X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=blobdiff_plain;f=receive-pack.c;h=326749583221d0f5e81f58608a23ab1dc1601177;hb=6bc4c72132adbdc06c428f86a96f27e4f8173b99;hp=fba4cf82353ff43eae7430c863680f481e03dcb0;hpb=c477553b2f4f621216b25800e121af52e0750087;p=git.git

diff --git a/receive-pack.c b/receive-pack.c
index fba4cf823..326749583 100644
--- a/receive-pack.c
+++ b/receive-pack.c
@@ -165,7 +165,8 @@ static const char *update(struct command *cmd)
 	unsigned char *new_sha1 = cmd->new_sha1;
 	struct ref_lock *lock;
 
-	if (!prefixcmp(name, "refs/") && check_ref_format(name + 5)) {
+	/* only refs/... are allowed */
+	if (prefixcmp(name, "refs/") || check_ref_format(name + 5)) {
 		error("refusing to create funny ref '%s' remotely", name);
 		return "funny refname";
 	}
@@ -178,11 +179,21 @@ static const char *update(struct command *cmd)
 	if (deny_non_fast_forwards && !is_null_sha1(new_sha1) &&
 	    !is_null_sha1(old_sha1) &&
 	    !prefixcmp(name, "refs/heads/")) {
+		struct object *old_object, *new_object;
 		struct commit *old_commit, *new_commit;
 		struct commit_list *bases, *ent;
 
-		old_commit = (struct commit *)parse_object(old_sha1);
-		new_commit = (struct commit *)parse_object(new_sha1);
+		old_object = parse_object(old_sha1);
+		new_object = parse_object(new_sha1);
+
+		if (!old_object || !new_object ||
+		    old_object->type != OBJ_COMMIT ||
+		    new_object->type != OBJ_COMMIT) {
+			error("bad sha1 objects for %s", name);
+			return "bad ref";
+		}
+		old_commit = (struct commit *)old_object;
+		new_commit = (struct commit *)new_object;
 		bases = get_merge_bases(old_commit, new_commit, 1);
 		for (ent = bases; ent; ent = ent->next)
 			if (!hashcmp(old_sha1, ent->item->object.sha1))