This is a note to let you know that I've just added the patch titled
sctp: add the missing sock_owned_by_user check in sctp_icmp_redirect
to the 4.9-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-add-the-missing-sock_owned_by_user-check-in-sctp_icmp_redirect.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Wed Nov 15 17:24:03 CET 2017
From: Xin Long <lucien.xin@xxxxxxxxx>
Date: Wed, 18 Oct 2017 21:37:49 +0800
Subject: sctp: add the missing sock_owned_by_user check in sctp_icmp_redirect
From: Xin Long <lucien.xin@xxxxxxxxx>
[ Upstream commit 1cc276cec9ec574d41cf47dfc0f51406b6f26ab4 ]
Now sctp processes icmp redirect packet in sctp_icmp_redirect where
it calls sctp_transport_dst_check in which tp->dst can be released.
The problem is before calling sctp_transport_dst_check, it doesn't
check sock_owned_by_user, which means tp->dst could be freed while
a process is accessing it with owning the socket.
An use-after-free issue could be triggered by this.
This patch is to fix it by checking sock_owned_by_user before calling
sctp_transport_dst_check in sctp_icmp_redirect, so that it would not
release tp->dst if users still hold sock lock.
Besides, the same issue fixed in commit 45caeaa5ac0b ("dccp/tcp: fix
routing redirect race") on sctp also needs this check.
Fixes: 55be7a9c6074 ("ipv4: Add redirect support to all protocol icmp error handlers")
Reported-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Signed-off-by: Xin Long <lucien.xin@xxxxxxxxx>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@xxxxxxxxx>
Acked-by: Neil Horman <nhorman@xxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/sctp/input.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/net/sctp/input.c
+++ b/net/sctp/input.c
@@ -421,7 +421,7 @@ void sctp_icmp_redirect(struct sock *sk,
{
struct dst_entry *dst;
- if (!t)
+ if (sock_owned_by_user(sk) || !t)
return;
dst = sctp_transport_dst_check(t);
if (dst)
Patches currently in stable-queue which might be from lucien.xin@xxxxxxxxx are
queue-4.9/sctp-reset-owner-sk-for-data-chunks-on-out-queues-when-migrating-a-sock.patch
queue-4.9/ipip-only-increase-err_count-for-some-certain-type-icmp-in-ipip_err.patch
queue-4.9/sctp-full-support-for-ipv6-ip_nonlocal_bind-ip_freebind.patch
queue-4.9/sctp-add-the-missing-sock_owned_by_user-check-in-sctp_icmp_redirect.patch
queue-4.9/ip6_gre-only-increase-err_count-for-some-certain-type-icmpv6-in-ip6gre_err.patch
queue-4.9/ip6_gre-update-dst-pmtu-if-dev-mtu-has-been-updated-by-toobig-in-__gre6_xmit.patch