linux-kernel - [PATCH 4.20 031/117] ceph: clear inode pointer when snap realm gets dropped by its inode

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20190129113209.188029321@linuxfoundation.org>
Date:   Tue, 29 Jan 2019 12:34:42 +0100
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, "Yan, Zheng" <zyan@...hat.com>,
        Luis Henriques <lhenriques@...e.com>,
        Ilya Dryomov <idryomov@...il.com>
Subject: [PATCH 4.20 031/117] ceph: clear inode pointer when snap realm gets dropped by its inode

4.20-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Yan, Zheng <zyan@...hat.com>

commit d95e674c01cfb5461e8b9fdeebf6d878c9b80b2f upstream.

snap realm and corresponding inode have pointers to each other.
The two pointer should get clear at the same time. Otherwise,
snap realm's pointer may reference freed inode.

Cc: stable@...r.kernel.org # 4.17+
Signed-off-by: "Yan, Zheng" <zyan@...hat.com>
Reviewed-by: Luis Henriques <lhenriques@...e.com>
Signed-off-by: Ilya Dryomov <idryomov@...il.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 fs/ceph/caps.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -1032,6 +1032,8 @@ static void drop_inode_snap_realm(struct
 	list_del_init(&ci->i_snap_realm_item);
 	ci->i_snap_realm_counter++;
 	ci->i_snap_realm = NULL;
+	if (realm->ino == ci->i_vino.ino)
+		realm->inode = NULL;
 	spin_unlock(&realm->inodes_with_caps_lock);
 	ceph_put_snap_realm(ceph_sb_to_client(ci->vfs_inode.i_sb)->mdsc,
 			    realm);