diff --git a/module/zstd/lib/compress/zstd_double_fast.c b/module/zstd/lib/compress/zstd_double_fast.c index 27eed66cf..4a95c01a0 100644 --- a/module/zstd/lib/compress/zstd_double_fast.c +++ b/module/zstd/lib/compress/zstd_double_fast.c @@ -409,7 +409,7 @@ static size_t ZSTD_compressBlock_doubleFast_extDict_generic( hashSmall[hSmall] = hashLong[hLong] = current; /* update hash table */ if ((((U32)((prefixStartIndex-1) - repIndex) >= 3) /* intentional underflow : ensure repIndex doesn't overlap dict + prefix */ - & (repIndex > dictStartIndex)) + & (offset_1 < current+1 - dictStartIndex)) /* note: we are searching at current+1 */ && (MEM_read32(repMatch) == MEM_read32(ip+1)) ) { const BYTE* repMatchEnd = repIndex < prefixStartIndex ? dictEnd : iend; mLength = ZSTD_count_2segments(ip+1+4, repMatch+4, iend, repMatchEnd, prefixStart) + 4; @@ -477,7 +477,7 @@ static size_t ZSTD_compressBlock_doubleFast_extDict_generic( 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 */ - & (repIndex2 > dictStartIndex)) + & (offset_2 < current2 - dictStartIndex)) && (MEM_read32(repMatch2) == MEM_read32(ip)) ) { const BYTE* const repEnd2 = repIndex2 < prefixStartIndex ? dictEnd : iend; size_t const repLength2 = ZSTD_count_2segments(ip+4, repMatch2+4, iend, repEnd2, prefixStart) + 4; diff --git a/module/zstd/lib/compress/zstd_fast.c b/module/zstd/lib/compress/zstd_fast.c index 85a3a7a91..17894b854 100644 --- a/module/zstd/lib/compress/zstd_fast.c +++ b/module/zstd/lib/compress/zstd_fast.c @@ -416,9 +416,9 @@ static size_t ZSTD_compressBlock_fast_extDict_generic( const BYTE* const repMatch = repBase + repIndex; hashTable[h] = current; /* update hash table */ DEBUGLOG(7, "offset_1 = %u , current = %u", offset_1, current); - assert(offset_1 <= current +1); /* check repIndex */ - if ( (((U32)((prefixStartIndex-1) - repIndex) >= 3) /* intentional underflow */ & (repIndex > dictStartIndex)) + if ( ( ((U32)((prefixStartIndex-1) - repIndex) >= 3) /* intentional underflow */ + & (offset_1 < current+1 - dictStartIndex) ) /* note: we are searching at current+1 */ && (MEM_read32(repMatch) == MEM_read32(ip+1)) ) { const BYTE* const repMatchEnd = repIndex < prefixStartIndex ? dictEnd : iend; size_t const rLength = ZSTD_count_2segments(ip+1 +4, repMatch +4, iend, repMatchEnd, prefixStart) + 4; @@ -453,7 +453,7 @@ static size_t ZSTD_compressBlock_fast_extDict_generic( U32 const current2 = (U32)(ip-base); U32 const repIndex2 = current2 - offset_2; const BYTE* const repMatch2 = repIndex2 < prefixStartIndex ? dictBase + repIndex2 : base + repIndex2; - if ( (((U32)((prefixStartIndex-1) - repIndex2) >= 3) & (repIndex2 > dictStartIndex)) /* intentional overflow */ + if ( (((U32)((prefixStartIndex-1) - repIndex2) >= 3) & (offset_2 < current - dictStartIndex)) /* intentional overflow */ && (MEM_read32(repMatch2) == MEM_read32(ip)) ) { const BYTE* const repEnd2 = repIndex2 < prefixStartIndex ? dictEnd : iend; size_t const repLength2 = ZSTD_count_2segments(ip+4, repMatch2+4, iend, repEnd2, prefixStart) + 4; diff --git a/module/zstd/lib/compress/zstd_lazy.c b/module/zstd/lib/compress/zstd_lazy.c index 4cf5c88b5..22d80597e 100644 --- a/module/zstd/lib/compress/zstd_lazy.c +++ b/module/zstd/lib/compress/zstd_lazy.c @@ -975,7 +975,8 @@ size_t ZSTD_compressBlock_lazy_extDict_generic( const U32 repIndex = (U32)(current+1 - offset_1); const BYTE* const repBase = repIndex < dictLimit ? dictBase : base; const BYTE* const repMatch = repBase + repIndex; - if (((U32)((dictLimit-1) - repIndex) >= 3) & (repIndex > windowLow)) /* intentional overflow */ + if ( ((U32)((dictLimit-1) - repIndex) >= 3) /* intentional overflow */ + & (offset_1 < current+1 - windowLow) ) /* note: we are searching at current+1 */ if (MEM_read32(ip+1) == MEM_read32(repMatch)) { /* repcode detected we should take it */ const BYTE* const repEnd = repIndex < dictLimit ? dictEnd : iend; @@ -1006,7 +1007,8 @@ size_t ZSTD_compressBlock_lazy_extDict_generic( const U32 repIndex = (U32)(current - offset_1); const BYTE* const repBase = repIndex < dictLimit ? dictBase : base; const BYTE* const repMatch = repBase + repIndex; - if (((U32)((dictLimit-1) - repIndex) >= 3) & (repIndex > windowLow)) /* intentional overflow */ + if ( ((U32)((dictLimit-1) - repIndex) >= 3) /* intentional overflow : do not test positions overlapping 2 memory segments */ + & (offset_1 < current - windowLow) ) /* equivalent to `current > repIndex >= windowLow` */ if (MEM_read32(ip) == MEM_read32(repMatch)) { /* repcode detected */ const BYTE* const repEnd = repIndex < dictLimit ? dictEnd : iend; @@ -1037,7 +1039,8 @@ size_t ZSTD_compressBlock_lazy_extDict_generic( const U32 repIndex = (U32)(current - offset_1); const BYTE* const repBase = repIndex < dictLimit ? dictBase : base; const BYTE* const repMatch = repBase + repIndex; - if (((U32)((dictLimit-1) - repIndex) >= 3) & (repIndex > windowLow)) /* intentional overflow */ + if ( ((U32)((dictLimit-1) - repIndex) >= 3) /* intentional overflow : do not test positions overlapping 2 memory segments */ + & (offset_1 < current - windowLow) ) /* equivalent to `current > repIndex >= windowLow` */ if (MEM_read32(ip) == MEM_read32(repMatch)) { /* repcode detected */ const BYTE* const repEnd = repIndex < dictLimit ? dictEnd : iend; @@ -1083,7 +1086,8 @@ _storeSequence: const U32 repIndex = repCurrent - offset_2; const BYTE* const repBase = repIndex < dictLimit ? dictBase : base; const BYTE* const repMatch = repBase + repIndex; - if (((U32)((dictLimit-1) - repIndex) >= 3) & (repIndex > windowLow)) /* intentional overflow */ + if ( ((U32)((dictLimit-1) - repIndex) >= 3) /* intentional overflow : do not test positions overlapping 2 memory segments */ + & (offset_2 < repCurrent - windowLow) ) /* equivalent to `curr > repIndex >= windowLow` */ if (MEM_read32(ip) == MEM_read32(repMatch)) { /* repcode detected we should take it */ const BYTE* const repEnd = repIndex < dictLimit ? dictEnd : iend;