From 07e0f0da240a8538cb9bd2a3719bcacd1138ffff Mon Sep 17 00:00:00 2001
From: Philippe Antoine <contact@catenacyber.fr>
Date: Mon, 9 Oct 2023 14:49:54 +0200
Subject: [PATCH] detect: errors on 65k filestore signatures

Errors when a detection engine gets 65k filestore signatures to
avoid the hard limit to have 65k filestore per signature group
head

Ticket: #6393
(cherry picked from commit db99c45d239d5ca6e805094195f7ae39d3051e44)
---
 src/detect-engine-siggroup.c | 3 +++
 src/detect-filestore.c       | 6 ++++++
 src/detect.h                 | 3 +++
 3 files changed, 12 insertions(+)

diff --git a/src/detect-engine-siggroup.c b/src/detect-engine-siggroup.c
index 67af1c115c..c75a5d0ed8 100644
--- a/src/detect-engine-siggroup.c
+++ b/src/detect-engine-siggroup.c
@@ -48,6 +48,7 @@
 
 #include "util-error.h"
 #include "util-debug.h"
+#include "util-validate.h"
 #include "util-cidr.h"
 #include "util-unittest.h"
 #include "util-unittest-helper.h"
@@ -637,6 +638,8 @@ void SigGroupHeadSetFilestoreCount(DetectEngineCtx *de_ctx, SigGroupHead *sgh)
             continue;
 
         if (SignatureIsFilestoring(s)) {
+            // should be insured by caller that we do not overflow
+            DEBUG_VALIDATE_BUG_ON(sgh->filestore_cnt == UINT16_MAX);
             sgh->filestore_cnt++;
         }
     }
diff --git a/src/detect-filestore.c b/src/detect-filestore.c
index c53a93d78d..03bdbba98c 100644
--- a/src/detect-filestore.c
+++ b/src/detect-filestore.c
@@ -333,6 +333,11 @@ static int DetectFilestoreSetup (DetectEngineCtx *de_ctx, Signature *s, const ch
     static bool warn_not_configured = false;
     static uint32_t de_version = 0;
 
+    if (de_ctx->filestore_cnt == UINT16_MAX) {
+        SCLogError("Cannot have more than 65535 filestore signatures");
+        return -1;
+    }
+
     /* Check on first-time loads (includes following a reload) */
     if (!warn_not_configured || (de_ctx->version != de_version)) {
         if (de_version != de_ctx->version) {
@@ -476,6 +481,7 @@ static int DetectFilestoreSetup (DetectEngineCtx *de_ctx, Signature *s, const ch
     SigMatchAppendSMToList(s, sm, DETECT_SM_LIST_POSTMATCH);
 
     s->flags |= SIG_FLAG_FILESTORE;
+    de_ctx->filestore_cnt++;
 
     if (match)
         pcre2_match_data_free(match);
diff --git a/src/detect.h b/src/detect.h
index 01865454b2..587a29c39d 100644
--- a/src/detect.h
+++ b/src/detect.h
@@ -1039,6 +1039,9 @@ typedef struct DetectEngineCtx_ {
 
     /* Track rule requirements for reporting after loading rules. */
     SCDetectRequiresStatus *requirements;
+
+    /* number of signatures using filestore, limited as u16 */
+    uint16_t filestore_cnt;
 } DetectEngineCtx;
 
 /* Engine groups profiles (low, medium, high, custom) */
-- 
2.47.2