Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
From:   Sasha Levin <Alexander.Levin@microsoft.com>
To:     "stable@vger.kernel.org" <stable@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
CC:     Jon Maloy <jon.maloy@ericsson.com>,
        "David S . Miller" <davem@davemloft.net>,
        Sasha Levin <Alexander.Levin@microsoft.com>
Subject: [PATCH AUTOSEL for 4.15 007/189] tipc: fix a potental access after
 delete in tipc_sk_join()
Thread-Topic: [PATCH AUTOSEL for 4.15 007/189] tipc: fix a potental access
 after delete in tipc_sk_join()
Thread-Index: AQHTz5gNP1h0ZcAL+Uqpvhp0zbF5og==
Date:   Mon, 9 Apr 2018 00:16:49 +0000
Message-ID: <20180409001637.162453-7-alexander.levin@microsoft.com>
References: <20180409001637.162453-1-alexander.levin@microsoft.com>
In-Reply-To: <20180409001637.162453-1-alexander.levin@microsoft.com>
Accept-Language: en-US
Content-Language: en-US
received-spf: None (protection.outlook.com: microsoft.com does not designate
 permitted sender hosts)
spamdiagnosticoutput: 1:99
spamdiagnosticmetadata: NSPM
Content-Type: text/plain; charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
X-MS-Exchange-CrossTenant-Network-Message-Id: 3f2a5a8c-d336-4faf-4e64-08d59daf300e
X-MS-Exchange-CrossTenant-originalarrivaltime: 09 Apr 2018 00:16:49.2156
 (UTC)
X-MS-Exchange-CrossTenant-fromentityheader: Hosted
X-MS-Exchange-CrossTenant-id: 72f988bf-86f1-41af-91ab-2d7cd011db47
X-MS-Exchange-Transport-CrossTenantHeadersStamped: DM5PR2101MB0968
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

From: Jon Maloy <jon.maloy@ericsson.com>

[ Upstream commit febafc8455fdbb0ba53d596075068a683b75f355 ]

In commit d12d2e12cec2 "tipc: send out join messages as soon as new
member is discovered") we added a call to the function tipc_group_join()
without considering the case that the preceding tipc_sk_publish() might
have failed, and the group item already deleted.

We fix this by returning from tipc_sk_join() directly after the
failed tipc_sk_publish.

Reported-by: syzbot+e3eeae78ea88b8d6d858@syzkaller.appspotmail.com
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
---
 net/tipc/socket.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/tipc/socket.c b/net/tipc/socket.c
index 3b4084480377..8efd2e42de30 100644
--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -2759,6 +2759,7 @@ static int tipc_sk_join(struct tipc_sock *tsk, struct=
 tipc_group_req *mreq)
 	if (rc) {
 		tipc_group_delete(net, grp);
 		tsk->group =3D NULL;
+		return rc;
 	}
=20
 	/* Eliminate any risk that a broadcast overtakes the sent JOIN */
--=20
2.15.1