ovl: allow filenames with comma

Allow option separator (comma) to be escaped with backslash. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>

ovl: allow filenames with comma
Allow option separator (comma) to be escaped with backslash. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Miklos Szeredi
1 parent 521484639e
Showing 1 changed file with 45 additions and 3 deletions Side-by-side Diff
fs/overlayfs/super.c
@@ -462,11 +462,34 @@
 	{OPT_ERR,			NULL}
 };
  
+static char *ovl_next_opt(char **s)
+{
+	char *sbegin = *s;
+	char *p;
+
+	if (sbegin == NULL)
+		return NULL;
+
+	for (p = sbegin; *p; p++) {
+		if (*p == '\\') {
+			p++;
+			if (!*p)
+				break;
+		} else if (*p == ',') {
+			*p = '\0';
+			*s = p + 1;
+			return sbegin;
+		}
+	}
+	*s = NULL;
+	return sbegin;
+}
+
 static int ovl_parse_opt(char *opt, struct ovl_config *config)
 {
 	char *p;
  
-	while ((p = strsep(&opt, ",")) != NULL) {
+	while ((p = ovl_next_opt(&opt)) != NULL) {
 		int token;
 		substring_t args[MAX_OPT_ARGS];
  
  
  
  
  
@@ -554,15 +577,34 @@
 	goto out_unlock;
 }
  
+static void ovl_unescape(char *s)
+{
+	char *d = s;
+
+	for (;; s++, d++) {
+		if (*s == '\\')
+			s++;
+		*d = *s;
+		if (!*s)
+			break;
+	}
+}
+
 static int ovl_mount_dir(const char *name, struct path *path)
 {
 	int err;
+	char *tmp = kstrdup(name, GFP_KERNEL);
  
-	err = kern_path(name, LOOKUP_FOLLOW, path);
+	if (!tmp)
+		return -ENOMEM;
+
+	ovl_unescape(tmp);
+	err = kern_path(tmp, LOOKUP_FOLLOW, path);
 	if (err) {
-		pr_err("overlayfs: failed to resolve '%s': %i\n", name, err);
+		pr_err("overlayfs: failed to resolve '%s': %i\n", tmp, err);
 		err = -EINVAL;
 	}
+	kfree(tmp);
 	return err;
 }
...	...	@@ -462,11 +462,34 @@
462	462	{OPT_ERR, NULL}
463	463	};
464	464
	465	+static char ovl_next_opt(char *s)
	466	+{
	467	+ char sbegin = s;
	468	+ char *p;
	469	+
	470	+ if (sbegin == NULL)
	471	+ return NULL;
	472	+
	473	+ for (p = sbegin; *p; p++) {
	474	+ if (*p == '\\') {
	475	+ p++;
	476	+ if (!*p)
	477	+ break;
	478	+ } else if (*p == ',') {
	479	+ *p = '\0';
	480	+ *s = p + 1;
	481	+ return sbegin;
	482	+ }
	483	+ }
	484	+ *s = NULL;
	485	+ return sbegin;
	486	+}
	487	+
465	488	static int ovl_parse_opt(char opt, struct ovl_config config)
466	489	{
467	490	char *p;
468	491
469		- while ((p = strsep(&opt, ",")) != NULL) {
	492	+ while ((p = ovl_next_opt(&opt)) != NULL) {
470	493	int token;
471	494	substring_t args[MAX_OPT_ARGS];
472	495
473	496
474	497
475	498
476	499
...	...	@@ -554,15 +577,34 @@
554	577	goto out_unlock;
555	578	}
556	579
	580	+static void ovl_unescape(char *s)
	581	+{
	582	+ char *d = s;
	583	+
	584	+ for (;; s++, d++) {
	585	+ if (*s == '\\')
	586	+ s++;
	587	+ d = s;
	588	+ if (!*s)
	589	+ break;
	590	+ }
	591	+}
	592	+
557	593	static int ovl_mount_dir(const char name, struct path path)
558	594	{
559	595	int err;
	596	+ char *tmp = kstrdup(name, GFP_KERNEL);
560	597
561		- err = kern_path(name, LOOKUP_FOLLOW, path);
	598	+ if (!tmp)
	599	+ return -ENOMEM;
	600	+
	601	+ ovl_unescape(tmp);
	602	+ err = kern_path(tmp, LOOKUP_FOLLOW, path);
562	603	if (err) {
563		- pr_err("overlayfs: failed to resolve '%s': %i\n", name, err);
	604	+ pr_err("overlayfs: failed to resolve '%s': %i\n", tmp, err);
564	605	err = -EINVAL;
565	606	}
	607	+ kfree(tmp);
566	608	return err;
567	609	}
568	610