From 380ac5826d3e657a8ce5281d2a69573cb98b6f25 Mon Sep 17 00:00:00 2001
From: Michael Niedermayer <michael@niedermayer.cc>
Date: Tue, 12 Jul 2022 20:43:20 +0200
Subject: [PATCH] avcodec/lagarith: Check dst/src in zero run code

Fixes: out of array access
Fixes: 48799/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_LAGARITH_fuzzer-4764457825337344

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit 9450f759748d02d1d284d2e4afd741cb0fe0c04a)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
---
 libavcodec/lagarith.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/libavcodec/lagarith.c b/libavcodec/lagarith.c
index b0914dc1bc..9957b67b5c 100644
--- a/libavcodec/lagarith.c
+++ b/libavcodec/lagarith.c
@@ -404,6 +404,9 @@ output_zeros:
         if (zero_run) {
             zero_run = 0;
             i += esc_count;
+            if (i >  end - dst ||
+                i >= src_end - src)
+                return AVERROR_INVALIDDATA;
             memcpy(dst, src, i);
             dst += i;
             l->zeros_rem = lag_calc_zero_run(src[i]);