[FFmpeg-devel] avcodec/vp9_superframe_split_bsf: Fix integer overflow in frame_size/total_size checks

Submitted by Michael Niedermayer on Dec. 6, 2017, 11:09 p.m.

Details

Message ID 20171206230917.17046-1-michael@niedermayer.cc
State Accepted
Commit eaff5fcb7cde8d1614755269773d471d3a3d1bfc
Headers show

Commit Message

Michael Niedermayer Dec. 6, 2017, 11:09 p.m.
Fixes: signed integer overflow: -1698586465 + -551542752 cannot be represented in type 'int'
Fixes: 4490/clusterfuzz-testcase-minimized-5210014592532480

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
---
 libavcodec/vp9_superframe_split_bsf.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Comments

Michael Niedermayer Dec. 10, 2017, 6:49 p.m.
On Thu, Dec 07, 2017 at 12:09:17AM +0100, Michael Niedermayer wrote:
> Fixes: signed integer overflow: -1698586465 + -551542752 cannot be represented in type 'int'
> Fixes: 4490/clusterfuzz-testcase-minimized-5210014592532480
> 
> Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
> Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
> ---
>  libavcodec/vp9_superframe_split_bsf.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)

applied

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diff --git a/libavcodec/vp9_superframe_split_bsf.c b/libavcodec/vp9_superframe_split_bsf.c
index 6d6d8e664d..0d2523ebf7 100644
--- a/libavcodec/vp9_superframe_split_bsf.c
+++ b/libavcodec/vp9_superframe_split_bsf.c
@@ -59,7 +59,7 @@  static int vp9_superframe_split_filter(AVBSFContext *ctx, AVPacket *out)
 
             if (in->size >= idx_size && in->data[in->size - idx_size] == marker) {
                 GetByteContext bc;
-                int total_size = 0;
+                int64_t total_size = 0;
 
                 bytestream2_init(&bc, in->data + in->size + 1 - idx_size,
                                  nb_frames * length_size);
@@ -70,7 +70,7 @@  static int vp9_superframe_split_filter(AVBSFContext *ctx, AVPacket *out)
                         frame_size |= bytestream2_get_byte(&bc) << (j * 8);
 
                     total_size += frame_size;
-                    if (total_size > in->size - idx_size) {
+                    if (frame_size < 0 || total_size > in->size - idx_size) {
                         av_log(ctx, AV_LOG_ERROR,
                                "Invalid frame size in a superframe: %d\n", frame_size);
                         ret = AVERROR(EINVAL);