generic-library/webp
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

handle malloc(0) and calloc(0) uniformly on all platforms

Browse Source 
also change lossless encoder logic, which was relying on explicit
NULL return from WebPSafeMalloc(0)

renamed function to CheckSizeArgumentsOverflow() explicitly

addresses issue #138

Change-Id: Ibbd51cc0281e60e86dfd4c5496274399e4c0f7f3
This commit is contained in:
skal 2013-01-22 10:34:35 +01:00
parent 8189feda50
commit 42f8f9346c
3 changed files with 16 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
src/enc/vp8l.c
View File

@ -221,7 +221,7 @@ static int GetHuffBitLengthsAndCodes(
} }
// Create Huffman trees. // Create Huffman trees.
for (i = 0; i < histogram_image_size; ++i) { for (i = 0; ok && (i < histogram_image_size); ++i) {
HuffmanTreeCode* const codes = &huffman_codes[5 * i]; HuffmanTreeCode* const codes = &huffman_codes[5 * i];
VP8LHistogram* const histo = histogram_image->histograms[i]; VP8LHistogram* const histo = histogram_image->histograms[i];
ok = ok && VP8LCreateHuffmanTree(histo->literal_, 15, codes + 0); ok = ok && VP8LCreateHuffmanTree(histo->literal_, 15, codes + 0);
@ -232,7 +232,11 @@ static int GetHuffBitLengthsAndCodes(
} }
End: End:
if (!ok) free(mem_buf); if (!ok) {
free(mem_buf);
// If one VP8LCreateHuffmanTree() above fails, we need to clean up behind.
memset(huffman_codes, 0, 5 * histogram_image_size * sizeof(*huffman_codes));
}
return ok; return ok;
} }

4
src/utils/huffman_encode.c
View File

@ -188,6 +188,10 @@ static int GenerateOptimalTree(const int* const histogram, int histogram_size,
} }
} }
if (tree_size_orig == 0) { // pretty optimal already!
return 1;
}
// 3 * tree_size is enough to cover all the nodes representing a // 3 * tree_size is enough to cover all the nodes representing a
// population and all the inserted nodes combining two existing nodes. // population and all the inserted nodes combining two existing nodes.
// The tree pool needs 2 * (tree_size_orig - 1) entities, and the // The tree pool needs 2 * (tree_size_orig - 1) entities, and the

11
src/utils/utils.c
View File

@ -19,7 +19,8 @@ extern "C" {
//------------------------------------------------------------------------------ //------------------------------------------------------------------------------
// Checked memory allocation // Checked memory allocation
static int CheckSizeArguments(uint64_t nmemb, size_t size) { // Returns 0 in case of overflow of nmemb * size.
static int CheckSizeArgumentsOverflow(uint64_t nmemb, size_t size) {
const uint64_t total_size = nmemb * size; const uint64_t total_size = nmemb * size;
if (nmemb == 0) return 1; if (nmemb == 0) return 1;
if ((uint64_t)size > WEBP_MAX_ALLOCABLE_MEMORY / nmemb) return 0; if ((uint64_t)size > WEBP_MAX_ALLOCABLE_MEMORY / nmemb) return 0;
@ -28,13 +29,13 @@ static int CheckSizeArguments(uint64_t nmemb, size_t size) {
} }
void* WebPSafeMalloc(uint64_t nmemb, size_t size) { void* WebPSafeMalloc(uint64_t nmemb, size_t size) {
if (!CheckSizeArguments(nmemb, size)) return NULL; if (!CheckSizeArgumentsOverflow(nmemb, size)) return NULL;
return malloc((size_t)(nmemb * size)); return (nmemb > 0 && size > 0) ? malloc((size_t)(nmemb * size)) : NULL;
} }
void* WebPSafeCalloc(uint64_t nmemb, size_t size) { void* WebPSafeCalloc(uint64_t nmemb, size_t size) {
if (!CheckSizeArguments(nmemb, size)) return NULL; if (!CheckSizeArgumentsOverflow(nmemb, size)) return NULL;
return calloc((size_t)nmemb, size); return (nmemb > 0 && size > 0) ? calloc((size_t)nmemb, size) : NULL;
} }
//------------------------------------------------------------------------------ //------------------------------------------------------------------------------