From 7ed62bfb46e87a9e878712603469440e6882b184 Mon Sep 17 00:00:00 2001 From: Albert Astals Cid Date: Tue, 28 May 2019 19:35:18 +0200 Subject: [PATCH] Make sure nSelectors is not out of range nSelectors is used in a loop from 0 to nSelectors to access selectorMtf which is UChar selectorMtf[BZ_MAX_SELECTORS]; so if nSelectors is bigger than BZ_MAX_SELECTORS it'll do an invalid memory access Fixes out of bounds access discovered while fuzzying karchive This was reported as CVE-2019-12900 BZ2_decompress in decompress.c in bzip2 through 1.0.6 has an out-of-bounds write when there are many selectors. --- decompress.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/decompress.c b/decompress.c index ab6a624..f3db91d 100644 --- a/decompress.c +++ b/decompress.c @@ -287,7 +287,7 @@ Int32 BZ2_decompress ( DState* s ) GET_BITS(BZ_X_SELECTOR_1, nGroups, 3); if (nGroups < 2 || nGroups > 6) RETURN(BZ_DATA_ERROR); GET_BITS(BZ_X_SELECTOR_2, nSelectors, 15); - if (nSelectors < 1) RETURN(BZ_DATA_ERROR); + if (nSelectors < 1 || nSelectors > BZ_MAX_SELECTORS) RETURN(BZ_DATA_ERROR); for (i = 0; i < nSelectors; i++) { j = 0; while (True) { -- 2.43.5