From: Guillaume Nault <gnault@xxxxxxxxxx> commit 23e7b1bfed61e301853b5e35472820d919498278 upstream. 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> [sudip: manually backport to previous location] Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/ipv4/xfrm4_policy.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/net/ipv4/xfrm4_policy.c +++ b/net/ipv4/xfrm4_policy.c @@ -16,6 +16,7 @@ #include <net/xfrm.h> #include <net/ip.h> #include <net/l3mdev.h> +#include <net/inet_ecn.h> static struct xfrm_policy_afinfo xfrm4_policy_afinfo; @@ -123,7 +124,7 @@ _decode_session4(struct sk_buff *skb, st 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) { Patches currently in stable-queue which might be from gnault@xxxxxxxxxx are queue-4.9/xfrm-don-t-accidentally-set-rto_onlink-in-decode_session4.patch