5.15-stable review patch. If anyone has any objections, please let me know.
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From: Jeremy Kerr jk@codeconstruct.com.au
[ Upstream commit 1f6c77ac9e6ecef152fd5df94c4b3c346adb197a ]
We may need to receive packets addressed to the null EID (==0), but addressed to us at the physical layer.
This change adds a lookup for local routes when we see a packet addressed to EID 0, and a local phys address.
Signed-off-by: Jeremy Kerr jk@codeconstruct.com.au Signed-off-by: David S. Miller davem@davemloft.net Stable-dep-of: 5093bbfc10ab ("mctp: perform route lookups under a RCU read-side lock") Signed-off-by: Sasha Levin sashal@kernel.org --- net/mctp/route.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+)
diff --git a/net/mctp/route.c b/net/mctp/route.c index 89e67399249b4..859f57fd3871f 100644 --- a/net/mctp/route.c +++ b/net/mctp/route.c @@ -480,6 +480,10 @@ static int mctp_alloc_local_tag(struct mctp_sock *msk, int rc = -EAGAIN; u8 tagbits;
+ /* for NULL destination EIDs, we may get a response from any peer */ + if (daddr == MCTP_ADDR_NULL) + daddr = MCTP_ADDR_ANY; + /* be optimistic, alloc now */ key = mctp_key_alloc(msk, saddr, daddr, 0, GFP_KERNEL); if (!key) @@ -558,6 +562,20 @@ struct mctp_route *mctp_route_lookup(struct net *net, unsigned int dnet, return rt; }
+static struct mctp_route *mctp_route_lookup_null(struct net *net, + struct net_device *dev) +{ + struct mctp_route *rt; + + list_for_each_entry_rcu(rt, &net->mctp.routes, list) { + if (rt->dev->dev == dev && rt->type == RTN_LOCAL && + refcount_inc_not_zero(&rt->refs)) + return rt; + } + + return NULL; +} + /* sends a skb to rt and releases the route. */ int mctp_do_route(struct mctp_route *rt, struct sk_buff *skb) { @@ -853,6 +871,11 @@ static int mctp_pkttype_receive(struct sk_buff *skb, struct net_device *dev, rcu_read_unlock();
rt = mctp_route_lookup(net, cb->net, mh->dest); + + /* NULL EID, but addressed to our physical address */ + if (!rt && mh->dest == MCTP_ADDR_NULL && skb->pkt_type == PACKET_HOST) + rt = mctp_route_lookup_null(net, dev); + if (!rt) goto err_drop;