Protects ZSTD_compressBegin_usingCDict() vs NULL cdict dereference

Will issue an error (GENERIC) is cdict==NULL

diff --git a/lib/compress/zstd_compress.c b/lib/compress/zstd_compress.c
index 8318843be976727244d75388c131554f7df39f03..b3e0b4b3adeea48596ef3e71f155b203b44fc46a 100644 (file)
--- a/lib/compress/zstd_compress.c
+++ b/lib/compress/zstd_compress.c
@@ -2898,6 +2898,7 @@ static ZSTD_parameters ZSTD_getParamsFromCDict(const ZSTD_CDict* cdict) {
 
 size_t ZSTD_compressBegin_usingCDict(ZSTD_CCtx* cctx, const ZSTD_CDict* cdict, unsigned long long pledgedSrcSize)
 {
+    if (cdict==NULL) return ERROR(GENERIC);  /* does not support NULL cdict */
     if (cdict->dictContentSize) CHECK_F(ZSTD_copyCCtx(cctx, cdict->refContext, pledgedSrcSize))
     else {
         ZSTD_parameters params = cdict->refContext->params;
@@ -2916,9 +2917,9 @@ size_t ZSTD_compress_usingCDict(ZSTD_CCtx* cctx,
                                 const void* src, size_t srcSize,
                                 const ZSTD_CDict* cdict)
 {
-    CHECK_F(ZSTD_compressBegin_usingCDict(cctx, cdict, srcSize));
+    CHECK_F(ZSTD_compressBegin_usingCDict(cctx, cdict, srcSize));  /* will check if cdict != NULL */
 
-    if (cdict->refContext->params.fParams.contentSizeFlag==1) {
+    if (cdict->refContext->params.fParams.contentSizeFlag == 1) {
         cctx->params.fParams.contentSizeFlag = 1;
         cctx->frameContentSize = srcSize;
     } else {

diff --git a/lib/zstd.h b/lib/zstd.h
index 4531a84bff16da66e5a7fac59010bed1794039a2..153e244bec2e18a995af5e3f0dd71afbd751e4f6 100644 (file)
--- a/lib/zstd.h
+++ b/lib/zstd.h
@@ -651,7 +651,7 @@ ZSTDLIB_API size_t ZSTD_compressBegin(ZSTD_CCtx* cctx, int compressionLevel);
 ZSTDLIB_API size_t ZSTD_compressBegin_usingDict(ZSTD_CCtx* cctx, const void* dict, size_t dictSize, int compressionLevel);
 ZSTDLIB_API size_t ZSTD_compressBegin_advanced(ZSTD_CCtx* cctx, const void* dict, size_t dictSize, ZSTD_parameters params, unsigned long long pledgedSrcSize); /**< pledgedSrcSize is optional and can be 0 (meaning unknown). note: if the contentSizeFlag is set, pledgedSrcSize == 0 means the source size is actually 0 */
 ZSTDLIB_API size_t ZSTD_copyCCtx(ZSTD_CCtx* cctx, const ZSTD_CCtx* preparedCCtx, unsigned long long pledgedSrcSize); /**<  note: if pledgedSrcSize can be 0, indicating unknown size.  if it is non-zero, it must be accurate.  for 0 size frames, use compressBegin_advanced */
-ZSTDLIB_API size_t ZSTD_compressBegin_usingCDict(ZSTD_CCtx* cctx, const ZSTD_CDict* cdict, unsigned long long pledgedSrcSize); /**< note: if pledgedSrcSize can be 0, indicating unknown size.  if it is non-zero, it must be accurate.  for 0 size frames, use compressBegin_advanced */
+ZSTDLIB_API size_t ZSTD_compressBegin_usingCDict(ZSTD_CCtx* cctx, const ZSTD_CDict* cdict, unsigned long long pledgedSrcSize); /**< note: fail if cdict==NULL. pledgedSrcSize can be 0, indicating unknown size.  For 0 size frames, use compressBegin_advanced */
 ZSTDLIB_API size_t ZSTD_compressContinue(ZSTD_CCtx* cctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
 ZSTDLIB_API size_t ZSTD_compressEnd(ZSTD_CCtx* cctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);