs/sync.c:200 generic_write_sync include/linux/fs.h:2760 [inline] ext4_buffered_write_iter+0x38f/0x3e0 fs/ext4/file.c:277 ext4_file_write_iter+0x48a/0x10b0 fs/ext4/file.c:502 call_write_iter include/linux/fs.h:1901 [inline] do_iter_readv_writev+0x2cb/0x360 fs/read_write.c:740 do_iter_write+0x112/0x4c0 fs/read_write.c:866 vfs_iter_write+0x4c/0x70 fs/read_write.c:907 iter_file_splice_write+0x40a/0x750 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+0xf5/0x170 fs/splice.c:979 do_sendfile+0x7a6/0xe20 fs/read_write.c:1260 __do_sys_sendfile64 fs/read_write.c:1319 [inline] __se_sys_sendfile64 fs/read_write.c:1311 [inline] __x64_sys_sendfile64+0xa9/0x130 fs/read_write.c:1311 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 10790 Comm: syz-executor.4 Not tainted 5.11.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================