[FFmpeg-cvslog] Fix out of bound reads/writes in the TIFF decoder.
Laurent Aimar
git at videolan.org
Sat Oct 1 02:42:33 CEST 2011
ffmpeg | branch: master | Laurent Aimar <fenrir at videolan.org> | Sat Oct 1 00:45:03 2011 +0200| [5ca5d432e028ffdd4067b87aed6702168c3207b6] | committer: Michael Niedermayer
Fix out of bound reads/writes in the TIFF decoder.
Signed-off-by: Michael Niedermayer <michaelni at gmx.at>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=5ca5d432e028ffdd4067b87aed6702168c3207b6
---
libavcodec/tiff.c | 40 +++++++++++++++++++++++++---------------
1 files changed, 25 insertions(+), 15 deletions(-)
diff --git a/libavcodec/tiff.c b/libavcodec/tiff.c
index 342b0d0..8d0bb98 100644
--- a/libavcodec/tiff.c
+++ b/libavcodec/tiff.c
@@ -213,6 +213,8 @@ static int tiff_unpack_strip(TiffContext *s, uint8_t* dst, int stride, const uin
}
switch(s->compr){
case TIFF_RAW:
+ if (ssrc + size - src < width)
+ return AVERROR_INVALIDDATA;
if (!s->fill_order) {
horizontal_fill(s->bpp, dst, 1, src, 0, width, 0);
} else {
@@ -324,6 +326,8 @@ static int tiff_decode_tag(TiffContext *s, const uint8_t *start, const uint8_t *
uint32_t *pal;
const uint8_t *rp, *gp, *bp;
+ if (end_buf - buf < 12)
+ return -1;
tag = tget_short(&buf, s->le);
type = tget_short(&buf, s->le);
count = tget_long(&buf, s->le);
@@ -383,7 +387,7 @@ static int tiff_decode_tag(TiffContext *s, const uint8_t *start, const uint8_t *
case TIFF_SHORT:
case TIFF_LONG:
s->bpp = 0;
- for(i = 0; i < count; i++) s->bpp += tget(&buf, type, s->le);
+ for(i = 0; i < count && buf < end_buf; i++) s->bpp += tget(&buf, type, s->le);
break;
default:
s->bpp = -1;
@@ -497,6 +501,8 @@ static int tiff_decode_tag(TiffContext *s, const uint8_t *start, const uint8_t *
case TIFF_PAL:
pal = (uint32_t *) s->palette;
off = type_sizes[type];
+ if (count / 3 > 256 || end_buf - buf < count / 3 * off * 3)
+ return -1;
rp = buf;
gp = buf + count / 3 * off;
bp = buf + count / 3 * off * 2;
@@ -540,12 +546,16 @@ static int decode_frame(AVCodecContext *avctx,
AVFrame *picture = data;
AVFrame * const p= (AVFrame*)&s->picture;
const uint8_t *orig_buf = buf, *end_buf = buf + buf_size;
- int id, le, off, ret;
+ unsigned off;
+ int id, le, ret;
int i, j, entries;
- int stride, soff, ssize;
+ int stride;
+ unsigned soff, ssize;
uint8_t *dst;
//parse image header
+ if (end_buf - buf < 8)
+ return AVERROR_INVALIDDATA;
id = AV_RL16(buf); buf += 2;
if(id == 0x4949) le = 1;
else if(id == 0x4D4D) le = 0;
@@ -565,9 +575,9 @@ static int decode_frame(AVCodecContext *avctx,
}
/* parse image file directory */
off = tget_long(&buf, le);
- if(orig_buf + off + 14 >= end_buf){
+ if (off >= UINT_MAX - 14 || end_buf - orig_buf < off + 14) {
av_log(avctx, AV_LOG_ERROR, "IFD offset is greater than image size\n");
- return -1;
+ return AVERROR_INVALIDDATA;
}
buf = orig_buf + off;
entries = tget_short(&buf, le);
@@ -591,23 +601,23 @@ static int decode_frame(AVCodecContext *avctx,
stride = p->linesize[0];
dst = p->data[0];
for(i = 0; i < s->height; i += s->rps){
- if(s->stripsizes)
+ if(s->stripsizes) {
+ if (s->stripsizes >= end_buf)
+ return AVERROR_INVALIDDATA;
ssize = tget(&s->stripsizes, s->sstype, s->le);
- else
+ } else
ssize = s->stripsize;
- if (ssize > buf_size) {
- av_log(avctx, AV_LOG_ERROR, "Buffer size is smaller than strip size\n");
- return -1;
- }
-
if(s->stripdata){
+ if (s->stripdata >= end_buf)
+ return AVERROR_INVALIDDATA;
soff = tget(&s->stripdata, s->sot, s->le);
}else
soff = s->stripoff;
- if (soff < 0) {
- av_log(avctx, AV_LOG_ERROR, "Invalid stripoff: %d\n", soff);
- return AVERROR(EINVAL);
+
+ if (soff > buf_size || ssize > buf_size - soff) {
+ av_log(avctx, AV_LOG_ERROR, "Invalid strip size/offset\n");
+ return -1;
}
if(tiff_unpack_strip(s, dst, stride, orig_buf + soff, ssize, FFMIN(s->rps, s->height - i)) < 0)
break;
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