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authorstephen hemminger <stephen@networkplumber.org>2017-01-11 09:16:32 -0800
committerDavid S. Miller <davem@davemloft.net>2017-01-11 16:13:53 -0500
commit0719e72ccb801829a3d735d187ca8417f0930459 (patch)
treea4f718fefcb15433fa59f6d4add44ae220edb806 /drivers/net/hyperv
parent4ecb1d83f6abe8d49163427f4d431ebe98f8bd5f (diff)
netvsc: add rcu_read locking to netvsc callback
The receive callback (in tasklet context) is using RCU to get reference to associated VF network device but this is not safe. RCU read lock needs to be held. Found by running with full lockdep debugging enabled. Fixes: f207c10d9823 ("hv_netvsc: use RCU to protect vf_netdev") Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/hyperv')
-rw-r--r--drivers/net/hyperv/netvsc_drv.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index c9414c054852..fcab8019dda0 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -659,6 +659,7 @@ int netvsc_recv_callback(struct hv_device *device_obj,
* policy filters on the host). Deliver these via the VF
* interface in the guest.
*/
+ rcu_read_lock();
vf_netdev = rcu_dereference(net_device_ctx->vf_netdev);
if (vf_netdev && (vf_netdev->flags & IFF_UP))
net = vf_netdev;
@@ -667,6 +668,7 @@ int netvsc_recv_callback(struct hv_device *device_obj,
skb = netvsc_alloc_recv_skb(net, packet, csum_info, *data, vlan_tci);
if (unlikely(!skb)) {
++net->stats.rx_dropped;
+ rcu_read_unlock();
return NVSP_STAT_FAIL;
}
@@ -696,6 +698,7 @@ int netvsc_recv_callback(struct hv_device *device_obj,
* TODO - use NAPI?
*/
netif_rx(skb);
+ rcu_read_unlock();
return 0;
}