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

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

From: Eric Dumazet <[email protected]>

[ Upstream commit 3e3aac497513c669e1c62c71e1d552ea85c1d974 ]

egress_priority_map[] hash table updates are protected by rtnl,
and we never remove elements until device is dismantled.

We have to make sure that before inserting an new element in hash table,
all its fields are committed to memory or else another cpu could
find corrupt values and crash.

Signed-off-by: Eric Dumazet <[email protected]>
Cc: Patrick McHardy <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
 net/8021q/vlan_dev.c |    7 +++++++
 1 file changed, 7 insertions(+)

--- a/net/8021q/vlan_dev.c
+++ b/net/8021q/vlan_dev.c
@@ -70,6 +70,8 @@ vlan_dev_get_egress_qos_mask(struct net_
 {
        struct vlan_priority_tci_mapping *mp;
 
+       smp_rmb(); /* coupled with smp_wmb() in vlan_dev_set_egress_priority() 
*/
+
        mp = vlan_dev_info(dev)->egress_priority_map[(skb->priority & 0xF)];
        while (mp) {
                if (mp->priority == skb->priority) {
@@ -230,6 +232,11 @@ int vlan_dev_set_egress_priority(const s
        np->next = mp;
        np->priority = skb_prio;
        np->vlan_qos = vlan_qos;
+       /* Before inserting this element in hash table, make sure all its fields
+        * are committed to memory.
+        * coupled with smp_rmb() in vlan_dev_get_egress_qos_mask()
+        */
+       smp_wmb();
        vlan->egress_priority_map[skb_prio & 0xF] = np;
        if (vlan_qos)
                vlan->nr_egress_mappings++;


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to