file_utils: harden lxc_writeat()

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

diff --git a/src/lxc/file_utils.c b/src/lxc/file_utils.c
index 2fd81d6e232ef72db056f76ef9b3749b581c98d9..d871190d7678796f8ccc6713477d491956653d8e 100644 (file)
--- a/src/lxc/file_utils.c
+++ b/src/lxc/file_utils.c
@@ -47,8 +47,7 @@ int lxc_writeat(int dirfd, const char *filename, const void *buf, size_t count)
        __do_close int fd = -EBADF;
        ssize_t ret;
 
-       fd = openat(dirfd, filename,
-                   O_WRONLY | O_CLOEXEC | O_NOCTTY | O_NOFOLLOW);
+       fd = open_at(dirfd, filename, PROTECT_OPEN_W_WITH_TRAILING_SYMLINKS, PROTECT_LOOKUP_BENEATH, 0);
        if (fd < 0)
                return -1;