From 88f2ccdf16b7aa7c47d3683eabcc58ba9a247f24 Mon Sep 17 00:00:00 2001
From: Mark Thompson <sw@jkqxz.net>
Date: Wed, 14 May 2025 21:47:00 +0100
Subject: [PATCH] cbs_apv: Fix memory leak on metadata parse failure

Buffers are allocated inside some metadata types, so we must ensure
that the object is visible to the free function before a parse failure.

Found by libFuzzer.
---
 libavcodec/cbs_apv_syntax_template.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/libavcodec/cbs_apv_syntax_template.c b/libavcodec/cbs_apv_syntax_template.c
index ca66349141..fc8a08ff31 100644
--- a/libavcodec/cbs_apv_syntax_template.c
+++ b/libavcodec/cbs_apv_syntax_template.c
@@ -543,11 +543,11 @@ static int FUNC(metadata)(CodedBitstreamContext *ctx, RWContext *rw,
             return AVERROR_INVALIDDATA;
         }
 
+        current->metadata_count = p + 1;
+
         CHECK(FUNC(metadata_payload)(ctx, rw, pl));
 
         metadata_bytes_left -= pl->payload_size;
-
-        current->metadata_count = p + 1;
         if (metadata_bytes_left == 0)
             break;
     }