[FFmpeg-cvslog] avcodec/mjpegdec: Fix leak in case ICC array allocations fail partially

[Andreas Rheinhardt]

ffmpeg | branch: master | Andreas Rheinhardt <andreas.rheinhardt at outlook.com> | Sat Apr  3 15:39:35 2021 +0200| [a5b2f06b0c69221e375edd918a335c68b33d5667] | committer: Andreas Rheinhardt

avcodec/mjpegdec: Fix leak in case ICC array allocations fail partially

If only one of the two arrays used for the ICC profile could be
successfully allocated, it might be overwritten and leak when
the next ICC entry is encountered. Fix this by using a common struct,
so that one has only one array to allocate.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at outlook.com>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=a5b2f06b0c69221e375edd918a335c68b33d5667
---

 libavcodec/mjpegdec.c | 28 +++++++++++++---------------
 libavcodec/mjpegdec.h |  8 ++++++--
 2 files changed, 19 insertions(+), 17 deletions(-)

diff --git a/libavcodec/mjpegdec.c b/libavcodec/mjpegdec.c
index d0c933b52e..f3d9e99aab 100644
--- a/libavcodec/mjpegdec.c
+++ b/libavcodec/mjpegdec.c
@@ -2088,28 +2088,26 @@ static int mjpeg_decode_app(MJpegDecodeContext *s)
 
         /* Allocate if this is the first APP2 we've seen. */
         if (s->iccnum == 0) {
-            s->iccdata     = av_mallocz(nummarkers * sizeof(*(s->iccdata)));
-            s->iccdatalens = av_mallocz(nummarkers * sizeof(*(s->iccdatalens)));
-            if (!s->iccdata || !s->iccdatalens) {
+            if (!FF_ALLOCZ_TYPED_ARRAY(s->iccentries, nummarkers)) {
                 av_log(s->avctx, AV_LOG_ERROR, "Could not allocate ICC data arrays\n");
                 return AVERROR(ENOMEM);
             }
             s->iccnum = nummarkers;
         }
 
-        if (s->iccdata[seqno - 1]) {
+        if (s->iccentries[seqno - 1].data) {
             av_log(s->avctx, AV_LOG_WARNING, "Duplicate ICC sequence number\n");
             goto out;
         }
 
-        s->iccdatalens[seqno - 1]  = len;
-        s->iccdata[seqno - 1]      = av_malloc(len);
-        if (!s->iccdata[seqno - 1]) {
+        s->iccentries[seqno - 1].length = len;
+        s->iccentries[seqno - 1].data   = av_malloc(len);
+        if (!s->iccentries[seqno - 1].data) {
             av_log(s->avctx, AV_LOG_ERROR, "Could not allocate ICC data buffer\n");
             return AVERROR(ENOMEM);
         }
 
-        memcpy(s->iccdata[seqno - 1], align_get_bits(&s->gb), len);
+        memcpy(s->iccentries[seqno - 1].data, align_get_bits(&s->gb), len);
         skip_bits(&s->gb, len << 3);
         len = 0;
         s->iccread++;
@@ -2318,11 +2316,11 @@ static void reset_icc_profile(MJpegDecodeContext *s)
 {
     int i;
 
-    if (s->iccdata)
+    if (s->iccentries) {
         for (i = 0; i < s->iccnum; i++)
-            av_freep(&s->iccdata[i]);
-    av_freep(&s->iccdata);
-    av_freep(&s->iccdatalens);
+            av_freep(&s->iccentries[i].data);
+        av_freep(&s->iccentries);
+    }
 
     s->iccread = 0;
     s->iccnum  = 0;
@@ -2838,7 +2836,7 @@ the_end:
 
         /* Sum size of all parts. */
         for (i = 0; i < s->iccnum; i++)
-            total_size += s->iccdatalens[i];
+            total_size += s->iccentries[i].length;
 
         sd = av_frame_new_side_data(frame, AV_FRAME_DATA_ICC_PROFILE, total_size);
         if (!sd) {
@@ -2848,8 +2846,8 @@ the_end:
 
         /* Reassemble the parts, which are now in-order. */
         for (i = 0; i < s->iccnum; i++) {
-            memcpy(sd->data + offset, s->iccdata[i], s->iccdatalens[i]);
-            offset += s->iccdatalens[i];
+            memcpy(sd->data + offset, s->iccentries[i].data, s->iccentries[i].length);
+            offset += s->iccentries[i].length;
         }
     }
 
diff --git a/libavcodec/mjpegdec.h b/libavcodec/mjpegdec.h
index 732aeab994..0d69d9101b 100644
--- a/libavcodec/mjpegdec.h
+++ b/libavcodec/mjpegdec.h
@@ -44,6 +44,11 @@
 
 #define MAX_COMPONENTS 4
 
+typedef struct ICCEntry {
+    uint8_t *data;
+    int    length;
+} ICCEntry;
+
 typedef struct MJpegDecodeContext {
     AVClass *class;
     AVCodecContext *avctx;
@@ -138,8 +143,7 @@ typedef struct MJpegDecodeContext {
 
     const AVPixFmtDescriptor *pix_desc;
 
-    uint8_t **iccdata;
-    int *iccdatalens;
+    ICCEntry *iccentries;
     int iccnum;
     int iccread;