6.17-stable review patch. If anyone has any objections, please let me know.
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From: Jianbo Liu jianbol@nvidia.com
[ Upstream commit 082ef944e55da8a9a8df92e3842ca82a626d359a ]
In the output path, xfrm_dev_offload_ok and xfrm_get_inner_ipproto need to determine the protocol family of the inner packet (skb) before it gets encapsulated.
In xfrm_dev_offload_ok, the code checked x->inner_mode.family. This is unreliable because, for states handling both IPv4 and IPv6, the relevant inner family could be either x->inner_mode.family or x->inner_mode_iaf.family. Checking only the former can lead to a mismatch with the actual packet being processed.
In xfrm_get_inner_ipproto, the code checked x->outer_mode.family. This is also incorrect for tunnel mode, as the inner packet's family can be different from the outer header's family.
At both of these call sites, the skb variable holds the original inner packet. The most direct and reliable source of truth for its protocol family is its destination entry. This patch fixes the issue by using skb_dst(skb)->ops->family to ensure protocol-specific headers are only accessed for the correct packet type.
Fixes: 91d8a53db219 ("xfrm: fix offloading of cross-family tunnels") Fixes: 45a98ef4922d ("net/xfrm: IPsec tunnel mode fix inner_ipproto setting in sec_path") Signed-off-by: Jianbo Liu jianbol@nvidia.com Reviewed-by: Cosmin Ratiu cratiu@nvidia.com Reviewed-by: Zhu Yanjun yanjun.zhu@linux.dev Reviewed-by: Sabrina Dubroca sd@queasysnail.net Signed-off-by: Steffen Klassert steffen.klassert@secunet.com Signed-off-by: Sasha Levin sashal@kernel.org --- net/xfrm/xfrm_device.c | 2 +- net/xfrm/xfrm_output.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/net/xfrm/xfrm_device.c b/net/xfrm/xfrm_device.c index 44b9de6e4e778..52ae0e034d29e 100644 --- a/net/xfrm/xfrm_device.c +++ b/net/xfrm/xfrm_device.c @@ -438,7 +438,7 @@ bool xfrm_dev_offload_ok(struct sk_buff *skb, struct xfrm_state *x)
check_tunnel_size = x->xso.type == XFRM_DEV_OFFLOAD_PACKET && x->props.mode == XFRM_MODE_TUNNEL; - switch (x->inner_mode.family) { + switch (skb_dst(skb)->ops->family) { case AF_INET: /* Check for IPv4 options */ if (ip_hdr(skb)->ihl != 5) diff --git a/net/xfrm/xfrm_output.c b/net/xfrm/xfrm_output.c index 9077730ff7d0e..a98b5bf55ac31 100644 --- a/net/xfrm/xfrm_output.c +++ b/net/xfrm/xfrm_output.c @@ -698,7 +698,7 @@ static void xfrm_get_inner_ipproto(struct sk_buff *skb, struct xfrm_state *x) return;
if (x->outer_mode.encap == XFRM_MODE_TUNNEL) { - switch (x->outer_mode.family) { + switch (skb_dst(skb)->ops->family) { case AF_INET: xo->inner_ipproto = ip_hdr(skb)->protocol; break;