Bound the search and cache key a request can ask

1 file changed, 15 insertions, 0 deletions

diff --git a/source/cache.c b/source/cache.c
index e916728..c6d0427 100644
--- a/source/cache.c
+++ b/source/cache.c
@@ -75,6 +75,15 @@ static int open_slot(struct cache_slot *slot)
 	return 0;
 }
 
+/* A key longer than the buffer above can never be read back, so a slot keyed
+ * on one would never match and every such request would regenerate its page
+ * while still writing a slot nothing can use. Those requests skip the cache
+ * instead. */
+static int key_fits_slot(const char *key)
+{
+	return strlen(key) + 1 <= CACHE_BUFSIZE;
+}
+
 /* Close the active cache slot */
 static int close_slot(struct cache_slot *slot)
 {
@@ -379,6 +388,12 @@ int cache_process(int size, const char *path, const char *key, int ttl,
 	}
 	if (!key)
 		key = "";
+	if (!key_fits_slot(key)) {
+		cache_log("[cgit] Cache key too long for a slot, caching is "
+			  "disabled for this request\n");
+		fn();
+		return 0;
+	}
 	hash = cache_hash_str(key) % size;
 	strbuf_addstr(&filename, path);
 	strbuf_ensure_end(&filename, '/');