From acbf987d7bc58d44e554475f0afdc68e971bc494 Mon Sep 17 00:00:00 2001
From: Michael Niedermayer <michael@niedermayer.cc>
Date: Tue, 3 Nov 2026 04:29:28 +0100
Subject: [PATCH] avcodec/tiertexseqv: reject RLE code tables that do not cover
 the block

Found during triage of the security report V9Z2ZdGQsUo6

Fixes: V9Z2ZdGQsUo6
Fixes: use of uninitialized memory
Use of uninitialized memory Replicated through UnModified FFmpeg with MSAN
---
 libavcodec/tiertexseqv.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/libavcodec/tiertexseqv.c b/libavcodec/tiertexseqv.c
index 9a7eb70ee8..c3fee8f0a0 100644
--- a/libavcodec/tiertexseqv.c
+++ b/libavcodec/tiertexseqv.c
@@ -72,6 +72,8 @@ static const unsigned char *seq_unpack_rle_block(const unsigned char *src,
         dst += len;
         dst_size -= len;
     }
+    if (dst_size > 0)
+        return NULL;
     return src;
 }