This is a note to let you know that I've just added the patch titled
sctp: read sk->sk_bound_dev_if once in sctp_rcv()
to the 5.18-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
sctp-read-sk-sk_bound_dev_if-once-in-sctp_rcv.patch
and it can be found in the queue-5.18 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit b1e4983767fa055bb4dc9a048b51b4687ee65386
Author: Eric Dumazet <edumazet@xxxxxxxxxx>
Date: Fri May 13 11:55:42 2022 -0700
sctp: read sk->sk_bound_dev_if once in sctp_rcv()
[ Upstream commit a20ea298071f46effa3aaf965bf9bb34c901db3f ]
sctp_rcv() reads sk->sk_bound_dev_if twice while the socket
is not locked. Another cpu could change this field under us.
Fixes: 0fd9a65a76e8 ("[SCTP] Support SO_BINDTODEVICE socket option on incoming packets.")
Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Cc: Neil Horman <nhorman@xxxxxxxxxxxxx>
Cc: Vlad Yasevich <vyasevich@xxxxxxxxx>
Cc: Marcelo Ricardo Leitner <marcelo.leitner@xxxxxxxxx>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/net/sctp/input.c b/net/sctp/input.c
index 90e12bafdd48..4f43afa8678f 100644
--- a/net/sctp/input.c
+++ b/net/sctp/input.c
@@ -92,6 +92,7 @@ int sctp_rcv(struct sk_buff *skb)
struct sctp_chunk *chunk;
union sctp_addr src;
union sctp_addr dest;
+ int bound_dev_if;
int family;
struct sctp_af *af;
struct net *net = dev_net(skb->dev);
@@ -169,7 +170,8 @@ int sctp_rcv(struct sk_buff *skb)
* If a frame arrives on an interface and the receiving socket is
* bound to another interface, via SO_BINDTODEVICE, treat it as OOTB
*/
- if (sk->sk_bound_dev_if && (sk->sk_bound_dev_if != af->skb_iif(skb))) {
+ bound_dev_if = READ_ONCE(sk->sk_bound_dev_if);
+ if (bound_dev_if && (bound_dev_if != af->skb_iif(skb))) {
if (transport) {
sctp_transport_put(transport);
asoc = NULL;
