This is a note to let you know that I've just added the patch titled
xfrm: fix "disable_policy" on ipv4 early demux
to the 5.15-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:
xfrm-fix-disable_policy-on-ipv4-early-demux.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 3c1f8ce26a7fd2951da47105171ba4d224fb8dc8
Author: Eyal Birger <eyal.birger@xxxxxxxxx>
Date: Sun Oct 9 22:16:43 2022 +0300
xfrm: fix "disable_policy" on ipv4 early demux
[ Upstream commit 3a5913183aa1b14148c723bda030e6102ad73008 ]
The commit in the "Fixes" tag tried to avoid a case where policy check
is ignored due to dst caching in next hops.
However, when the traffic is locally consumed, the dst may be cached
in a local TCP or UDP socket as part of early demux. In this case the
"disable_policy" flag is not checked as ip_route_input_noref() was only
called before caching, and thus, packets after the initial packet in a
flow will be dropped if not matching policies.
Fix by checking the "disable_policy" flag also when a valid dst is
already available.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216557
Reported-by: Monil Patel <monil191989@xxxxxxxxx>
Fixes: e6175a2ed1f1 ("xfrm: fix "disable_policy" flag use when arriving from different devices")
Signed-off-by: Eyal Birger <eyal.birger@xxxxxxxxx>
----
v2: use dev instead of skb->dev
Signed-off-by: Steffen Klassert <steffen.klassert@xxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/net/ipv4/ip_input.c b/net/ipv4/ip_input.c
index 459d7e630cb0..124bf8fdf924 100644
--- a/net/ipv4/ip_input.c
+++ b/net/ipv4/ip_input.c
@@ -364,6 +364,11 @@ static int ip_rcv_finish_core(struct net *net, struct sock *sk,
iph->tos, dev);
if (unlikely(err))
goto drop_error;
+ } else {
+ struct in_device *in_dev = __in_dev_get_rcu(dev);
+
+ if (in_dev && IN_DEV_ORCONF(in_dev, NOPOLICY))
+ IPCB(skb)->flags |= IPSKB_NOPOLICY;
}
#ifdef CONFIG_IP_ROUTE_CLASSID
