avcodec/wmaprodec: Fix cleanup on error

Fixes: memleaks
Fixes: 18023/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_XMA2_fuzzer-5642535011090432

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavcodec/wmaprodec.c

@@ -1888,12 +1888,14 @@ static av_cold int xma_decode_init(AVCodecContext *avctx)
         s->num_streams = avctx->extradata[1];
         if (avctx->extradata_size != (32 + ((avctx->extradata[0]==3)?0:8) + 4*s->num_streams)) {
             av_log(avctx, AV_LOG_ERROR, "Incorrect XMA2 extradata size\n");
+            s->num_streams = 0;
             return AVERROR(EINVAL);
         }
     } else if (avctx->codec_id == AV_CODEC_ID_XMA1 && avctx->extradata_size >= 4) { /* XMAWAVEFORMAT */
         s->num_streams = avctx->extradata[4];
         if (avctx->extradata_size != (8 + 20*s->num_streams)) {
             av_log(avctx, AV_LOG_ERROR, "Incorrect XMA1 extradata size\n");
+            s->num_streams = 0;
             return AVERROR(EINVAL);
         }
     } else {
@@ -1906,6 +1908,7 @@ static av_cold int xma_decode_init(AVCodecContext *avctx)
         s->num_streams <= 0
     ) {
         avpriv_request_sample(avctx, "More than %d channels in %d streams", XMA_MAX_CHANNELS, s->num_streams);
+        s->num_streams = 0;
         return AVERROR_PATCHWELCOME;
     }
 
@@ -1938,6 +1941,7 @@ static av_cold int xma_decode_end(AVCodecContext *avctx)
         decode_end(&s->xma[i]);
         av_frame_free(&s->frames[i]);
     }
+    s->num_streams = 0;
 
     return 0;
 }
@@ -1993,6 +1997,7 @@ AVCodec ff_wmapro_decoder = {
     .close          = wmapro_decode_end,
     .decode         = wmapro_decode_packet,
     .capabilities   = AV_CODEC_CAP_SUBFRAMES | AV_CODEC_CAP_DR1,
+    .caps_internal  = FF_CODEC_CAP_INIT_CLEANUP,
     .flush          = wmapro_flush,
     .sample_fmts    = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,
                                                       AV_SAMPLE_FMT_NONE },
@@ -2008,6 +2013,7 @@ AVCodec ff_xma1_decoder = {
     .close          = xma_decode_end,
     .decode         = xma_decode_packet,
     .capabilities   = AV_CODEC_CAP_SUBFRAMES | AV_CODEC_CAP_DR1 | AV_CODEC_CAP_DELAY,
+    .caps_internal  = FF_CODEC_CAP_INIT_CLEANUP,
     .sample_fmts    = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,
                                                       AV_SAMPLE_FMT_NONE },
 };
@@ -2023,6 +2029,7 @@ AVCodec ff_xma2_decoder = {
     .decode         = xma_decode_packet,
     .flush          = xma_flush,
     .capabilities   = AV_CODEC_CAP_SUBFRAMES | AV_CODEC_CAP_DR1 | AV_CODEC_CAP_DELAY,
+    .caps_internal  = FF_CODEC_CAP_INIT_CLEANUP,
     .sample_fmts    = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,
                                                       AV_SAMPLE_FMT_NONE },
 };