[PR] avformat/mov: bound iloc/iinf item counts by the box size (PR #24190)

PR #24190 opened by Hawthorn
URL: https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/24190
Patch URL: https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/24190.patch

mov_read_iloc() and mov_read_iinf() read a 16- or 32-bit item/entry
count from the file and pass it straight to av_realloc_array() with no
limit, so a small box can drive a large allocation before the read loop
hits EOF. Reject counts larger than the remaining box size, matching
the existing sgpd bound (a100d346)


>From 7d97eda8bcdea97f8ed3293ce05bd0227bc1b37f Mon Sep 17 00:00:00 2001
From: Hawthorn <[email protected]>
Date: Mon, 17 Aug 2026 20:09:49 +0530
Subject: [PATCH] avformat/mov: bound iloc/iinf item counts by the box size

mov_read_iloc() and mov_read_iinf() read a 16- or 32-bit item/entry
count from the file and pass it straight to av_realloc_array() with no
limit, so a small box can drive a multi-gigabyte allocation before the
read loop hits EOF. Reject counts larger than the remaining box size,
matching the existing sgpd bound.

Signed-off-by: Hawthorn <[email protected]>
---
 libavformat/mov.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/libavformat/mov.c b/libavformat/mov.c
index 5a66d572ee..fcec8d1633 100644
--- a/libavformat/mov.c
+++ b/libavformat/mov.c
@@ -9435,6 +9435,9 @@ static int mov_read_iloc(MOVContext *c, AVIOContext *pb, MOVAtom atom)
     }
     item_count = (version < 2) ? avio_rb16(pb) : avio_rb32(pb);
 
+    if (item_count > atom.size)
+        return AVERROR_INVALIDDATA;
+
     heif_item = av_realloc_array(c->heif_item, FFMAX(item_count, c->nb_heif_item), sizeof(*c->heif_item));
     if (!heif_item)
         return AVERROR(ENOMEM);
@@ -9593,6 +9596,9 @@ static int mov_read_iinf(MOVContext *c, AVIOContext *pb, MOVAtom atom)
     avio_rb24(pb);  // flags.
     entry_count = version ? avio_rb32(pb) : avio_rb16(pb);
 
+    if (entry_count > atom.size)
+        return AVERROR_INVALIDDATA;
+
     heif_item = av_realloc_array(c->heif_item, FFMAX(entry_count, c->nb_heif_item), sizeof(*c->heif_item));
     if (!heif_item)
         return AVERROR(ENOMEM);
-- 
2.52.0

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