================================================================== BUG: KCSAN: data-race in __writeback_single_inode / ext4_sync_file write to 0xffff88812bafc850 of 8 bytes by task 28268 on cpu 0: __writeback_single_inode+0x1e9/0x450 fs/fs-writeback.c:1503 writeback_single_inode+0x177/0x590 fs/fs-writeback.c:1580 sync_inode fs/fs-writeback.c:2624 [inline] sync_inode_metadata+0x57/0x80 fs/fs-writeback.c:2644 ext4_fsync_nojournal fs/ext4/fsync.c:92 [inline] ext4_sync_file+0x359/0x670 fs/ext4/fsync.c:170 vfs_fsync_range+0x107/0x120 fs/sync.c:200 generic_write_sync include/linux/fs.h:2984 [inline] ext4_buffered_write_iter+0x39c/0x3f0 fs/ext4/file.c:277 ext4_file_write_iter+0x2e7/0x11d0 fs/ext4/file.c:519 call_write_iter include/linux/fs.h:2116 [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+0x773/0xda0 fs/read_write.c:1260 __do_sys_sendfile64 fs/read_write.c:1325 [inline] __se_sys_sendfile64 fs/read_write.c:1311 [inline] __x64_sys_sendfile64+0xf2/0x130 fs/read_write.c:1311 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47 entry_SYSCALL_64_after_hwframe+0x44/0xae read to 0xffff88812bafc850 of 8 bytes by task 28276 on cpu 1: ext4_fsync_nojournal fs/ext4/fsync.c:87 [inline] ext4_sync_file+0x294/0x670 fs/ext4/fsync.c:170 vfs_fsync_range+0x107/0x120 fs/sync.c:200 generic_write_sync include/linux/fs.h:2984 [inline] ext4_buffered_write_iter+0x39c/0x3f0 fs/ext4/file.c:277 ext4_file_write_iter+0x2e7/0x11d0 fs/ext4/file.c:519 call_write_iter include/linux/fs.h:2116 [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+0x773/0xda0 fs/read_write.c:1260 __do_sys_sendfile64 fs/read_write.c:1325 [inline] __se_sys_sendfile64 fs/read_write.c:1311 [inline] __x64_sys_sendfile64+0xf2/0x130 fs/read_write.c:1311 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47 entry_SYSCALL_64_after_hwframe+0x44/0xae Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 28276 Comm: syz-executor.1 Tainted: G W 5.12.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================