From 9b64e93e83c2145a750e780198b41d612e3dfa5d Mon Sep 17 00:00:00 2001 From: Kuniyuki Iwashima Date: Tue, 18 Jul 2023 10:41:49 -0700 Subject: llc: Check netns in llc_dgram_match(). We will remove this restriction in llc_rcv() soon, which means that the protocol handler must be aware of netns. if (!net_eq(dev_net(dev), &init_net)) goto drop; llc_rcv() fetches llc_type_handlers[llc_pdu_type(skb) - 1] and calls it if not NULL. If the PDU type is LLC_DEST_SAP, llc_sap_handler() is called to pass skb to corresponding sockets. Then, we must look up a proper socket in the same netns with skb->dev. If the destination is a multicast address, llc_sap_handler() calls llc_sap_mcast(). It calculates a hash based on DSAP and skb->dev->ifindex, iterates on a socket list, and calls llc_mcast_match() to check if the socket is the correct destination. Then, llc_mcast_match() checks if skb->dev matches with llc_sk(sk)->dev. So, we need not check netns here. OTOH, if the destination is a unicast address, llc_sap_handler() calls llc_lookup_dgram() to look up a socket, but it does not check the netns. Therefore, we need to add netns check in llc_lookup_dgram(). Signed-off-by: Kuniyuki Iwashima Signed-off-by: Paolo Abeni --- net/llc/llc_sap.c | 18 +++++++++++------- 1 file changed, 11 insertions(+), 7 deletions(-) diff --git a/net/llc/llc_sap.c b/net/llc/llc_sap.c index 6805ce43a055..116c0e479183 100644 --- a/net/llc/llc_sap.c +++ b/net/llc/llc_sap.c @@ -294,25 +294,29 @@ static void llc_sap_rcv(struct llc_sap *sap, struct sk_buff *skb, static inline bool llc_dgram_match(const struct llc_sap *sap, const struct llc_addr *laddr, - const struct sock *sk) + const struct sock *sk, + const struct net *net) { struct llc_sock *llc = llc_sk(sk); return sk->sk_type == SOCK_DGRAM && - llc->laddr.lsap == laddr->lsap && - ether_addr_equal(llc->laddr.mac, laddr->mac); + net_eq(sock_net(sk), net) && + llc->laddr.lsap == laddr->lsap && + ether_addr_equal(llc->laddr.mac, laddr->mac); } /** * llc_lookup_dgram - Finds dgram socket for the local sap/mac * @sap: SAP * @laddr: address of local LLC (MAC + SAP) + * @net: netns to look up a socket in * * Search socket list of the SAP and finds connection using the local * mac, and local sap. Returns pointer for socket found, %NULL otherwise. */ static struct sock *llc_lookup_dgram(struct llc_sap *sap, - const struct llc_addr *laddr) + const struct llc_addr *laddr, + const struct net *net) { struct sock *rc; struct hlist_nulls_node *node; @@ -322,12 +326,12 @@ static struct sock *llc_lookup_dgram(struct llc_sap *sap, rcu_read_lock_bh(); again: sk_nulls_for_each_rcu(rc, node, laddr_hb) { - if (llc_dgram_match(sap, laddr, rc)) { + if (llc_dgram_match(sap, laddr, rc, net)) { /* Extra checks required by SLAB_TYPESAFE_BY_RCU */ if (unlikely(!refcount_inc_not_zero(&rc->sk_refcnt))) goto again; if (unlikely(llc_sk(rc)->sap != sap || - !llc_dgram_match(sap, laddr, rc))) { + !llc_dgram_match(sap, laddr, rc, net))) { sock_put(rc); continue; } @@ -429,7 +433,7 @@ void llc_sap_handler(struct llc_sap *sap, struct sk_buff *skb) llc_sap_mcast(sap, &laddr, skb); kfree_skb(skb); } else { - struct sock *sk = llc_lookup_dgram(sap, &laddr); + struct sock *sk = llc_lookup_dgram(sap, &laddr, dev_net(skb->dev)); if (sk) { llc_sap_rcv(sap, skb, sk); sock_put(sk); -- cgit v1.2.3