================================================================== BUG: KCSAN: data-race in ext4_sync_file / writeback_single_inode write to 0xffff88813f234c50 of 8 bytes by task 25221 on cpu 0: writeback_single_inode+0x148/0x3e0 fs/fs-writeback.c:1726 sync_inode_metadata+0x57/0x80 fs/fs-writeback.c:2748 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:2955 [inline] ext4_buffered_write_iter+0x3af/0x400 fs/ext4/file.c:277 ext4_file_write_iter+0x2e7/0x11a0 call_write_iter include/linux/fs.h:2163 [inline] do_iter_readv_writev+0x2cd/0x370 fs/read_write.c:729 do_iter_write+0x192/0x5c0 fs/read_write.c:855 vfs_iter_write+0x4c/0x70 fs/read_write.c:896 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+0x618/0xb90 fs/read_write.c:1249 __do_sys_sendfile64 fs/read_write.c:1314 [inline] __se_sys_sendfile64 fs/read_write.c:1300 [inline] __x64_sys_sendfile64+0xf2/0x130 fs/read_write.c:1300 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae read to 0xffff88813f234c50 of 8 bytes by task 25229 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:2955 [inline] ext4_buffered_write_iter+0x3af/0x400 fs/ext4/file.c:277 ext4_file_write_iter+0x2e7/0x11a0 call_write_iter include/linux/fs.h:2163 [inline] do_iter_readv_writev+0x2cd/0x370 fs/read_write.c:729 do_iter_write+0x192/0x5c0 fs/read_write.c:855 vfs_iter_write+0x4c/0x70 fs/read_write.c:896 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+0x618/0xb90 fs/read_write.c:1249 __do_sys_sendfile64 fs/read_write.c:1314 [inline] __se_sys_sendfile64 fs/read_write.c:1300 [inline] __x64_sys_sendfile64+0xf2/0x130 fs/read_write.c:1300 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae value changed: 0x0000000000000007 -> 0x0000000000000080 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 25229 Comm: syz-executor.5 Not tainted 5.14.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================