The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 23e7b1bfed61e301853b5e35472820d919498278 Mon Sep 17 00:00:00 2001
From: Guillaume Nault <gnault@xxxxxxxxxx>
Date: Mon, 10 Jan 2022 14:43:06 +0100
Subject: [PATCH] xfrm: Don't accidentally set RTO_ONLINK in decode_session4()
Similar to commit 94e2238969e8 ("xfrm4: strip ECN bits from tos field"),
clear the ECN bits from iph->tos when setting ->flowi4_tos.
This ensures that the last bit of ->flowi4_tos is cleared, so
ip_route_output_key_hash() isn't going to restrict the scope of the
route lookup.
Use ~INET_ECN_MASK instead of IPTOS_RT_MASK, because we have no reason
to clear the high order bits.
Found by code inspection, compile tested only.
Fixes: 4da3089f2b58 ("[IPSEC]: Use TOS when doing tunnel lookups")
Signed-off-by: Guillaume Nault <gnault@xxxxxxxxxx>
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index dccb8f3318ef..04d1ce9b510f 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -31,6 +31,7 @@
#include <linux/if_tunnel.h>
#include <net/dst.h>
#include <net/flow.h>
+#include <net/inet_ecn.h>
#include <net/xfrm.h>
#include <net/ip.h>
#include <net/gre.h>
@@ -3295,7 +3296,7 @@ decode_session4(struct sk_buff *skb, struct flowi *fl, bool reverse)
fl4->flowi4_proto = iph->protocol;
fl4->daddr = reverse ? iph->saddr : iph->daddr;
fl4->saddr = reverse ? iph->daddr : iph->saddr;
- fl4->flowi4_tos = iph->tos;
+ fl4->flowi4_tos = iph->tos & ~INET_ECN_MASK;
if (!ip_is_fragment(iph)) {
switch (iph->protocol) {
