net: delete stale packet_mclist entries (82f17091) · Commits · 戴 / test

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>

net/packet/af_packet.c

+14 −8

Original line number	Diff line number	Diff line
		@@ -3123,11 +3123,18 @@ static int packet_dev_mc(struct net_device dev, struct packet_mclist i,
		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 @@ static int packet_mc_drop(struct sock sk, struct packet_mreq_max mreq)
		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 @@ static int packet_notifier(struct notifier_block *this,
		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:

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