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[libzstd] Fix ZSTD_decompressBound() on bad skippable frames 

The function didn't verify that the skippable frame size is correct.
dev
Nick Terrell 2019-04-17 11:14:49 -07:00
parent b85f7d7790
commit 450feb0f95
2 changed files with 8 additions and 1 deletions
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5
lib/decompress/zstd_decompress.c
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@ -467,6 +467,9 @@ static ZSTD_frameSizeInfo ZSTD_findFrameSizeInfo(const void* src, size_t srcSize
if ((srcSize >= ZSTD_SKIPPABLEHEADERSIZE) if ((srcSize >= ZSTD_SKIPPABLEHEADERSIZE)
&& (MEM_readLE32(src) & ZSTD_MAGIC_SKIPPABLE_MASK) == ZSTD_MAGIC_SKIPPABLE_START) { && (MEM_readLE32(src) & ZSTD_MAGIC_SKIPPABLE_MASK) == ZSTD_MAGIC_SKIPPABLE_START) {
frameSizeInfo.compressedSize = readSkippableFrameSize(src, srcSize); frameSizeInfo.compressedSize = readSkippableFrameSize(src, srcSize);
if (frameSizeInfo.compressedSize > srcSize) {
return ZSTD_errorFrameSizeInfo(ERROR(srcSize_wrong));
}
return frameSizeInfo; return frameSizeInfo;
} else { } else {
const BYTE* ip = (const BYTE*)src; const BYTE* ip = (const BYTE*)src;
@ -529,7 +532,6 @@ size_t ZSTD_findFrameCompressedSize(const void *src, size_t srcSize)
return frameSizeInfo.compressedSize; return frameSizeInfo.compressedSize;
} }
/** ZSTD_decompressBound() : /** ZSTD_decompressBound() :
* compatible with legacy mode * compatible with legacy mode
* `src` must point to the start of a ZSTD frame or a skippeable frame * `src` must point to the start of a ZSTD frame or a skippeable frame
@ -546,6 +548,7 @@ unsigned long long ZSTD_decompressBound(const void* src, size_t srcSize)
unsigned long long const decompressedBound = frameSizeInfo.decompressedBound; unsigned long long const decompressedBound = frameSizeInfo.decompressedBound;
if (ZSTD_isError(compressedSize) || decompressedBound == ZSTD_CONTENTSIZE_ERROR) if (ZSTD_isError(compressedSize) || decompressedBound == ZSTD_CONTENTSIZE_ERROR)
return ZSTD_CONTENTSIZE_ERROR; return ZSTD_CONTENTSIZE_ERROR;
assert(srcSize >= compressedSize);
src = (const BYTE*)src + compressedSize; src = (const BYTE*)src + compressedSize;
srcSize -= compressedSize; srcSize -= compressedSize;
bound += decompressedBound; bound += decompressedBound;

4
lib/legacy/zstd_legacy.h
View File

@ -238,6 +238,10 @@ MEM_STATIC ZSTD_frameSizeInfo ZSTD_findFrameSizeInfoLegacy(const void *src, size
frameSizeInfo.decompressedBound = ZSTD_CONTENTSIZE_ERROR; frameSizeInfo.decompressedBound = ZSTD_CONTENTSIZE_ERROR;
break; break;
} }
if (frameSizeInfo.compressedSize > srcSize) {
frameSizeInfo.compressedSize = ERROR(srcSize_wrong);
frameSizeInfo.decompressedBound = ZSTD_CONTENTSIZE_ERROR;
}
return frameSizeInfo; return frameSizeInfo;
} }