From add7ed2d4a09c94e5a5b3b80682a858cbb3ecba1 Mon Sep 17 00:00:00 2001 From: Nick Terrell Date: Thu, 14 May 2020 11:50:48 -0700 Subject: [PATCH] [lib] Fix bug in loading LDM dictionary in MT mode Exposed when loading a dictionary < LDM minMatch bytes in MT mode. Test Plan: ``` CC=clang make -j zstreamtest MOREFLAGS="-O0 -fsanitize=address" ./zstreamtest -vv -i100000000 -t1 --newapi -s7065 -t3925297 ``` TODO: Add an explicit test that loads a small dictionary in MT mode --- lib/compress/zstd_compress.c | 2 +- lib/compress/zstd_ldm.c | 12 +++++++----- 2 files changed, 8 insertions(+), 6 deletions(-) diff --git a/lib/compress/zstd_compress.c b/lib/compress/zstd_compress.c index 33c3b4ec..2cfa9305 100644 --- a/lib/compress/zstd_compress.c +++ b/lib/compress/zstd_compress.c @@ -2846,7 +2846,7 @@ static size_t ZSTD_loadDictionaryContent(ZSTD_matchState_t* ms, ZSTD_overflowCorrectIfNeeded(ms, ws, params, ip, ichunk); - if (params->ldmParams.enableLdm && ls != NULL && srcSize >= params->ldmParams.minMatchLength) + if (params->ldmParams.enableLdm && ls != NULL) ZSTD_ldm_fillHashTable(ls, (const BYTE*)src, (const BYTE*)src + srcSize, ¶ms->ldmParams); switch(params->cParams.strategy) diff --git a/lib/compress/zstd_ldm.c b/lib/compress/zstd_ldm.c index 2a1c2cd6..22f36280 100644 --- a/lib/compress/zstd_ldm.c +++ b/lib/compress/zstd_ldm.c @@ -228,11 +228,13 @@ void ZSTD_ldm_fillHashTable( ldmState_t* state, const BYTE* ip, const BYTE* iend, ldmParams_t const* params) { - U64 startingHash = ZSTD_rollingHash_compute(ip, params->minMatchLength); - ZSTD_ldm_fillLdmHashTable( - state, startingHash, ip, iend - params->minMatchLength, state->window.base, - params->hashLog - params->bucketSizeLog, - *params); + if ((size_t)(iend - ip) >= params->minMatchLength) { + U64 startingHash = ZSTD_rollingHash_compute(ip, params->minMatchLength); + ZSTD_ldm_fillLdmHashTable( + state, startingHash, ip, iend - params->minMatchLength, state->window.base, + params->hashLog - params->bucketSizeLog, + *params); + } }