commit 4c5f337248303d5f9a5241e15229405e9547fbd3
author senhuang42 <senhuang96@fb.com> Mon Nov 30 15:38:12 2020 -0500
committer senhuang42 <senhuang96@fb.com> Mon Nov 30 15:41:20 2020 -0500
tree a089d946437cd10a033aa84c3185ce792dd39831
parent bcd17db2fbd83adae6f8efd2e55d9cf6e56fd72f

Use cctx's minMatch instead of global MINMATCH, make fuzzer use validation

lib/compress/zstd_compress.c

diff --git a/lib/compress/zstd_compress.c b/lib/compress/zstd_compress.c
index 239af1d..3d09e9f 100644
--- a/lib/compress/zstd_compress.c
+++ b/lib/compress/zstd_compress.c
@@ -4524,7 +4524,7 @@
 
 /* Returns a ZSTD error code if sequence is not valid */
 static size_t ZSTD_validateSequence(U32 offCode, U32 matchLength,
-                                    size_t posInSrc, U32 windowLog, size_t dictSize) {
+                                    size_t posInSrc, U32 windowLog, size_t dictSize, U32 minMatch) {
     size_t offsetBound;
     U32 windowSize = 1 << windowLog;
     /* posInSrc represents the amount of data the the decoder would decode up to this point.
@@ -4534,7 +4534,7 @@
      */
     offsetBound = posInSrc > windowSize ? (size_t)windowSize : posInSrc + (size_t)dictSize;
     RETURN_ERROR_IF(offCode > offsetBound + ZSTD_REP_MOVE, corruption_detected, "Offset too large!");
-    RETURN_ERROR_IF(matchLength < MINMATCH, corruption_detected, "Matchlength too small");
+    RETURN_ERROR_IF(matchLength < minMatch, corruption_detected, "Matchlength too small");
     return 0;
 }
 
@@ -4594,7 +4594,8 @@
         if (cctx->appliedParams.validateSequences) {
             seqPos->posInSrc += litLength + matchLength;
             FORWARD_IF_ERROR(ZSTD_validateSequence(offCode, matchLength, seqPos->posInSrc,
-                                                cctx->appliedParams.cParams.windowLog, dictSize),
+                                                cctx->appliedParams.cParams.windowLog, dictSize,
+                                                cctx->appliedParams.cParams.minMatch),
                                                 "Sequence validation failed");
         }
         ZSTD_storeSeq(&cctx->seqStore, litLength, ip, iend, offCode, matchLength - MINMATCH);
@@ -4716,7 +4717,8 @@
         if (cctx->appliedParams.validateSequences) {
             seqPos->posInSrc += litLength + matchLength;
             FORWARD_IF_ERROR(ZSTD_validateSequence(offCode, matchLength, seqPos->posInSrc,
-                                                   cctx->appliedParams.cParams.windowLog, dictSize),
+                                                   cctx->appliedParams.cParams.windowLog, dictSize,
+                                                   cctx->appliedParams.cParams.minMatch),
                                                    "Sequence validation failed");
         }
         DEBUGLOG(6, "Storing sequence: (of: %u, ml: %u, ll: %u)", offCode, matchLength, litLength);

tests/fuzz/sequence_compression_api.c

diff --git a/tests/fuzz/sequence_compression_api.c b/tests/fuzz/sequence_compression_api.c
index e22c11c..e838687 100644
--- a/tests/fuzz/sequence_compression_api.c
+++ b/tests/fuzz/sequence_compression_api.c
@@ -199,6 +199,7 @@
     ZSTD_CCtx_setParameter(cctx, ZSTD_c_compressionLevel, cLevel);
     ZSTD_CCtx_setParameter(cctx, ZSTD_c_windowLog, wLog);
     ZSTD_CCtx_setParameter(cctx, ZSTD_c_minMatch, ZSTD_MINMATCH_MIN);
+    ZSTD_CCtx_setParameter(cctx, ZSTD_c_validateSequences, 1);
     /* TODO: Add block delim mode fuzzing */
     ZSTD_CCtx_setParameter(cctx, ZSTD_c_blockDelimiters, ZSTD_sf_noBlockDelimiters);
     if (hasDict) {