This tries to improve the mac_smack_fix() logic a bit, by properly
handling non-absolute paths.
It's still pretty broken though, which is sad for security technology:
non-normalized paths (for example "/usr/../dev/sda") will still not be
treated correctly. I am not sure how to fix that properly though, and I
don't understand SMACK well enough to do so. This fix hence just fixes
to most obvious glaring issue.
if (!mac_smack_use())
return 0;
- /* Path must be in /dev */
- if (!path_startswith(path, "/dev"))
- return 0;
+ /* Path must be in /dev. Note that this check is pretty sloppy, as we might be called with non-normalized paths
+ * and hence not detect all cases of /dev. */
+
+ if (path_is_absolute(path)) {
+ if (!path_startswith(path, "/dev"))
+ return 0;
+ } else {
+ _cleanup_free_ char *cwd = NULL;
+
+ r = safe_getcwd(&cwd);
+ if (r < 0)
+ return r;
+
+ if (!path_startswith(cwd, "/dev"))
+ return 0;
+ }
fd = open(path, O_NOFOLLOW|O_CLOEXEC|O_PATH);
if (fd < 0) {