================================================================== BUG: KCSAN: data-race in wb_timer_fn / wbt_inflight_cb write to 0xffff88810398d504 of 4 bytes by interrupt on cpu 1: calc_wb_limits block/blk-wbt.c:304 [inline] scale_up block/blk-wbt.c:313 [inline] wb_timer_fn+0x403/0xa00 block/blk-wbt.c:382 blk_stat_timer_fn+0x3f4/0x410 block/blk-stat.c:99 call_timer_fn+0x2e/0x240 kernel/time/timer.c:1410 expire_timers+0x116/0x260 kernel/time/timer.c:1455 __run_timers+0x338/0x3d0 kernel/time/timer.c:1747 run_timer_softirq+0x19/0x30 kernel/time/timer.c:1760 __do_softirq+0x12c/0x2b1 kernel/softirq.c:298 run_ksoftirqd+0x13/0x20 kernel/softirq.c:653 smpboot_thread_fn+0x34f/0x520 kernel/smpboot.c:165 kthread+0x1fd/0x220 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 read to 0xffff88810398d504 of 4 bytes by task 20888 on cpu 0: rwb_enabled block/blk-wbt.c:80 [inline] get_limit block/blk-wbt.c:458 [inline] wbt_inflight_cb+0x3f/0x220 block/blk-wbt.c:495 rq_qos_wait+0xac/0x210 block/blk-rq-qos.c:266 __wbt_wait block/blk-wbt.c:518 [inline] wbt_wait+0x1bb/0x2b0 block/blk-wbt.c:583 __rq_qos_throttle+0x39/0x70 block/blk-rq-qos.c:72 rq_qos_throttle block/blk-rq-qos.h:182 [inline] blk_mq_submit_bio+0x233/0x1020 block/blk-mq.c:2174 __submit_bio_noacct_mq block/blk-core.c:1026 [inline] submit_bio_noacct+0x77d/0x930 block/blk-core.c:1059 submit_bio+0x1f3/0x360 block/blk-core.c:1129 submit_bio_wait+0x79/0xc0 block/bio.c:1154 blkdev_issue_flush+0xc3/0xe0 block/blk-flush.c:450 ext4_sync_file+0x415/0x6c0 fs/ext4/fsync.c:177 vfs_fsync_range+0x107/0x120 fs/sync.c:200 generic_write_sync include/linux/fs.h:2739 [inline] ext4_buffered_write_iter+0x384/0x3d0 fs/ext4/file.c:278 ext4_file_write_iter+0x45e/0x1090 fs/ext4/file.c:503 call_write_iter include/linux/fs.h:1903 [inline] do_iter_readv_writev+0x2cb/0x360 fs/read_write.c:740 do_iter_write+0x112/0x4b0 fs/read_write.c:866 vfs_iter_write+0x4c/0x70 fs/read_write.c:907 iter_file_splice_write+0x42a/0x780 fs/splice.c:686 do_splice_from fs/splice.c:764 [inline] direct_splice_actor+0x80/0xa0 fs/splice.c:933 splice_direct_to_actor+0x345/0x650 fs/splice.c:888 do_splice_direct+0xf5/0x170 fs/splice.c:976 do_sendfile+0x5db/0xca0 fs/read_write.c:1257 __do_sys_sendfile64 fs/read_write.c:1318 [inline] __se_sys_sendfile64 fs/read_write.c:1304 [inline] __x64_sys_sendfile64+0xf2/0x130 fs/read_write.c:1304 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 20888 Comm: syz-executor.1 Not tainted 5.10.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================