avcodec/wmavoice: sanity check block_align

This limit is roughly based on the bitreader limit, its likely a much tighter limit
could be used

Fixes: left shift of 1965039647 by 1 places cannot be represented in type 'int'
Fixes: 19545/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_WMAVOICE_fuzzer-5695391899320320

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

libavcodec/wmavoice.c

@@ -386,7 +386,7 @@ static av_cold int wmavoice_decode_init(AVCodecContext *ctx)
                ctx->extradata_size);
         return AVERROR_INVALIDDATA;
     }
-    if (ctx->block_align <= 0) {
+    if (ctx->block_align <= 0 || ctx->block_align > (1<<22)) {
         av_log(ctx, AV_LOG_ERROR, "Invalid block alignment %d.\n", ctx->block_align);
         return AVERROR_INVALIDDATA;
     }