[FFmpeg-devel] [PATCH 1/6] avcodec/qsvenc: Fix leak and crash when encoding H.264 due to A53_CC

[Andreas Rheinhardt]

Since commit 3bbe0c210b05fc6fbd7b1d4bbd8479db7f2cf957, the Payloads
array of every QSVFrame leaks as soon as the frame is reused;
the leak is small and not very noticeable, but if there is an attempt
to use said array the ensuing crash is much more noticeable.
This happens when encoding H.264 with A53 CC side data.

Furthermore, if said array can not be allocated at all, an AVFrame
leaks.

Fix all of this by not allocating the array separately at all; put it
in QSVFrame instead and restore the Payloads array upon reusing the
frame.

Finally, use av_freep() instead of av_free() to free the payload
entries.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at outlook.com>
---
 libavcodec/qsv_internal.h |  2 ++
 libavcodec/qsvenc.c       | 10 +++-------
 2 files changed, 5 insertions(+), 7 deletions(-)

diff --git a/libavcodec/qsv_internal.h b/libavcodec/qsv_internal.h
index 8090b748b3..fe9d5319c4 100644
--- a/libavcodec/qsv_internal.h
+++ b/libavcodec/qsv_internal.h
@@ -76,6 +76,8 @@ typedef struct QSVFrame {
     mfxExtDecodedFrameInfo dec_info;
     mfxExtBuffer *ext_param;
 
+    mfxPayload *payloads[QSV_MAX_ENC_PAYLOAD]; ///< used for enc_ctrl.Payload
+
     int queued;
     int used;
 
diff --git a/libavcodec/qsvenc.c b/libavcodec/qsvenc.c
index 06f55604b5..66f79bb021 100644
--- a/libavcodec/qsvenc.c
+++ b/libavcodec/qsvenc.c
@@ -1259,7 +1259,7 @@ static void free_encoder_ctrl_payloads(mfxEncodeCtrl* enc_ctrl)
     if (enc_ctrl) {
         int i;
         for (i = 0; i < enc_ctrl->NumPayload && i < QSV_MAX_ENC_PAYLOAD; i++) {
-            av_free(enc_ctrl->Payload[i]);
+            av_freep(&enc_ctrl->Payload[i]);
         }
         enc_ctrl->NumPayload = 0;
     }
@@ -1273,6 +1273,7 @@ static void clear_unused_frames(QSVEncContext *q)
             free_encoder_ctrl_payloads(&cur->enc_ctrl);
             //do not reuse enc_ctrl from previous frame
             memset(&cur->enc_ctrl, 0, sizeof(cur->enc_ctrl));
+            cur->enc_ctrl.Payload = cur->payloads;
             if (cur->frame->format == AV_PIX_FMT_QSV) {
                 av_frame_unref(cur->frame);
             }
@@ -1309,11 +1310,7 @@ static int get_free_frame(QSVEncContext *q, QSVFrame **f)
         av_freep(&frame);
         return AVERROR(ENOMEM);
     }
-    frame->enc_ctrl.Payload = av_mallocz(sizeof(mfxPayload*) * QSV_MAX_ENC_PAYLOAD);
-    if (!frame->enc_ctrl.Payload) {
-        av_freep(&frame);
-        return AVERROR(ENOMEM);
-    }
+    frame->enc_ctrl.Payload = frame->payloads;
     *last = frame;
 
     *f = frame;
@@ -1615,7 +1612,6 @@ int ff_qsv_enc_close(AVCodecContext *avctx, QSVEncContext *q)
     while (cur) {
         q->work_frames = cur->next;
         av_frame_free(&cur->frame);
-        av_free(cur->enc_ctrl.Payload);
         av_freep(&cur);
         cur = q->work_frames;
     }
-- 
2.30.2