================================================================== BUG: KCSAN: data-race in relay_switch_subbuf / relay_switch_subbuf write to 0xffff888133aa0238 of 8 bytes by task 22673 on cpu 0: relay_switch_subbuf+0x39d/0x3b0 kernel/relay.c:711 relay_reserve include/linux/relay.h:248 [inline] __blk_add_trace+0x6ba/0x710 kernel/trace/blktrace.c:275 blk_add_trace_plug+0x4a/0x60 kernel/trace/blktrace.c:953 trace_block_plug include/trace/events/block.h:379 [inline] blk_add_rq_to_plug+0x30c/0x390 block/blk-mq.c:2703 blk_mq_submit_bio+0x91c/0xe40 block/blk-mq.c:2856 __submit_bio+0x130/0x330 block/blk-core.c:666 __submit_bio_noacct_mq block/blk-core.c:743 [inline] submit_bio_noacct_nocheck+0x3cb/0x480 block/blk-core.c:760 submit_bio_noacct+0x6c4/0x820 block/blk-core.c:867 submit_bio+0x139/0x150 ext4_io_submit+0x4f/0x60 fs/ext4/page-io.c:378 ext4_writepages+0x94a/0x1970 fs/ext4/inode.c:2824 do_writepages+0x1db/0x350 mm/page-writeback.c:2352 filemap_fdatawrite_wbc+0xd6/0xf0 mm/filemap.c:388 __filemap_fdatawrite_range mm/filemap.c:421 [inline] file_write_and_wait_range+0xd6/0x170 mm/filemap.c:779 ext4_sync_file+0xad/0x560 fs/ext4/fsync.c:151 vfs_fsync_range+0x107/0x120 fs/sync.c:188 generic_write_sync include/linux/fs.h:2732 [inline] ext4_buffered_write_iter+0x23f/0x280 fs/ext4/file.c:277 ext4_file_write_iter+0x211/0xdf0 do_iter_readv_writev+0x27b/0x300 do_iter_write+0x16f/0x5c0 fs/read_write.c:852 vfs_iter_write+0x4c/0x70 fs/read_write.c:893 iter_file_splice_write+0x44a/0x7c0 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+0x345/0x660 fs/splice.c:891 do_splice_direct+0xfb/0x180 fs/splice.c:979 do_sendfile+0x3ad/0x900 fs/read_write.c:1246 __do_sys_sendfile64 fs/read_write.c:1311 [inline] __se_sys_sendfile64 fs/read_write.c:1297 [inline] __x64_sys_sendfile64+0x10c/0x150 fs/read_write.c:1297 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae write to 0xffff888133aa0238 of 8 bytes by task 1406 on cpu 1: relay_switch_subbuf+0x39d/0x3b0 kernel/relay.c:711 relay_reserve include/linux/relay.h:248 [inline] __blk_add_trace+0x6ba/0x710 kernel/trace/blktrace.c:275 blk_add_trace_bio_remap+0x218/0x230 kernel/trace/blktrace.c:1025 trace_block_bio_remap include/trace/events/block.h:479 [inline] blk_partition_remap+0x170/0x1b0 block/blk-core.c:615 submit_bio_noacct+0x378/0x820 block/blk-core.c:801 submit_bio+0x139/0x150 submit_bh_wbc+0x2a8/0x2f0 fs/buffer.c:3045 submit_bh fs/buffer.c:3051 [inline] write_dirty_buffer+0xdb/0xe0 fs/buffer.c:3119 jbd2_journal_commit_transaction+0x5e3/0x2490 fs/jbd2/commit.c:585 kjournald2+0x1af/0x370 fs/jbd2/journal.c:213 kthread+0x1a9/0x1e0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 value changed: 0x0000000000000030 -> 0x0000000000000038 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 1406 Comm: jbd2/sda1-8 Tainted: G W 5.18.0-rc3-syzkaller-00250-g42740a2ff5d3-dirty #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================