From: Philippe Antoine <pantoine@oisf.net>
Date: Thu, 21 Nov 2024 14:17:21 +0000 (+0100)
Subject: util/streaming-buffer: check need to grow region
X-Git-Tag: suricata-7.0.8~11
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=949bfeca0e5f92212dc3d79f4a87c7c482d376aa;p=thirdparty%2Fsuricata.git

util/streaming-buffer: check need to grow region

Ticket: 7393

As it was possible before earlier patches to get here
with mem_size lesser than start->buf_size,
which caused then an unsigned underflow and a buffer overflow.

(cherry picked from commit 8900041405dbb5f9584edae994af2100733fb4be)
---

diff --git a/src/util-streaming-buffer.c b/src/util-streaming-buffer.c
index b3f5d5d753..9dbaa5f33d 100644
--- a/src/util-streaming-buffer.c
+++ b/src/util-streaming-buffer.c
@@ -940,9 +940,13 @@ static inline void StreamingBufferSlideToOffsetWithRegions(
                     goto done;
                 } else {
                     /* using "main", expand to include "next" */
-                    if (GrowRegionToSize(sb, cfg, start, mem_size) != 0) {
-                        new_mem_size = new_data_size;
-                        goto just_main;
+                    if (mem_size > start->buf_size) {
+                        // Check that start->buf_size is actually not big enough
+                        // As mem_size computation and earlier checks do not make it clear.
+                        if (GrowRegionToSize(sb, cfg, start, mem_size) != 0) {
+                            new_mem_size = new_data_size;
+                            goto just_main;
+                        }
                     }
                     SCLogDebug("start->buf now size %u", mem_size);