From 945e47e2fcc5d1cec693122286da06d8ab829c52 Mon Sep 17 00:00:00 2001
From: "Darrick J. Wong" <darrick.wong@oracle.com>
Date: Thu, 4 Jan 2018 13:58:29 -0600
Subject: [PATCH] xfs_db: fix crash when field list selector string has
 trailing slash

If I run the following command:

xfs_db /dev/sdf -x -c 'agf 0' -c 'addr refcntroot' -c 'addr ptrs[1]\'

it errors out with "bad character in field \" and
then ftok_free crashes on an invalid free() because picking up the
previous token (the closing bracket) xrealloc'd the token array to be 5
elements long but never set the last element's tok pointer.
Consequently the ftok_free tries to free whatever garbage pointer is in
that last element and kaboom.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Eric Sandeen <sandeen@sandeen.net>
[sandeen: slightly clarify commit log]
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
---
 db/flist.c | 1 +
 1 file changed, 1 insertion(+)

Index: xfsprogs-4.5.0/db/flist.c
===================================================================
--- xfsprogs-4.5.0.orig/db/flist.c
+++ xfsprogs-4.5.0/db/flist.c
@@ -400,6 +400,7 @@ flist_split(
 		strncpy(a, s, l);
 		a[l] = '\0';
 		v = xrealloc(v, (nv + 2) * sizeof(*v));
+		v[nv + 1].tok = NULL;
 		v[nv].tok = a;
 		v[nv].tokty = t;
 		nv++;