From 6aad0b1bb54d6a5d0367ec3b127476f5516ed618 Mon Sep 17 00:00:00 2001
From: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
Date: Sat, 3 Apr 2021 15:39:35 +0200
Subject: [PATCH] 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@outlook.com>
(cherry picked from commit 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 e4e0c26df9..2df6caa440 100644
--- a/libavcodec/mjpegdec.c
+++ b/libavcodec/mjpegdec.c
@@ -2087,28 +2087,26 @@ 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++;
@@ -2317,11 +2315,11 @@ 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;
@@ -2837,7 +2835,7 @@ 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) {
@@ -2847,8 +2845,8 @@ 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;