Fix null pointer addition

diff --git a/lib/compress/zstd_compress.c b/lib/compress/zstd_compress.c
index e9f948170ee1e5013a09a3a6fc467ad14eca6f3d..5dacba8cf129757fc3964b3954f837fe63278972 100644 (file)
--- a/lib/compress/zstd_compress.c
+++ b/lib/compress/zstd_compress.c
@@ -1336,10 +1336,7 @@ ZSTD_reset_matchState(ZSTD_matchState_t* ms,
 
     DEBUGLOG(4, "reset indices : %u", forceResetIndex == ZSTDirp_reset);
     if (forceResetIndex == ZSTDirp_reset) {
-        memset(&ms->window, 0, sizeof(ms->window));
-        ms->window.dictLimit = 1;    /* start from 1, so that 1st position is valid */
-        ms->window.lowLimit = 1;     /* it ensures first and later CCtx usages compress the same */
-        ms->window.nextSrc = ms->window.base + 1;   /* see issue #1241 */
+        ZSTD_window_init(&ms->window);
         ZSTD_cwksp_mark_tables_dirty(ws);
     }
 
@@ -1432,7 +1429,7 @@ static size_t ZSTD_resetCCtx_internal(ZSTD_CCtx* zc,
         size_t const matchStateSize = ZSTD_sizeof_matchState(&params.cParams, /* forCCtx */ 1);
         size_t const maxNbLdmSeq = ZSTD_ldm_getMaxNbSeq(params.ldmParams, blockSize);
 
-        ZSTD_indexResetPolicy_e needsIndexReset = ZSTDirp_continue;
+        ZSTD_indexResetPolicy_e needsIndexReset = zc->initialized ? ZSTDirp_continue : ZSTDirp_reset;
 
         if (ZSTD_indexTooCloseToMax(zc->blockState.matchState.window)) {
             needsIndexReset = ZSTDirp_reset;
@@ -1557,11 +1554,12 @@ static size_t ZSTD_resetCCtx_internal(ZSTD_CCtx* zc,
             zc->ldmSequences = (rawSeq*)ZSTD_cwksp_reserve_aligned(ws, maxNbLdmSeq * sizeof(rawSeq));
             zc->maxNbLdmSequences = maxNbLdmSeq;
 
-            memset(&zc->ldmState.window, 0, sizeof(zc->ldmState.window));
+            ZSTD_window_init(&zc->ldmState.window);
             ZSTD_window_clear(&zc->ldmState.window);
         }
 
         DEBUGLOG(3, "wksp: finished allocating, %zd bytes remain available", ZSTD_cwksp_available_space(ws));
+        zc->initialized = 1;
 
         return 0;
     }
@@ -3757,11 +3755,11 @@ static size_t ZSTD_compressStream_generic(ZSTD_CStream* zcs,
                                           ZSTD_EndDirective const flushMode)
 {
     const char* const istart = (const char*)input->src;
-    const char* const iend = istart + input->size;
-    const char* ip = istart + input->pos;
+    const char* const iend = input->size != 0 ? istart + input->size : istart;
+    const char* ip = input->pos != 0 ? istart + input->pos : istart;
     char* const ostart = (char*)output->dst;
-    char* const oend = ostart + output->size;
-    char* op = ostart + output->pos;
+    char* const oend = output->size != 0 ? ostart + output->size : ostart;
+    char* op = output->pos != 0 ? ostart + output->pos : ostart;
     U32 someMoreWork = 1;
 
     /* check expectations */
@@ -3800,7 +3798,8 @@ static size_t ZSTD_compressStream_generic(ZSTD_CStream* zcs,
                                         zcs->inBuff + zcs->inBuffPos, toLoad,
                                         ip, iend-ip);
                 zcs->inBuffPos += loaded;
-                ip += loaded;
+                if (loaded != 0)
+                    ip += loaded;
                 if ( (flushMode == ZSTD_e_continue)
                   && (zcs->inBuffPos < zcs->inBuffTarget) ) {
                     /* not enough input to fill full block : stop here */
@@ -3860,7 +3859,8 @@ static size_t ZSTD_compressStream_generic(ZSTD_CStream* zcs,
                             zcs->outBuff + zcs->outBuffFlushedSize, toFlush);
                 DEBUGLOG(5, "toFlush: %u into %u ==> flushed: %u",
                             (unsigned)toFlush, (unsigned)(oend-op), (unsigned)flushed);
-                op += flushed;
+                if (flushed)
+                    op += flushed;
                 zcs->outBuffFlushedSize += flushed;
                 if (toFlush!=flushed) {
                     /* flush not fully completed, presumably because dst is too small */

