fix bound check for ZSTD_copySequencesToSeqStoreNoBlockDelim()

facebook · Jan 24, 2023 · 7d600c6 · 7d600c6
1 parent 0a91b31
commit 7d600c6
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Showing 3 changed files with 36 additions and 3 deletions.
diff --git a/lib/compress/zstd_compress.c b/lib/compress/zstd_compress.c
@@ -6327,7 +6327,6 @@ ZSTD_copySequencesToSeqStoreNoBlockDelim(ZSTD_CCtx* cctx, ZSTD_sequencePosition*
             /* Move to the next sequence */
             endPosInSequence -= currSeq.litLength + currSeq.matchLength;
             startPosInSequence = 0;
-            idx++;
         } else {
             /* This is the final (partial) sequence we're adding from inSeqs, and endPosInSequence
                does not reach the end of the match. So, we have to split the sequence */
@@ -6382,6 +6381,8 @@ ZSTD_copySequencesToSeqStoreNoBlockDelim(ZSTD_CCtx* cctx, ZSTD_sequencePosition*
                         "Not enough memory allocated. Try adjusting ZSTD_c_minMatch.");
         ZSTD_storeSeq(&cctx->seqStore, litLength, ip, iend, offBase, matchLength);
         ip += matchLength + litLength;
+        if (!finalMatchSplit)
+            idx++; /* Next Sequence */
     }
     DEBUGLOG(5, "Ending seq: idx: %u (of: %u ml: %u ll: %u)", idx, inSeqs[idx].offset, inSeqs[idx].matchLength, inSeqs[idx].litLength);
     assert(idx == inSeqsSize || endPosInSequence <= inSeqs[idx].litLength + inSeqs[idx].matchLength);

diff --git a/tests/fuzz/sequence_compression_api.c b/tests/fuzz/sequence_compression_api.c
@@ -41,8 +41,6 @@ static ZSTD_DDict* ddict = NULL;
 #define ZSTD_FUZZ_MATCHLENGTH_MAXSIZE (1 << 18) /* Allow up to 256KB matches */
 #define ZSTD_FUZZ_GENERATED_DICT_MAXSIZE (1 << ZSTD_WINDOWLOG_MAX_32) /* Allow up to 1 << ZSTD_WINDOWLOG_MAX_32 dictionary */
 #define ZSTD_FUZZ_MAX_NBSEQ (1 << 17) /* Maximum of 128K sequences */
-#define ZSTD_FUZZ_DICT_FILE "sequence_fuzz_dictionary"
-
 
 /* Deterministic random number generator */
 #define FUZZ_RDG_rotl32(x,r) ((x << r) | (x >> (32 - r)))

diff --git a/tests/zstreamtest.c b/tests/zstreamtest.c
@@ -2139,6 +2139,40 @@ static int basicUnitTests(U32 seed, double compressibility, int bigTests)
 
         ZSTD_CCtx_reset(cctx, ZSTD_reset_session_and_parameters);
 
+
+        /* Test with no block delim */
+        {
+            size_t srcSize = 4;
+            void* const src = CNBuffer;
+            size_t dstSize = ZSTD_compressBound(srcSize);
+            void* const dst = compressedBuffer;
+            size_t const kNbSequences = 1;
+            ZSTD_Sequence* sequences = malloc(sizeof(ZSTD_Sequence) * kNbSequences);
+            void* const checkBuf = malloc(srcSize);
+
+            memset(src, 'x', srcSize);
+
+            sequences[0] = (ZSTD_Sequence) {1, 1, 3, 0};
+
+            /* Test with sequence validation */
+            CHECK_Z(ZSTD_CCtx_setParameter(cctx, ZSTD_c_minMatch, 3));
+            CHECK_Z(ZSTD_CCtx_setParameter(cctx, ZSTD_c_blockDelimiters, ZSTD_sf_noBlockDelimiters));
+            CHECK_Z(ZSTD_CCtx_setParameter(cctx, ZSTD_c_validateSequences, 1));
+
+            cSize = ZSTD_compressSequences(cctx, dst, dstSize,
+                                   sequences, kNbSequences,
+                                   src, srcSize);
+
+            CHECK(ZSTD_isError(cSize), "Should not throw an error");
+            CHECK_Z(ZSTD_decompress(checkBuf, srcSize, dst, cSize));
+            CHECK(memcmp(src, checkBuf, srcSize) != 0, "Corruption!");
+
+            free(sequences);
+            free(checkBuf);
+        }
+
+        ZSTD_CCtx_reset(cctx, ZSTD_reset_session_and_parameters);
+
         { /* Test case with two additional sequences */
             size_t srcSize = 19;
             void* const src = CNBuffer;