This is a note to let you know that I've just added the patch titled
tuntap: forbid changing mq flag for persistent device
to the 3.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
tuntap-forbid-changing-mq-flag-for-persistent-device.patch
and it can be found in the queue-3.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 2c842b06d95ab8388d58d21b8d6ef60545415cd5 Mon Sep 17 00:00:00 2001
From: Jason Wang <jasowang@xxxxxxxxxx>
Date: Tue, 28 May 2013 18:32:11 +0000
Subject: tuntap: forbid changing mq flag for persistent device
From: Jason Wang <jasowang@xxxxxxxxxx>
[ Upstream commit 8e6d91ae0917bf934ed86411148f79d904728d51 ]
We currently allow changing the mq flag (IFF_MULTI_QUEUE) for a persistent
device. This will result a mismatch between the number the queues in netdev and
tuntap. This is because we only allocate a 1q netdevice when IFF_MULTI_QUEUE was
not specified, so when we set the IFF_MULTI_QUEUE and try to attach more queues
later, netif_set_real_num_tx_queues() may fail which result a single queue
netdevice with multiple sockets attached.
Solve this by disallowing changing the mq flag for persistent device.
Bug was introduced by commit edfb6a148ce62e5e19354a1dcd9a34e00815c2a1
(tuntap: reduce memory using of queues).
Reported-by: Sriram Narasimhan <sriram.narasimhan@xxxxxx>
Cc: Michael S. Tsirkin <mst@xxxxxxxxxx>
Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/tun.c | 4 ++++
1 file changed, 4 insertions(+)
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -1585,6 +1585,10 @@ static int tun_set_iff(struct net *net,
else
return -EINVAL;
+ if (!!(ifr->ifr_flags & IFF_MULTI_QUEUE) !=
+ !!(tun->flags & TUN_TAP_MQ))
+ return -EINVAL;
+
if (tun_not_capable(tun))
return -EPERM;
err = security_tun_dev_open(tun->security);
Patches currently in stable-queue which might be from jasowang@xxxxxxxxxx are
queue-3.9/tuntap-forbid-changing-mq-flag-for-persistent-device.patch
queue-3.9/packet-set-transport-header-before-doing-xmit.patch
queue-3.9/netback-set-transport-header-before-passing-it-to-kernel.patch
queue-3.9/net_sched-better-precise-estimation-on-packet-length-for-untrusted-packets.patch
queue-3.9/tuntap-set-sock_zerocopy-flag-during-open.patch
queue-3.9/tuntap-set-transport-header-before-passing-it-to-kernel.patch
queue-3.9/tuntap-correct-the-return-value-in-tun_set_iff.patch
queue-3.9/macvtap-set-transport-header-before-passing-skb-to-lower-device.patch
queue-3.9/vhost_net-clear-msg.control-for-non-zerocopy-case-during-tx.patch
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