[PATCH] xfs_repair: properly detect reserved attribute names

[Eric Sandeen]

This function in xfs_repair tries to make sure that if an attr
name reserved for acls exists in the root namespace, then its
value is a valid acl.

However, because it only compares up to the length of the
reserved name, superstrings may match and cause false positive
xfs_repair errors.

Ensure that both the length and the content match before
flagging it as an error.

Spotted-by: Zach Brown <zab at zabbo.net>
Signed-off-by: Eric Sandeen <sandeen at redhat.com>
---

diff --git a/repair/attr_repair.c b/repair/attr_repair.c
index 27442c4..89a5bbf 100644
--- a/repair/attr_repair.c
+++ b/repair/attr_repair.c
@@ -747,9 +747,10 @@ valuecheck(
 	void *valuep;
 	int clearit = 0;
 
-	if ((strncmp(namevalue, SGI_ACL_FILE, SGI_ACL_FILE_SIZE) == 0) ||
-			(strncmp(namevalue, SGI_ACL_DEFAULT,
-				SGI_ACL_DEFAULT_SIZE) == 0)) {
+	if ((namelen == SGI_ACL_FILE_SIZE &&
+	     strncmp(namevalue, SGI_ACL_FILE, SGI_ACL_FILE_SIZE) == 0) ||
+	    (namelen == SGI_ACL_DEFAULT_SIZE &&
+	     strncmp(namevalue, SGI_ACL_DEFAULT, SGI_ACL_DEFAULT_SIZE) == 0)) {
 		if (value == NULL) {
 			valuep = malloc(valuelen);
 			if (!valuep)