CVE: CVE-2019-9169
Upstream-Status: Backport
Signed-off-by: Ross Burton <ross.burton@intel.com>

From 583dd860d5b833037175247230a328f0050dbfe9 Mon Sep 17 00:00:00 2001
From: Paul Eggert <eggert@cs.ucla.edu>
Date: Mon, 21 Jan 2019 11:08:13 -0800
Subject: [PATCH] regex: fix read overrun [BZ #24114]

Problem found by AddressSanitizer, reported by Hongxu Chen in:
https://debbugs.gnu.org/34140
* posix/regexec.c (proceed_next_node):
Do not read past end of input buffer.
---
 posix/regexec.c |  6 ++++--
 2 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/posix/regexec.c b/posix/regexec.c
index 91d5a79..084b122 100644
--- a/posix/regexec.c
+++ b/posix/regexec.c
@@ -1293,8 +1293,10 @@ proceed_next_node (const re_match_context_t *mctx, Idx nregs, regmatch_t *regs,
 	      else if (naccepted)
 		{
 		  char *buf = (char *) re_string_get_buffer (&mctx->input);
-		  if (memcmp (buf + regs[subexp_idx].rm_so, buf + *pidx,
-			      naccepted) != 0)
+		  if (mctx->input.valid_len - *pidx < naccepted
+		      || (memcmp (buf + regs[subexp_idx].rm_so, buf + *pidx,
+				  naccepted)
+			  != 0))
 		    return -1;
 		}
 	    }
-- 
2.9.3