diff --git a/lib/compress/zstd_compress_internal.h b/lib/compress/zstd_compress_internal.h
index 9aec9605fa103f2fd6c5daf8b1101fd0d536e7e1..c76189cc1480ab8edef865bd0e3935168e192ca7 100644 (file)
--- a/lib/compress/zstd_compress_internal.h
+++ b/lib/compress/zstd_compress_internal.h
@@ -249,6 +249,7 @@ struct ZSTD_CCtx_s {
     size_t staticSize;
     SeqCollector seqCollector;
     int isFirstBlock;
+    int initialized;
 
     seqStore_t seqStore;      /* sequences storage ptrs */
     ldmState_t ldmState;      /* long distance matching state */
@@ -858,6 +859,15 @@ ZSTD_checkDictValidity(const ZSTD_window_t* window,
     }   }   }
 }
 
+MEM_STATIC void ZSTD_window_init(ZSTD_window_t* window) {
+    memset(window, 0, sizeof(*window));
+    window->base = (BYTE const*)"";
+    window->dictBase = (BYTE const*)"";
+    window->dictLimit = 1;    /* start from 1, so that 1st position is valid */
+    window->lowLimit = 1;     /* it ensures first and later CCtx usages compress the same */
+    window->nextSrc = window->base + 1;   /* see issue #1241 */
+}
+
 /**
  * ZSTD_window_update():
  * Updates the window by appending [src, src + srcSize) to the window.
@@ -871,6 +881,10 @@ MEM_STATIC U32 ZSTD_window_update(ZSTD_window_t* window,
     BYTE const* const ip = (BYTE const*)src;
     U32 contiguous = 1;
     DEBUGLOG(5, "ZSTD_window_update");
+    if (srcSize == 0)
+        return contiguous;
+    assert(window->base != NULL);
+    assert(window->dictBase != NULL);
     /* Check if blocks follow each other */
     if (src != window->nextSrc) {
         /* not contiguous */

diff --git a/lib/compress/zstd_double_fast.c b/lib/compress/zstd_double_fast.c
index a661a48534dac3850cff49d5f1deb231fb86a5ad..2e657f7c4265f5e5656c3f05b9b1fc169d4e9cc7 100644 (file)
--- a/lib/compress/zstd_double_fast.c
+++ b/lib/compress/zstd_double_fast.c
@@ -96,7 +96,7 @@ size_t ZSTD_compressBlock_doubleFast_generic(
                                      dictCParams->hashLog : hBitsL;
     const U32 dictHBitsS           = dictMode == ZSTD_dictMatchState ?
                                      dictCParams->chainLog : hBitsS;
-    const U32 dictAndPrefixLength  = (U32)(ip - prefixLowest + dictEnd - dictStart);
+    const U32 dictAndPrefixLength  = (U32)((ip - prefixLowest) + (dictEnd - dictStart));
 
     DEBUGLOG(5, "ZSTD_compressBlock_doubleFast_generic");
 
@@ -271,7 +271,7 @@ _match_stored:
                     U32 const repIndex2 = current2 - offset_2;
                     const BYTE* repMatch2 = dictMode == ZSTD_dictMatchState
                         && repIndex2 < prefixLowestIndex ?
-                            dictBase - dictIndexDelta + repIndex2 :
+                            dictBase + repIndex2 - dictIndexDelta :
                             base + repIndex2;
                     if ( ((U32)((prefixLowestIndex-1) - (U32)repIndex2) >= 3 /* intentional overflow */)
                        && (MEM_read32(repMatch2) == MEM_read32(ip)) ) {

diff --git a/lib/compress/zstd_lazy.c b/lib/compress/zstd_lazy.c
index 9ad7e03b54ca0e6ddf27c37bbb77c3acb87e8e50..dd82830eaadbc555d990bc52c19a2efb17a56527 100644 (file)
--- a/lib/compress/zstd_lazy.c
+++ b/lib/compress/zstd_lazy.c
@@ -660,7 +660,7 @@ ZSTD_compressBlock_lazy_generic(
     const U32 dictIndexDelta       = dictMode == ZSTD_dictMatchState ?
                                      prefixLowestIndex - (U32)(dictEnd - dictBase) :
                                      0;
-    const U32 dictAndPrefixLength = (U32)(ip - prefixLowest + dictEnd - dictLowest);
+    const U32 dictAndPrefixLength = (U32)((ip - prefixLowest) + (dictEnd - dictLowest));
 
