linux-kernel - [PATCH 4.14 11/29] caif_virtio: fix race between virtio_device_ready() and ndo

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: <20220705115606.676585095@linuxfoundation.org>
Date:   Tue,  5 Jul 2022 13:57:59 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Jason Wang <jasowang@...hat.com>,
        "Michael S. Tsirkin" <mst@...hat.com>
Subject: [PATCH 4.14 11/29] caif_virtio: fix race between virtio_device_ready() and ndo_open()

From: Jason Wang <jasowang@...hat.com>

commit 11a37eb66812ce6a06b79223ad530eb0e1d7294d upstream.

We currently depend on probe() calling virtio_device_ready() -
which happens after netdev
registration. Since ndo_open() can be called immediately
after register_netdev, this means there exists a race between
ndo_open() and virtio_device_ready(): the driver may start to use the
device (e.g. TX) before DRIVER_OK which violates the spec.

Fix this by switching to use register_netdevice() and protect the
virtio_device_ready() with rtnl_lock() to make sure ndo_open() can
only be called after virtio_device_ready().

Fixes: 0d2e1a2926b18 ("caif_virtio: Introduce caif over virtio")
Signed-off-by: Jason Wang <jasowang@...hat.com>
Message-Id: <20220620051115.3142-3-jasowang@...hat.com>
Signed-off-by: Michael S. Tsirkin <mst@...hat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
 drivers/net/caif/caif_virtio.c |   10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

--- a/drivers/net/caif/caif_virtio.c
+++ b/drivers/net/caif/caif_virtio.c
@@ -727,13 +727,21 @@ static int cfv_probe(struct virtio_devic
 	/* Carrier is off until netdevice is opened */
 	netif_carrier_off(netdev);
 
+	/* serialize netdev register + virtio_device_ready() with ndo_open() */
+	rtnl_lock();
+
 	/* register Netdev */
-	err = register_netdev(netdev);
+	err = register_netdevice(netdev);
 	if (err) {
+		rtnl_unlock();
 		dev_err(&vdev->dev, "Unable to register netdev (%d)\n", err);
 		goto err;
 	}
 
+	virtio_device_ready(vdev);
+
+	rtnl_unlock();
+
 	debugfs_init(cfv);
 
 	return 0;