net: delete stale packet_mclist entries
When an interface is deleted from a net namespace the ifindex in the
corresponding entries in PF_PACKET sockets' mclists becomes stale.
This can create inconsistencies if later an interface with the same ifindex
is moved from a different namespace (not that unlikely since ifindexes are
per-namespace).
In particular we saw problems with dev->promiscuity, resulting
in "promiscuity touches roof, set promiscuity failed. promiscuity
feature of device might be broken" warnings and EOVERFLOW failures of
setsockopt(PACKET_ADD_MEMBERSHIP).
This patch deletes the mclist entries for interfaces that are deleted.
Since this now causes setsockopt(PACKET_DROP_MEMBERSHIP) to fail with
EADDRNOTAVAIL if called after the interface is deleted, also make
packet_mc_drop not fail.
Signed-off-by: Francesco Ruggeri <fruggeri@arista.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 5bf1e96..f8db706 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -3123,11 +3123,18 @@
return 0;
}
-static void packet_dev_mclist(struct net_device *dev, struct packet_mclist *i, int what)
+static void packet_dev_mclist_delete(struct net_device *dev,
+ struct packet_mclist **mlp)
{
- for ( ; i; i = i->next) {
- if (i->ifindex == dev->ifindex)
- packet_dev_mc(dev, i, what);
+ struct packet_mclist *ml;
+
+ while ((ml = *mlp) != NULL) {
+ if (ml->ifindex == dev->ifindex) {
+ packet_dev_mc(dev, ml, -1);
+ *mlp = ml->next;
+ kfree(ml);
+ } else
+ mlp = &ml->next;
}
}
@@ -3204,12 +3211,11 @@
packet_dev_mc(dev, ml, -1);
kfree(ml);
}
- rtnl_unlock();
- return 0;
+ break;
}
}
rtnl_unlock();
- return -EADDRNOTAVAIL;
+ return 0;
}
static void packet_flush_mclist(struct sock *sk)
@@ -3559,7 +3565,7 @@
switch (msg) {
case NETDEV_UNREGISTER:
if (po->mclist)
- packet_dev_mclist(dev, po->mclist, -1);
+ packet_dev_mclist_delete(dev, &po->mclist);
/* fallthrough */
case NETDEV_DOWN: