================================================================== BUG: KCSAN: data-race in filemap_read / generic_write_end write to 0xffff8881208c6c08 of 8 bytes by task 3934 on cpu 0: i_size_write include/linux/fs.h:913 [inline] generic_write_end+0x96/0x180 fs/buffer.c:2186 ext4_da_write_end+0x4de/0x630 fs/ext4/inode.c:3062 generic_perform_write+0x261/0x400 mm/filemap.c:3759 ext4_buffered_write_iter+0x25b/0x380 fs/ext4/file.c:269 ext4_file_write_iter+0x2e7/0x1200 call_write_iter include/linux/fs.h:2162 [inline] new_sync_write fs/read_write.c:503 [inline] vfs_write+0x7f5/0x950 fs/read_write.c:590 ksys_write+0xd9/0x190 fs/read_write.c:643 __do_sys_write fs/read_write.c:655 [inline] __se_sys_write fs/read_write.c:652 [inline] __x64_sys_write+0x3e/0x50 fs/read_write.c:652 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 read to 0xffff8881208c6c08 of 8 bytes by task 3943 on cpu 1: i_size_read include/linux/fs.h:891 [inline] filemap_read+0x1f5/0x16d0 mm/filemap.c:2631 generic_file_read_iter+0x72/0x2a0 mm/filemap.c:2784 ext4_file_read_iter+0x1db/0x290 call_read_iter include/linux/fs.h:2156 [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: 0x0000000000003000 -> 0x0000000000006000 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 3943 Comm: syz-executor.5 Not tainted 5.15.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================