[FFmpeg-devel] [PATCH 1/2] avcodec/qtrle: Check remaining bytestream in qtrle_decode_XYbpp()

Michael Niedermayer michael at niedermayer.cc
Mon Jul 30 04:33:29 EEST 2018


Fixes: Timeout
Fixes: 9213/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_QTRLE_fuzzer-5649753332252672

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
---
 libavcodec/qtrle.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/libavcodec/qtrle.c b/libavcodec/qtrle.c
index 670690d0a4..6155b4f3e3 100644
--- a/libavcodec/qtrle.c
+++ b/libavcodec/qtrle.c
@@ -155,6 +155,8 @@ static inline void qtrle_decode_2n4bpp(QtrleContext *s, int row_ptr,
         CHECK_PIXEL_PTR(0);
 
         while ((rle_code = (int8_t)bytestream2_get_byte(&s->g)) != -1) {
+            if (bytestream2_get_bytes_left(&s->g) < 1)
+                return;
             if (rle_code == 0) {
                 /* there's another skip code in the stream */
                 pixel_ptr += (num_pixels * (bytestream2_get_byte(&s->g) - 1));
@@ -210,6 +212,8 @@ static void qtrle_decode_8bpp(QtrleContext *s, int row_ptr, int lines_to_change)
         CHECK_PIXEL_PTR(0);
 
         while ((rle_code = (int8_t)bytestream2_get_byte(&s->g)) != -1) {
+            if (bytestream2_get_bytes_left(&s->g) < 1)
+                return;
             if (rle_code == 0) {
                 /* there's another skip code in the stream */
                 pixel_ptr += (4 * (bytestream2_get_byte(&s->g) - 1));
@@ -259,6 +263,8 @@ static void qtrle_decode_16bpp(QtrleContext *s, int row_ptr, int lines_to_change
         CHECK_PIXEL_PTR(0);
 
         while ((rle_code = (int8_t)bytestream2_get_byte(&s->g)) != -1) {
+            if (bytestream2_get_bytes_left(&s->g) < 1)
+                return;
             if (rle_code == 0) {
                 /* there's another skip code in the stream */
                 pixel_ptr += (bytestream2_get_byte(&s->g) - 1) * 2;
@@ -303,6 +309,8 @@ static void qtrle_decode_24bpp(QtrleContext *s, int row_ptr, int lines_to_change
         CHECK_PIXEL_PTR(0);
 
         while ((rle_code = (int8_t)bytestream2_get_byte(&s->g)) != -1) {
+            if (bytestream2_get_bytes_left(&s->g) < 1)
+                return;
             if (rle_code == 0) {
                 /* there's another skip code in the stream */
                 pixel_ptr += (bytestream2_get_byte(&s->g) - 1) * 3;
@@ -350,6 +358,8 @@ static void qtrle_decode_32bpp(QtrleContext *s, int row_ptr, int lines_to_change
         CHECK_PIXEL_PTR(0);
 
         while ((rle_code = (int8_t)bytestream2_get_byte(&s->g)) != -1) {
+            if (bytestream2_get_bytes_left(&s->g) < 1)
+                return;
             if (rle_code == 0) {
                 /* there's another skip code in the stream */
                 pixel_ptr += (bytestream2_get_byte(&s->g) - 1) * 4;
-- 
2.18.0



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