From: Paul Eggert <eggert@cs.ucla.edu>
Date: Sun, 22 Oct 2017 08:00:57 +0000 (+0200)
Subject: glob: Fix buffer overflow during GLOB_TILDE unescaping [BZ #22332]
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f1cf98b583787cfb6278baea46e286a0ee7567fd;p=thirdparty%2Fglibc.git

glob: Fix buffer overflow during GLOB_TILDE unescaping [BZ #22332]

(cherry picked from commit a159b53fa059947cc2548e3b0d5bdcf7b9630ba8)
---

diff --git a/ChangeLog b/ChangeLog
index 17938167948..0ab08782b4c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2017-10-22  Paul Eggert <eggert@cs.ucla.edu>
+
+	[BZ #22332]
+	* posix/glob.c (__glob): Fix buffer overflow during GLOB_TILDE
+	unescaping.
+
 2017-10-23  Wilco Dijkstra  <wdijkstr@arm.com>
 
 	* malloc/malloc.c (_int_malloc): Add SINGLE_THREAD_P path.
diff --git a/NEWS b/NEWS
index 037b28cb9bb..7d3a326d88e 100644
--- a/NEWS
+++ b/NEWS
@@ -35,6 +35,10 @@ Security related changes:
   processing, leading to a memory leak and, potentially, to a denial
   of service.
 
+  The glob function, when invoked with GLOB_TILDE and without
+  GLOB_NOESCAPE, could write past the end of a buffer while
+  unescaping user names.  Reported by Tim Rühsen.
+
 The following bugs are resolved with this release:
 
   [16750] ldd: Never run file directly.
diff --git a/posix/glob.c b/posix/glob.c
index c761c0861dd..b2273ea7bce 100644
--- a/posix/glob.c
+++ b/posix/glob.c
@@ -850,11 +850,11 @@ glob (const char *pattern, int flags, int (*errfunc) (const char *, int),
 		  char *p = mempcpy (newp, dirname + 1,
 				     unescape - dirname - 1);
 		  char *q = unescape;
-		  while (*q != '\0')
+		  while (q != end_name)
 		    {
 		      if (*q == '\\')
 			{
-			  if (q[1] == '\0')
+			  if (q + 1 == end_name)
 			    {
 			      /* "~fo\\o\\" unescape to user_name "foo\\",
 				 but "~fo\\o\\/" unescape to user_name