From 4654e1e7381044717d5d3e0dd7e735633a3ff300 Mon Sep 17 00:00:00 2001 From: James Zern Date: Wed, 22 Feb 2023 22:15:47 -0800 Subject: [PATCH] EncodeAlphaInternal: clear result->bw on error This avoids a double free should the function fail prior to VP8BitWriterInit() and a previous trial result's buffer carried over. Previously in ApplyFiltersAndEncode() trial.bw (with a previous iteration's buffer) would be freed, followed by best.bw pointing to the same buffer. Since: 187d379d add a fallback to ALPHA_NO_COMPRESSION In addition, check the return value of VP8BitWriterInit() in this function. Bug: webp:603 Change-Id: Ic258381ee26c8c16bc211d157c8153831c8c6910 (cherry picked from commit a486d800b60d0af4cc0836bf7ed8f21e12974129) --- src/enc/alpha_enc.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/src/enc/alpha_enc.c b/src/enc/alpha_enc.c index f7c02690..7d205586 100644 --- a/src/enc/alpha_enc.c +++ b/src/enc/alpha_enc.c @@ -13,6 +13,7 @@ #include #include +#include #include "src/enc/vp8i_enc.h" #include "src/dsp/dsp.h" @@ -148,6 +149,7 @@ static int EncodeAlphaInternal(const uint8_t* const data, int width, int height, } } else { VP8LBitWriterWipeOut(&tmp_bw); + memset(&result->bw, 0, sizeof(result->bw)); return 0; } } @@ -162,7 +164,7 @@ static int EncodeAlphaInternal(const uint8_t* const data, int width, int height, header = method | (filter << 2); if (reduce_levels) header |= ALPHA_PREPROCESSED_LEVELS << 4; - VP8BitWriterInit(&result->bw, ALPHA_HEADER_LEN + output_size); + if (!VP8BitWriterInit(&result->bw, ALPHA_HEADER_LEN + output_size)) ok = 0; ok = ok && VP8BitWriterAppend(&result->bw, &header, ALPHA_HEADER_LEN); ok = ok && VP8BitWriterAppend(&result->bw, output, output_size);