avcodec/dxva2_*: Initialize dxva_data_ptr

Related: CID1591888 Uninitialized scalar variable
Related: CID1591925 Uninitialized pointer read
Related: CID1591933 Uninitialized scalar variable

Sponsored-by: Sovereign Tech Fund
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavcodec/dxva2_av1.c

@@ -354,7 +354,7 @@ static int commit_bitstream_and_slice_buffer(AVCodecContext *avctx,
     const AV1DecContext *h = avctx->priv_data;
     AVDXVAContext *ctx = DXVA_CONTEXT(avctx);
     struct av1_dxva2_picture_context *ctx_pic = h->cur_frame.hwaccel_picture_private;
-    void     *dxva_data_ptr;
+    void     *dxva_data_ptr = NULL;
     uint8_t  *dxva_data;
     unsigned dxva_size;
     unsigned padding;
@@ -382,7 +382,7 @@ static int commit_bitstream_and_slice_buffer(AVCodecContext *avctx,
 
     dxva_data = dxva_data_ptr;
 
-    if (ctx_pic->bitstream_size > dxva_size) {
+    if (!dxva_data || ctx_pic->bitstream_size > dxva_size) {
         av_log(avctx, AV_LOG_ERROR, "Bitstream size exceeds hardware buffer");
         return -1;
     }

libavcodec/dxva2_hevc.c

@@ -248,7 +248,7 @@ static int commit_bitstream_and_slice_buffer(AVCodecContext *avctx,
     const HEVCFrame *current_picture = h->cur_frame;
     struct hevc_dxva2_picture_context *ctx_pic = current_picture->hwaccel_picture_private;
     DXVA_Slice_HEVC_Short *slice = NULL;
-    void     *dxva_data_ptr;
+    void     *dxva_data_ptr = NULL;
     uint8_t  *dxva_data, *current, *end;
     unsigned dxva_size;
     void     *slice_data;
@@ -278,6 +278,9 @@ static int commit_bitstream_and_slice_buffer(AVCodecContext *avctx,
     }
 #endif
 
+    if (!dxva_data_ptr)
+        return -1;
+
     dxva_data = dxva_data_ptr;
     current = dxva_data;
     end = dxva_data + dxva_size;

libavcodec/dxva2_mpeg2.c

@@ -160,7 +160,7 @@ static int commit_bitstream_and_slice_buffer(AVCodecContext *avctx,
         s->cur_pic.ptr->hwaccel_picture_private;
     const int is_field = s->picture_structure != PICT_FRAME;
     const unsigned mb_count = s->mb_width * (s->mb_height >> is_field);
-    void     *dxva_data_ptr;
+    void     *dxva_data_ptr = NULL;
     uint8_t  *dxva_data, *current, *end;
     unsigned dxva_size;
     unsigned i;
@@ -186,6 +186,9 @@ static int commit_bitstream_and_slice_buffer(AVCodecContext *avctx,
     }
 #endif
 
+    if (!dxva_data_ptr)
+        return -1;
+
     dxva_data = dxva_data_ptr;
     current = dxva_data;
     end = dxva_data + dxva_size;

libavcodec/dxva2_vc1.c

@@ -197,7 +197,7 @@ static int commit_bitstream_and_slice_buffer(AVCodecContext *avctx,
     const unsigned start_code_size = avctx->codec_id == AV_CODEC_ID_VC1 ? sizeof(start_code) : 0;
     const unsigned mb_count = s->mb_width * (s->mb_height >> v->field_mode);
     DXVA_SliceInfo *slice = NULL;
-    void     *dxva_data_ptr;
+    void     *dxva_data_ptr = NULL;
     uint8_t  *dxva_data, *current, *end;
     unsigned dxva_size;
     unsigned padding;
@@ -224,6 +224,9 @@ static int commit_bitstream_and_slice_buffer(AVCodecContext *avctx,
     }
 #endif
 
+    if (!dxva_data_ptr)
+        return -1;
+
     dxva_data = dxva_data_ptr;
     current = dxva_data;
     end = dxva_data + dxva_size;

libavcodec/dxva2_vp9.c

@@ -172,7 +172,7 @@ static int commit_bitstream_and_slice_buffer(AVCodecContext *avctx,
     const VP9SharedContext *h = avctx->priv_data;
     AVDXVAContext *ctx = DXVA_CONTEXT(avctx);
     struct vp9_dxva2_picture_context *ctx_pic = h->frames[CUR_FRAME].hwaccel_picture_private;
-    void     *dxva_data_ptr;
+    void     *dxva_data_ptr = NULL;
     uint8_t  *dxva_data;
     unsigned dxva_size;
     unsigned padding;
@@ -200,7 +200,7 @@ static int commit_bitstream_and_slice_buffer(AVCodecContext *avctx,
 
     dxva_data = dxva_data_ptr;
 
-    if (ctx_pic->slice.SliceBytesInBuffer > dxva_size) {
+    if (!dxva_data || ctx_pic->slice.SliceBytesInBuffer > dxva_size) {
         av_log(avctx, AV_LOG_ERROR, "Failed to build bitstream");
         return -1;
     }