Fix out-of-bounds memory accesses with virtual_root=""
The CGit configuration variable virtual_root is normalized so that it
does not have a trailing '/' character, but it is allowed to be empty
(the empty string and NULL have different meanings here) and there is
code that is insufficiently cautious when checking if it ends in a '/':
if (virtual_root[strlen(virtual_root) - 1] != '/')
Clearly this check is redundant, but rather than simply removing it we
get a slight efficiency improvement by switching the normalization so
that the virtual_root variable always ends in '/'. Do this with a new
"ensure_end" helper.
Signed-off-by: John Keeping <john@keeping.me.uk>
diff --git a/shared.c b/shared.c
index cc06930..1fa9c99 100644
--- a/shared.c
+++ b/shared.c
@@ -115,6 +115,21 @@
return xstrndup(str, len);
}
+char *ensure_end(const char *str, char c)
+{
+ size_t len = strlen(str);
+ char *result;
+
+ if (len && str[len - 1] == c)
+ return xstrndup(str, len);
+
+ result = xmalloc(len + 2);
+ memcpy(result, str, len);
+ result[len] = '/';
+ result[len + 1] = '\0';
+ return result;
+}
+
char *strlpart(char *txt, int maxlen)
{
char *result;