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[FFmpeg-devel] avcodec/exr: Check buf_size more completely

Message ID 20171229020019.13111-1-michael@niedermayer.cc
State Accepted
Commit 903be5e4f66268273dc6e3c42a7fdeaab32066ef
Headers show

Commit Message

Michael Niedermayer Dec. 29, 2017, 2 a.m. UTC 
Fixes: Out of heap array read
Fixes: 4683/clusterfuzz-testcase-minimized-6152313673613312

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
---
 libavcodec/exr.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

Comments

Michael Niedermayer Dec. 30, 2017, 8:01 p.m. UTC | #1 
On Fri, Dec 29, 2017 at 03:00:19AM +0100, Michael Niedermayer wrote:
> Fixes: Out of heap array read
> Fixes: 4683/clusterfuzz-testcase-minimized-6152313673613312
> 
> Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
> Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
> ---
>  libavcodec/exr.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)

applied


[...]
diff mbox

Patch

diff --git a/libavcodec/exr.c b/libavcodec/exr.c
index b1ecde4ebd..454dc74cfb 100644
--- a/libavcodec/exr.c
+++ b/libavcodec/exr.c
@@ -1051,7 +1051,7 @@  static int decode_block(AVCodecContext *avctx, void *tdata,
     line_offset = AV_RL64(s->gb.buffer + jobnr * 8);
 
     if (s->is_tile) {
-        if (line_offset > buf_size - 20)
+        if (buf_size < 20 || line_offset > buf_size - 20)
             return AVERROR_INVALIDDATA;
 
         src  = buf + line_offset + 20;
@@ -1062,7 +1062,7 @@  static int decode_block(AVCodecContext *avctx, void *tdata,
         tile_level_y = AV_RL32(src - 8);
 
         data_size = AV_RL32(src - 4);
-        if (data_size <= 0 || data_size > buf_size)
+        if (data_size <= 0 || data_size > buf_size - line_offset - 20)
             return AVERROR_INVALIDDATA;
 
         if (tile_level_x || tile_level_y) { /* tile level, is not the full res level */
@@ -1095,7 +1095,7 @@  static int decode_block(AVCodecContext *avctx, void *tdata,
         td->channel_line_size = td->xsize * s->current_channel_offset;/* uncompress size of one line */
         uncompressed_size = td->channel_line_size * (uint64_t)td->ysize;/* uncompress size of the block */
     } else {
-        if (line_offset > buf_size - 8)
+        if (buf_size < 8 || line_offset > buf_size - 8)
             return AVERROR_INVALIDDATA;
 
         src  = buf + line_offset + 8;
@@ -1105,7 +1105,7 @@  static int decode_block(AVCodecContext *avctx, void *tdata,
             return AVERROR_INVALIDDATA;
 
         data_size = AV_RL32(src - 4);
-        if (data_size <= 0 || data_size > buf_size)
+        if (data_size <= 0 || data_size > buf_size - line_offset - 8)
             return AVERROR_INVALIDDATA;
 
         td->ysize          = FFMIN(s->scan_lines_per_block, s->ymax - line + 1); /* s->ydelta - line ?? */