detect: fix read overflow in DetectGetLastSMByListId

diff --git a/src/detect-parse.c b/src/detect-parse.c
index 03205a8f0db81bb5351e90e2744feb25211e82d3..08a1e851962615d5716e1e97b082ad541e12c47d 100644 (file)
--- a/src/detect-parse.c
+++ b/src/detect-parse.c
@@ -543,6 +543,9 @@ SigMatch *DetectGetLastSMByListId(const Signature *s, int list_id, ...)
     SigMatch *sm_new;
     int sm_type;
 
+    if ((uint32_t)list_id >= s->init_data->smlists_array_size) {
+        return NULL;
+    }
     SigMatch *sm_list = s->init_data->smlists_tail[list_id];
     if (sm_list == NULL)
         return NULL;