From: Karel Zak <kzak@redhat.com>
Date: Fri, 4 Mar 2011 13:44:29 +0000 (+0100)
Subject: umount: segfaults with inconsistent entry in /etc/fstab
X-Git-Tag: v2.20-rc1~489
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=6c7f688b1f46c6fb31aa8a4a27d493c90e9ded37;p=thirdparty%2Futil-linux.git

umount: segfaults with inconsistent entry in /etc/fstab

Addresses: https://bugs.launchpad.net/ubuntu/+source/util-linux/+bug/726283
Reported-by: Greg Brockman <gdb@gregbrockman.com>
Signed-off-by: Karel Zak <kzak@redhat.com>
---

diff --git a/lib/mangle.c b/lib/mangle.c
index 99e8281e62..a5e157bc98 100644
--- a/lib/mangle.c
+++ b/lib/mangle.c
@@ -94,6 +94,8 @@ char *unmangle(const char *s, char **end)
 
 	if (end)
 		*end = e;
+	if (e == s)
+		return NULL;	/* empty string */
 
 	buf = malloc(sz);
 	if (!buf)
diff --git a/mount/mount_mntent.c b/mount/mount_mntent.c
index a1e34db024..d90def36b1 100644
--- a/mount/mount_mntent.c
+++ b/mount/mount_mntent.c
@@ -128,6 +128,9 @@ my_getmntent (mntFILE *mfp) {
 	me.mnt_opts = unmangle(s, &s);
 	s = skip_spaces(s);
 
+	if (!me.mnt_fsname || !me.mnt_dir || !me.mnt_type)
+		goto err;
+
 	if (isdigit(*s)) {
 		me.mnt_freq = atoi(s);
 		while(isdigit(*s)) s++;
diff --git a/mount/umount.c b/mount/umount.c
index 8ef342a521..42671f465e 100644
--- a/mount/umount.c
+++ b/mount/umount.c
@@ -608,7 +608,7 @@ umount_file (char *arg) {
 				     file);
 
 			/* spec could be a file which is loop mounted */
-			if (fs && !is_valid_loop(mc, fs))
+			if (!fs || !is_valid_loop(mc, fs))
 				die (2, _("umount: %s mount disagrees with "
 					  "the fstab"), file);
 		}