From ba4beaf6149f7241c8bd85fe853318c2f6837ad0 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sun, 16 Jul 2017 14:57:20 +0200 Subject: [PATCH] avcodec/apedec: Fix integer overflow Fixes: out of array access Fixes: PoC.ape and others Found-by: Bingchang, Liu@VARAS of IIE Signed-off-by: Michael Niedermayer --- libavcodec/apedec.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/libavcodec/apedec.c b/libavcodec/apedec.c index a6b14b8e24..15eb416ba4 100644 --- a/libavcodec/apedec.c +++ b/libavcodec/apedec.c @@ -1412,6 +1412,7 @@ static int ape_decode_frame(AVCodecContext *avctx, void *data, int32_t *sample24; int i, ch, ret; int blockstodecode; + uint64_t decoded_buffer_size; /* this should never be negative, but bad things will happen if it is, so check it just to make sure. */ @@ -1467,7 +1468,7 @@ static int ape_decode_frame(AVCodecContext *avctx, void *data, skip_bits_long(&s->gb, offset); } - if (!nblocks || nblocks > INT_MAX) { + if (!nblocks || nblocks > INT_MAX / 2 / sizeof(*s->decoded_buffer) - 8) { av_log(avctx, AV_LOG_ERROR, "Invalid sample count: %"PRIu32".\n", nblocks); return AVERROR_INVALIDDATA; @@ -1493,8 +1494,9 @@ static int ape_decode_frame(AVCodecContext *avctx, void *data, blockstodecode = s->samples; /* reallocate decoded sample buffer if needed */ - av_fast_malloc(&s->decoded_buffer, &s->decoded_size, - 2 * FFALIGN(blockstodecode, 8) * sizeof(*s->decoded_buffer)); + decoded_buffer_size = 2LL * FFALIGN(blockstodecode, 8) * sizeof(*s->decoded_buffer); + av_assert0(decoded_buffer_size <= INT_MAX); + av_fast_malloc(&s->decoded_buffer, &s->decoded_size, decoded_buffer_size); if (!s->decoded_buffer) return AVERROR(ENOMEM); memset(s->decoded_buffer, 0, s->decoded_size);