     /* init */
     ip += (dictAndPrefixLength == 0);

diff --git a/lib/compress/zstdmt_compress.c b/lib/compress/zstdmt_compress.c
index b580d94511ce50053386ffc62d814446ae0960f3..d054256297666252eacc1a723c65735435c7fd98 100644 (file)
--- a/lib/compress/zstdmt_compress.c
+++ b/lib/compress/zstdmt_compress.c
@@ -490,7 +490,7 @@ static int ZSTDMT_serialState_reset(serialState_t* serialState, ZSTDMT_seqPool*
         /* Size the seq pool tables */
         ZSTDMT_setNbSeq(seqPool, ZSTD_ldm_getMaxNbSeq(params.ldmParams, jobSize));
         /* Reset the window */
-        ZSTD_window_clear(&serialState->ldmState.window);
+        ZSTD_window_init(&serialState->ldmState.window);
         serialState->ldmWindow = serialState->ldmState.window;
         /* Resize tables and output space if necessary. */
         if (serialState->ldmState.hashTable == NULL || serialState->params.ldmParams.hashLog < hashLog) {
@@ -1786,7 +1786,7 @@ static int ZSTDMT_isOverlapped(buffer_t buffer, range_t range)
     BYTE const* const bufferStart = (BYTE const*)buffer.start;
     BYTE const* const bufferEnd = bufferStart + buffer.capacity;
     BYTE const* const rangeStart = (BYTE const*)range.start;
-    BYTE const* const rangeEnd = rangeStart + range.size;
+    BYTE const* const rangeEnd = range.size != 0 ? rangeStart + range.size : rangeStart;
 
     if (rangeStart == NULL || bufferStart == NULL)
         return 0;

diff --git a/lib/decompress/zstd_decompress.c b/lib/decompress/zstd_decompress.c
index dd4591b7be9a8bedac2442bafc1bd610e81cb3a6..d4d42e79447f0756c24df65b1792fc74530eb772 100644 (file)
--- a/lib/decompress/zstd_decompress.c
+++ b/lib/decompress/zstd_decompress.c
@@ -618,7 +618,7 @@ static size_t ZSTD_decompressFrame(ZSTD_DCtx* dctx,
 {
     const BYTE* ip = (const BYTE*)(*srcPtr);
     BYTE* const ostart = (BYTE* const)dst;
-    BYTE* const oend = ostart + dstCapacity;
+    BYTE* const oend = dstCapacity != 0 ? ostart + dstCapacity : ostart;
     BYTE* op = ostart;
     size_t remainingSrcSize = *srcSizePtr;
 
@@ -669,7 +669,9 @@ static size_t ZSTD_decompressFrame(ZSTD_DCtx* dctx,
         if (ZSTD_isError(decodedSize)) return decodedSize;
         if (dctx->fParams.checksumFlag)
             XXH64_update(&dctx->xxhState, op, decodedSize);
-        op += decodedSize;
+        if (decodedSize != 0)
+            op += decodedSize;
+        assert(ip != NULL);
         ip += cBlockSize;
         remainingSrcSize -= cBlockSize;
         if (blockProperties.lastBlock) break;
@@ -776,7 +778,8 @@ static size_t ZSTD_decompressMultiFrame(ZSTD_DCtx* dctx,
                 "error.");
             if (ZSTD_isError(res)) return res;
             assert(res <= dstCapacity);
-            dst = (BYTE*)dst + res;
+            if (res != 0)
+                dst = (BYTE*)dst + res;
             dstCapacity -= res;
         }
         moreThan1Frame = 1;
@@ -1486,11 +1489,13 @@ MEM_STATIC size_t ZSTD_limitCopy(void* dst, size_t dstCapacity, const void* src,
 
