dfa: improve boundary checks in decode_dds1()

Fixes CVE-2012-2798

CC:libav-stable@libav.org
This commit is contained in:
Anton Khirnov 2012-09-29 13:25:28 +02:00
parent 6a99310fce
commit d05f72c754
1 changed files with 6 additions and 4 deletions

View File

@ -153,8 +153,7 @@ static int decode_dds1(GetByteContext *gb, uint8_t *frame, int width, int height
bitbuf = bytestream2_get_le16u(gb);
mask = 1;
}
if (frame_end - frame < 2)
return AVERROR_INVALIDDATA;
if (bitbuf & mask) {
v = bytestream2_get_le16(gb);
offset = (v & 0x1FFF) << 2;
@ -168,9 +167,12 @@ static int decode_dds1(GetByteContext *gb, uint8_t *frame, int width, int height
frame += 2;
}
} else if (bitbuf & (mask << 1)) {
frame += bytestream2_get_le16(gb) * 2;
v = bytestream2_get_le16(gb)*2;
if (frame - frame_end < v)
return AVERROR_INVALIDDATA;
frame += v;
} else {
if (frame_end - frame < width + 2)
if (frame_end - frame < width + 3)
return AVERROR_INVALIDDATA;
frame[0] = frame[1] =
frame[width] = frame[width + 1] = bytestream2_get_byte(gb);