From: Amir Goldstein <amir73il@gmail.com>
Date: Tue, 11 Jul 2017 12:58:35 +0000 (+0300)
Subject: ovl: fix random return value on mount
X-Git-Tag: v4.12.4~86
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=98cc417e0b95d8cf2baeba5a2159d46be2e0941c;p=thirdparty%2Fkernel%2Fstable.git

ovl: fix random return value on mount

commit 8fc646b44385ff0a9853f6590497e43049eeb311 upstream.

On failure to prepare_creds(), mount fails with a random
return value, as err was last set to an integer cast of
a valid lower mnt pointer or set to 0 if inodes index feature
is enabled.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Fixes: 3fe6e52f0626 ("ovl: override creds with the ones from ...")
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index 4882ffb37baea..04d0c7ed645e3 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -946,6 +946,7 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
 	else
 		sb->s_d_op = &ovl_dentry_operations;
 
+	err = -ENOMEM;
 	ufs->creator_cred = cred = prepare_creds();
 	if (!cred)
 		goto out_put_lower_mnt;