From d34a133b78afe2793cd8537f3c7f42437f441e94 Mon Sep 17 00:00:00 2001
From: Diego Biurrun <diego@biurrun.de>
Date: Fri, 11 Aug 2017 19:15:20 +0200
Subject: [PATCH] dfa: Disallow odd width/height and add proper bounds check
for DDS1 chunks
DDS1 chunks are decoded in 2x2 blocks, odd chunk width or height is not
allowed in that case. Also ensure that the decode buffer is big enough
for all blocks being processed.
Bug-Id: CVE-2017-9992
CC: libav-stable@libav.org
---
libavcodec/dfa.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/libavcodec/dfa.c b/libavcodec/dfa.c
index 2654118fad0..1682eb08cdb 100644
--- a/libavcodec/dfa.c
+++ b/libavcodec/dfa.c
@@ -144,6 +144,8 @@ static int decode_dds1(GetByteContext *gb, uint8_t *frame, int width, int height
int mask = 0x10000, bitbuf = 0;
int i, v, offset, count, segments;
+ if ((width | height) & 1)
+ return AVERROR_INVALIDDATA;
segments = bytestream2_get_le16(gb);
while (segments--) {
if (bytestream2_get_bytes_left(gb) < 2)
@@ -171,7 +173,7 @@ static int decode_dds1(GetByteContext *gb, uint8_t *frame, int width, int height
return AVERROR_INVALIDDATA;
frame += v;
} else {
- if (frame_end - frame < width + 3)
+ if (width < 4 || frame_end - frame < width + 4)
return AVERROR_INVALIDDATA;
frame[0] = frame[1] =
frame[width] = frame[width + 1] = bytestream2_get_byte(gb);
--
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