Received-SPF: pass (google.com: domain of linux-ext4-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
From:   Chengguang Xu <cgxu519@mykernel.net>
To:     jack@suse.com
Cc:     linux-ext4@vger.kernel.org, Chengguang Xu <cgxu519@mykernel.net>
Message-ID: <20200603084429.25344-1-cgxu519@mykernel.net>
Subject: [PATCH] ext2: fix improper assignment for e_value_offs
Date:   Wed,  3 Jun 2020 16:44:29 +0800
MIME-Version: 1.0
Content-Transfer-Encoding: quoted-printable
Content-Type: text/plain; charset=utf8
Sender: linux-ext4-owner@vger.kernel.org
Precedence: bulk

In the process of changing value for existing EA,
there is an improper assignment of e_value_offs(setting to 0),
because it will be reset to incorrect value in the following
loop(shifting EA values before target). Delayed assignment
can avoid this issue.

Signed-off-by: Chengguang Xu <cgxu519@mykernel.net>
---
 fs/ext2/xattr.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/ext2/xattr.c b/fs/ext2/xattr.c
index 943cc469f42f..c802ea682e7f 100644
--- a/fs/ext2/xattr.c
+++ b/fs/ext2/xattr.c
@@ -588,7 +588,6 @@ ext2_xattr_set(struct inode *inode, int name_index, con=
st char *name,
 =09=09=09/* Remove the old value. */
 =09=09=09memmove(first_val + size, first_val, val - first_val);
 =09=09=09memset(first_val, 0, size);
-=09=09=09here->e_value_offs =3D 0;
 =09=09=09min_offs +=3D size;
=20
 =09=09=09/* Adjust all value offsets. */
@@ -600,6 +599,8 @@ ext2_xattr_set(struct inode *inode, int name_index, con=
st char *name,
 =09=09=09=09=09=09cpu_to_le16(o + size);
 =09=09=09=09last =3D EXT2_XATTR_NEXT(last);
 =09=09=09}
+
+=09=09=09here->e_value_offs =3D 0;
 =09=09}
 =09=09if (value =3D=3D NULL) {
 =09=09=09/* Remove the old name. */
--=20
2.20.1