================================================================== BUG: KCSAN: data-race in wbt_issue / wbt_issue write to 0xffff888141d3dd28 of 8 bytes by task 2130 on cpu 1: wbt_issue+0xbd/0xd0 block/blk-wbt.c:611 __rq_qos_issue+0x3b/0x70 block/blk-rq-qos.c:54 rq_qos_issue block/blk-rq-qos.h:159 [inline] blk_mq_start_request+0xd0/0x230 block/blk-mq.c:721 loop_queue_rq+0x3c/0x230 drivers/block/loop.c:2004 blk_mq_dispatch_rq_list+0x570/0xe80 block/blk-mq.c:1369 __blk_mq_do_dispatch_sched block/blk-mq-sched.c:186 [inline] blk_mq_do_dispatch_sched+0x370/0x610 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_run_work_fn+0x3d/0x50 block/blk-mq.c:1820 process_one_work+0x3e1/0x950 kernel/workqueue.c:2275 worker_thread+0x616/0xa70 kernel/workqueue.c:2421 kthread+0x20b/0x230 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 read to 0xffff888141d3dd28 of 8 bytes by task 15001 on cpu 0: wbt_issue+0x76/0xd0 block/blk-wbt.c:609 __rq_qos_issue+0x3b/0x70 block/blk-rq-qos.c:54 rq_qos_issue block/blk-rq-qos.h:159 [inline] blk_mq_start_request+0xd0/0x230 block/blk-mq.c:721 loop_queue_rq+0x3c/0x230 drivers/block/loop.c:2004 blk_mq_dispatch_rq_list+0x570/0xe80 block/blk-mq.c:1369 __blk_mq_do_dispatch_sched block/blk-mq-sched.c:186 [inline] blk_mq_do_dispatch_sched+0x370/0x610 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:491 blk_mq_flush_plug_list+0x2f5/0x400 block/blk-mq.c:1942 blk_flush_plug_list+0x235/0x260 block/blk-core.c:1749 blk_finish_plug+0x44/0x60 block/blk-core.c:1766 read_pages+0x3aa/0x6e0 mm/readahead.c:150 page_cache_ra_unbounded+0x17d/0x4c0 mm/readahead.c:212 do_page_cache_ra mm/readahead.c:267 [inline] force_page_cache_ra+0x226/0x260 mm/readahead.c:298 page_cache_sync_ra+0x178/0x1a0 mm/readahead.c:572 page_cache_sync_readahead include/linux/pagemap.h:840 [inline] filemap_get_pages+0x1ba/0x660 mm/filemap.c:2375 filemap_read+0x1ba/0x7b0 mm/filemap.c:2458 generic_file_read_iter+0x82/0x410 mm/filemap.c:2609 blkdev_read_iter+0xb3/0xc0 fs/block_dev.c:1727 call_read_iter include/linux/fs.h:1971 [inline] new_sync_read fs/read_write.c:415 [inline] vfs_read+0x565/0x5d0 fs/read_write.c:496 ksys_read+0xce/0x180 fs/read_write.c:634 __do_sys_read fs/read_write.c:644 [inline] __se_sys_read fs/read_write.c:642 [inline] __x64_sys_read+0x3e/0x50 fs/read_write.c:642 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: 15001 Comm: systemd-udevd Tainted: G W 5.12.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================