File ffmpeg-4-CVE-2026-70628.patch of Package A_tw-ffmpeg-4

From 02fc47e13f903768b75f7985a2706a6223ab4506 Mon Sep 17 00:00:00 2001
From: Michael Niedermayer <michael@niedermayer.cc>
Date: Wed, 22 Jul 2026 05:49:11 +0200
Subject: [PATCH] avcodec/dvbsub_parser: avoid signed overflow in the capacity
 check

Fixes: signed integer overflow
Fixes: out of array access
Fixes: poc.wtv
Fixes: fJeEU9JwKwsR
Found-by: Adrian Junge (vurlo)
(cherry picked from commit 93f2a525ec6c7b467bae68322720d10188fc6e30)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
---
 libavcodec/dvbsub_parser.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavcodec/dvbsub_parser.c b/libavcodec/dvbsub_parser.c
index 4527e4dd75..a93f39bfe0 100644
--- a/libavcodec/dvbsub_parser.c
+++ b/libavcodec/dvbsub_parser.c
@@ -104,7 +104,7 @@ static int dvbsub_parse(AVCodecParserContext *s,
         }
     }
 
-    if (buf_size - buf_pos + pc->packet_index > PARSE_BUF_SIZE)
+    if (buf_size - buf_pos > PARSE_BUF_SIZE - pc->packet_index)
         return buf_size;
 
 /* if not currently in a packet, pass data */
-- 
2.49.0