 size_t ZSTD_decompressStream(ZSTD_DStream* zds, ZSTD_outBuffer* output, ZSTD_inBuffer* input)
 {
-    const char* const istart = (const char*)(input->src) + input->pos;
-    const char* const iend = (const char*)(input->src) + input->size;
+    const char* const src = (const char*)input->src;
+    const char* const istart = input->pos != 0 ? src + input->pos : src;
+    const char* const iend = input->size != 0 ? src + input->size : src;
     const char* ip = istart;
-    char* const ostart = (char*)(output->dst) + output->pos;
-    char* const oend = (char*)(output->dst) + output->size;
+    char* const dst = (char*)output->dst;
+    char* const ostart = output->pos != 0 ? dst + output->pos : dst;
+    char* const oend = output->size != 0 ? dst + output->size : dst;
     char* op = ostart;
     U32 someMoreWork = 1;
 

diff --git a/tests/fuzzer.c b/tests/fuzzer.c
index 427dbff193ccf201da43c4903f5daa8167f09832..a59916446960f49cb12d0c305f073010de70626a 100644 (file)
--- a/tests/fuzzer.c
+++ b/tests/fuzzer.c
@@ -490,6 +490,19 @@ static int basicUnitTests(U32 const seed, double compressibility)
     }
     DISPLAYLEVEL(3, "OK \n");
 
+    DISPLAYLEVEL(3, "test%3i : compress a NULL input with each level : ", testNb++);
+    {   int level = -1;
+        ZSTD_CCtx* cctx = ZSTD_createCCtx();
+        if (!cctx) goto _output_error;
+        for (level = -1; level <= ZSTD_maxCLevel(); ++level) {
+          CHECK_Z( ZSTD_compress(compressedBuffer, compressedBufferSize, NULL, 0, level) );
+          CHECK_Z( ZSTD_CCtx_setParameter(cctx, ZSTD_c_compressionLevel, level) );
+          CHECK_Z( ZSTD_compress2(cctx, compressedBuffer, compressedBufferSize, NULL, 0) );
+        }
+        ZSTD_freeCCtx(cctx);
+    }
+    DISPLAYLEVEL(3, "OK \n");
+
     DISPLAYLEVEL(3, "test%3d : check CCtx size after compressing empty input : ", testNb++);
     {   ZSTD_CCtx* const cctx = ZSTD_createCCtx();
         size_t const r = ZSTD_compressCCtx(cctx, compressedBuffer, compressedBufferSize, NULL, 0, 19);

diff --git a/tests/zstreamtest.c b/tests/zstreamtest.c
index 2047d4bd85ccdc66f71d07de13d58ace0f145275..549a4981bbbb47feef461a4828e2f18e3af9873e 100644 (file)
--- a/tests/zstreamtest.c
+++ b/tests/zstreamtest.c
@@ -509,6 +509,33 @@ static int basicUnitTests(U32 seed, double compressibility)
     }
     DISPLAYLEVEL(3, "OK \n");
 
+    DISPLAYLEVEL(3, "test%3i : NULL buffers : ", testNb++);
+    inBuff.src = NULL;
+    inBuff.size = 0;
+    inBuff.pos = 0;
+    outBuff.dst = NULL;
+    outBuff.size = 0;
+    outBuff.pos = 0;
+    CHECK_Z( ZSTD_compressStream(zc, &outBuff, &inBuff) );
+    CHECK(inBuff.pos != inBuff.size, "Entire input should be consumed");
+    CHECK_Z( ZSTD_endStream(zc, &outBuff) );
+    outBuff.dst = (char*)(compressedBuffer);
+    outBuff.size = compressedBufferSize;
+    outBuff.pos = 0;
+    {   size_t const r = ZSTD_endStream(zc, &outBuff);
+        CHECK(r != 0, "Error or some data not flushed (ret=%zu)", r);
+    }
+    inBuff.src = outBuff.dst;
+    inBuff.size = outBuff.pos;
+    inBuff.pos = 0;
+    outBuff.dst = NULL;
+    outBuff.size = 0;
+    outBuff.pos = 0;
+    CHECK_Z( ZSTD_initDStream(zd) );
+    {   size_t const ret = ZSTD_decompressStream(zd, &outBuff, &inBuff);
+        if (ret != 0) goto _output_error;
+    }
+    DISPLAYLEVEL(3, "OK\n");
     /* _srcSize compression test */
     DISPLAYLEVEL(3, "test%3i : compress_srcSize %u bytes : ", testNb++, COMPRESSIBLE_NOISE_LENGTH);
     CHECK_Z( ZSTD_initCStream_srcSize(zc, 1, CNBufferSize) );