[FFmpeg-cvslog] avcodec/tiff: Limit filtering to decoded data

[Michael Niedermayer]

ffmpeg | branch: release/4.1 | Michael Niedermayer <michael at niedermayer.cc> | Fri Nov 23 02:33:04 2018 +0100| [ee349bd0fd5acae9eb3bc142c93aedbf0dffee3c] | committer: Michael Niedermayer

avcodec/tiff: Limit filtering to decoded data

Fixes: Timeout
Fixes: 11068/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_TIFF_fuzzer-5698456681709568

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Reviewed-by: Tomas Härdin <tjoppen at acc.umu.se>
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
(cherry picked from commit 90ac0e5f29ba4730cd92d3268938b3730823e52b)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=ee349bd0fd5acae9eb3bc142c93aedbf0dffee3c
---

 libavcodec/tiff.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/libavcodec/tiff.c b/libavcodec/tiff.c
index b537ec06a5..d5b88923fd 100644
--- a/libavcodec/tiff.c
+++ b/libavcodec/tiff.c
@@ -1304,6 +1304,7 @@ static int decode_frame(AVCodecContext *avctx,
     planes = s->planar ? s->bppcount : 1;
     for (plane = 0; plane < planes; plane++) {
         int remaining = avpkt->size;
+        int decoded_height;
         stride = p->linesize[plane];
         dst = p->data[plane];
         for (i = 0; i < s->height; i += s->rps) {
@@ -1331,6 +1332,8 @@ static int decode_frame(AVCodecContext *avctx,
                 break;
             }
         }
+        decoded_height = FFMIN(i, s->height);
+
         if (s->predictor == 2) {
             if (s->photometric == TIFF_PHOTOMETRIC_YCBCR) {
                 av_log(s->avctx, AV_LOG_ERROR, "predictor == 2 with YUV is unsupported");
@@ -1347,7 +1350,7 @@ static int decode_frame(AVCodecContext *avctx,
                 s->avctx->pix_fmt == AV_PIX_FMT_YA16LE ||
                 s->avctx->pix_fmt == AV_PIX_FMT_GBRP16LE ||
                 s->avctx->pix_fmt == AV_PIX_FMT_GBRAP16LE) {
-                for (i = 0; i < s->height; i++) {
+                for (i = 0; i < decoded_height; i++) {
                     for (j = soff; j < ssize; j += 2)
                         AV_WL16(dst + j, AV_RL16(dst + j) + AV_RL16(dst + j - soff));
                     dst += stride;
@@ -1358,13 +1361,13 @@ static int decode_frame(AVCodecContext *avctx,
                        s->avctx->pix_fmt == AV_PIX_FMT_YA16BE ||
                        s->avctx->pix_fmt == AV_PIX_FMT_GBRP16BE ||
                        s->avctx->pix_fmt == AV_PIX_FMT_GBRAP16BE) {
-                for (i = 0; i < s->height; i++) {
+                for (i = 0; i < decoded_height; i++) {
                     for (j = soff; j < ssize; j += 2)
                         AV_WB16(dst + j, AV_RB16(dst + j) + AV_RB16(dst + j - soff));
                     dst += stride;
                 }
             } else {
-                for (i = 0; i < s->height; i++) {
+                for (i = 0; i < decoded_height; i++) {
                     for (j = soff; j < ssize; j++)
                         dst[j] += dst[j - soff];
                     dst += stride;