From 8cc2fa1e5db0655c053b35c948ef05ba0fe13707 Mon Sep 17 00:00:00 2001 From: Janne Grunau Date: Mon, 26 Nov 2012 22:18:31 +0100 Subject: [PATCH] mov: validate number of DataReferenceBox entries against box size Avoids a 2G memory allocation and parsing of random data in mov_read_dref(). The fuzzed sample sample.mp4_s224424 triggers this. --- libavformat/mov.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/libavformat/mov.c b/libavformat/mov.c index a0ede86882..8503a7ebdd 100644 --- a/libavformat/mov.c +++ b/libavformat/mov.c @@ -351,6 +351,7 @@ static int mov_read_chpl(MOVContext *c, AVIOContext *pb, MOVAtom atom) return 0; } +#define MIN_DATA_ENTRY_BOX_SIZE 12 static int mov_read_dref(MOVContext *c, AVIOContext *pb, MOVAtom atom) { AVStream *st; @@ -364,7 +365,8 @@ static int mov_read_dref(MOVContext *c, AVIOContext *pb, MOVAtom atom) avio_rb32(pb); // version + flags entries = avio_rb32(pb); - if (entries >= UINT_MAX / sizeof(*sc->drefs)) + if (entries > (atom.size - 1) / MIN_DATA_ENTRY_BOX_SIZE + 1 || + entries >= UINT_MAX / sizeof(*sc->drefs)) return AVERROR_INVALIDDATA; av_free(sc->drefs); sc->drefs = av_mallocz(entries * sizeof(*sc->drefs));