misc fixes in libwebpmux

* Assert chunklist
  * fix potential memory leak and
  * fix null pointer access

There should not be several alpha_ or img_ chunks in SynthesizeBitstream. Use ChunkListDelete in MuxImageRelease to be safe.
A null pointer accessed in WebPMuxPushFrame triggered a harmless runtime error.

Change-Id: I3027f8752093652bd41f55e667d041c0de77ab6e
This commit is contained in:
Yannis Guyon
2018-07-04 20:19:47 +02:00
parent e00af13ef4
commit 4338cd36fe
3 changed files with 12 additions and 6 deletions

View File

@@ -400,6 +400,10 @@ static WebPMuxError SynthesizeBitstream(const WebPMuxImage* const wpi,
uint8_t* const data = (uint8_t*)WebPSafeMalloc(1ULL, size);
if (data == NULL) return WEBP_MUX_MEMORY_ERROR;
// There should be at most one alpha_ chunk and exactly one img_ chunk.
assert(wpi->alpha_ == NULL || wpi->alpha_->next_ == NULL);
assert(wpi->img_ != NULL && wpi->img_->next_ == NULL);
// Main RIFF header.
dst = MuxEmitRiffHeader(data, size);