ddidderr/zstd-rs
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Refactor dictionary matchfinder index safety check (#4039)

Browse Source
This commit is contained in:
Federico Maresca
2024-05-29 12:35:24 -04:00
committed by GitHub
parent 0e2ceb2d50
commit 5e9a6c2fe4
5 changed files with 24 additions and 18 deletions
Download Patch File Download Diff File Expand all files Collapse all files
lib/compress/zstd_double_fast.c
+4 -4
View File
@@ -392,7 +392,7 @@ size_t ZSTD_compressBlock_doubleFast_dictMatchState_generic(
hashLong[h2] = hashSmall[h] = curr; /* update hash tables */
/* check repcode */
if (((U32)((prefixLowestIndex-1) - repIndex) >= 3 /* intentional underflow */)
if ((ZSTD_index_overlap_check(prefixLowestIndex, repIndex))
&& (MEM_read32(repMatch) == MEM_read32(ip+1)) ) {
const BYTE* repMatchEnd = repIndex < prefixLowestIndex ? dictEnd : iend;
mLength = ZSTD_count_2segments(ip+1+4, repMatch+4, iend, repMatchEnd, prefixLowest) + 4;
@@ -513,7 +513,7 @@ _match_stored:
const BYTE* repMatch2 = repIndex2 < prefixLowestIndex ?
dictBase + repIndex2 - dictIndexDelta :
base + repIndex2;
if ( ((U32)((prefixLowestIndex-1) - (U32)repIndex2) >= 3 /* intentional overflow */)
if ( (ZSTD_index_overlap_check(prefixLowestIndex, repIndex2))
&& (MEM_read32(repMatch2) == MEM_read32(ip)) ) {
const BYTE* const repEnd2 = repIndex2 < prefixLowestIndex ? dictEnd : iend;
size_t const repLength2 = ZSTD_count_2segments(ip+4, repMatch2+4, iend, repEnd2, prefixLowest) + 4;
@@ -651,7 +651,7 @@ size_t ZSTD_compressBlock_doubleFast_extDict_generic(
size_t mLength;
hashSmall[hSmall] = hashLong[hLong] = curr; /* update hash table */
if ((((U32)((prefixStartIndex-1) - repIndex) >= 3) /* intentional underflow : ensure repIndex doesn't overlap dict + prefix */
if (((ZSTD_index_overlap_check(prefixStartIndex, repIndex))
& (offset_1 <= curr+1 - dictStartIndex)) /* note: we are searching at curr+1 */
&& (MEM_read32(repMatch) == MEM_read32(ip+1)) ) {
const BYTE* repMatchEnd = repIndex < prefixStartIndex ? dictEnd : iend;
@@ -719,7 +719,7 @@ size_t ZSTD_compressBlock_doubleFast_extDict_generic(
U32 const current2 = (U32)(ip-base);
U32 const repIndex2 = current2 - offset_2;
const BYTE* repMatch2 = repIndex2 < prefixStartIndex ? dictBase + repIndex2 : base + repIndex2;
if ( (((U32)((prefixStartIndex-1) - repIndex2) >= 3) /* intentional overflow : ensure repIndex2 doesn't overlap dict + prefix */
if ( ((ZSTD_index_overlap_check(prefixStartIndex, repIndex2))
& (offset_2 <= current2 - dictStartIndex))
&& (MEM_read32(repMatch2) == MEM_read32(ip)) ) {
const BYTE* const repEnd2 = repIndex2 < prefixStartIndex ? dictEnd : iend;