================================================================== BUG: KCSAN: data-race in vfs_fsync_range / writeback_single_inode write to 0xffff88810559dcb8 of 4 bytes by task 29194 on cpu 0: writeback_single_inode+0x14f/0x3f0 fs/fs-writeback.c:1776 sync_inode_metadata+0x5c/0x90 fs/fs-writeback.c:2849 generic_buffers_fsync_noflush+0xd8/0x120 fs/buffer.c:610 ext4_fsync_nojournal fs/ext4/fsync.c:88 [inline] ext4_sync_file+0x1ff/0x6c0 fs/ext4/fsync.c:151 vfs_fsync_range+0x116/0x130 fs/sync.c:188 generic_write_sync include/linux/fs.h:2871 [inline] ext4_buffered_write_iter+0x326/0x370 fs/ext4/file.c:305 ext4_file_write_iter+0x293/0xe10 iter_file_splice_write+0x5f1/0x980 fs/splice.c:743 do_splice_from fs/splice.c:941 [inline] direct_splice_actor+0x160/0x2c0 fs/splice.c:1164 splice_direct_to_actor+0x302/0x670 fs/splice.c:1108 do_splice_direct_actor fs/splice.c:1207 [inline] do_splice_direct+0xd7/0x150 fs/splice.c:1233 do_sendfile+0x39b/0x970 fs/read_write.c:1388 __do_sys_sendfile64 fs/read_write.c:1455 [inline] __se_sys_sendfile64 fs/read_write.c:1441 [inline] __x64_sys_sendfile64+0x110/0x150 fs/read_write.c:1441 x64_sys_call+0xed5/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:41 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f read to 0xffff88810559dcb8 of 4 bytes by task 29187 on cpu 1: vfs_fsync_range+0x9a/0x130 fs/sync.c:186 generic_write_sync include/linux/fs.h:2871 [inline] ext4_buffered_write_iter+0x326/0x370 fs/ext4/file.c:305 ext4_file_write_iter+0x293/0xe10 iter_file_splice_write+0x5f1/0x980 fs/splice.c:743 do_splice_from fs/splice.c:941 [inline] direct_splice_actor+0x160/0x2c0 fs/splice.c:1164 splice_direct_to_actor+0x302/0x670 fs/splice.c:1108 do_splice_direct_actor fs/splice.c:1207 [inline] do_splice_direct+0xd7/0x150 fs/splice.c:1233 do_sendfile+0x39b/0x970 fs/read_write.c:1388 __do_sys_sendfile64 fs/read_write.c:1455 [inline] __se_sys_sendfile64 fs/read_write.c:1441 [inline] __x64_sys_sendfile64+0x110/0x150 fs/read_write.c:1441 x64_sys_call+0xed5/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:41 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f value changed: 0x00000038 -> 0x00000002 Reported by Kernel Concurrency Sanitizer on: CPU: 1 UID: 0 PID: 29187 Comm: syz.1.8695 Not tainted 6.12.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 ================================================================== EXT4-fs (loop1): unmounting filesystem 00000000-0000-0000-0000-000000000000.