[PATCH 2.22 05/14] glob: Fix buffer overflow during GLOB_TILDE unescaping [BZ #22332]

[Raphael Moreira Zinsly <rzinsly@linux.vnet.ibm.com>]

From: Paul Eggert <eggert@cs.ucla.edu>

(cherry picked from commit a159b53fa059947cc2548e3b0d5bdcf7b9630ba8)
---
 ChangeLog    | 6 ++++++
 NEWS         | 4 ++++
 posix/glob.c | 4 ++--
 3 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 7af97cd..4b87910 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.
+
 2017-02-27  Florian Weimer  <fweimer@redhat.com>
 
 	[BZ #21115]
diff --git a/NEWS b/NEWS
index ef34252..314a443 100644
--- a/NEWS
+++ b/NEWS
@@ -71,6 +71,10 @@ Version 2.22.1
 * A use-after-free vulnerability in clntudp_call in the Sun RPC system has been
   fixed (CVE-2017-12133).
 
+* CVE-2017-15804: 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.
+
 \f
 Version 2.22
 
diff --git a/posix/glob.c b/posix/glob.c
index 40496a0..c4c0532 100644
--- a/posix/glob.c
+++ b/posix/glob.c
@@ -839,11 +839,11 @@ glob (pattern, flags, errfunc, pglob)
 		  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
-- 
1.8.3.1