RBP: 00007f4fd8cec1d0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000018100 R11: 0000000000000246 R12: 0000000000000002
R13: 00007ffd4aa7ae8f R14: 00007f4fd8cec300 R15: 0000000000022000
 </TASK>
==================================================================
BUG: KCSAN: data-race in blk_mq_request_bypass_insert / blk_mq_run_hw_queue

write to 0xffff88810277be10 of 8 bytes by task 277 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 0xffff88810277be10 of 8 bytes by task 10034 on cpu 0:
 list_empty_careful include/linux/list.h:329 [inline]
 blk_mq_hctx_has_pending block/blk-mq.c:100 [inline]
 blk_mq_run_hw_queue+0x19b/0x310 block/blk-mq.c:2091
 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:1269
 blk_finish_plug+0x44/0x60 block/blk-core.c:1293
 ext4_writepages+0x1591/0x1a60 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]
 filemap_write_and_wait_range+0x1b4/0x340 mm/filemap.c:669
 __iomap_dio_rw+0x535/0x10b0 fs/iomap/direct-io.c:561
 iomap_dio_rw+0x38/0x80 fs/iomap/direct-io.c:680
 ext4_dio_read_iter fs/ext4/file.c:77 [inline]
 ext4_file_read_iter+0x190/0x1f0 fs/ext4/file.c:128
 call_read_iter include/linux/fs.h:2068 [inline]
 generic_file_splice_read+0x24f/0x330 fs/splice.c:311
 do_splice_to fs/splice.c:796 [inline]
 splice_direct_to_actor+0x2aa/0x650 fs/splice.c:870
 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: 0xffff88810277be08 -> 0xffff88810277c848

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 10034 Comm: syz-executor.4 Tainted: G        W         5.17.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================