From abe1e6c568b96bcb382dfa4f61c56d1ab001ea51 Mon Sep 17 00:00:00 2001 From: Karl Williamson Date: Fri, 2 Feb 2018 15:14:27 -0700 Subject: [PATCH] (perl #132227) restart a node if we change to uni rules within the node and encounter a sharp S This could lead to a buffer overflow. (cherry picked from commit a02c70e35d1313a5f4e245e8f863c810e991172d) CVE: CVE-2018-6797 Upstream-Status: Backport [https://perl5.git.perl.org/perl.git/commitdiff/abe1e6c568b96bcb382dfa4f61c56d1ab001ea51] Signed-off-by: Jagadeesh Krishnanjanappa --- regcomp.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/regcomp.c b/regcomp.c index 3b9550b10d..a7dee9a09e 100644 --- a/regcomp.c +++ b/regcomp.c @@ -13543,6 +13543,18 @@ S_regatom(pTHX_ RExC_state_t *pRExC_state, I32 *flagp, U32 depth) * /u. This includes the multi-char fold SHARP S to * 'ss' */ if (UNLIKELY(ender == LATIN_SMALL_LETTER_SHARP_S)) { + + /* If the node started out having uni rules, we + * wouldn't have gotten here. So this means + * something in the middle has changed it, but + * didn't think it needed to reparse. But this + * sharp s now does indicate the need for + * reparsing. */ + if (RExC_uni_semantics) { + p = oldp; + goto loopdone; + } + RExC_seen_unfolded_sharp_s = 1; maybe_exactfu = FALSE; } -- 2.15.1-424-g9478a660812