Patch "xfrm: replay: Fix ESN wrap around for GSO" has been added to the 6.0-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    xfrm: replay: Fix ESN wrap around for GSO

to the 6.0-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-replay-fix-esn-wrap-around-for-gso.patch
and it can be found in the queue-6.0 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 077c9a443722578c9646cc69d8fcf22586195633
Author: Christian Langrock <christian.langrock@xxxxxxxxxxx>
Date:   Mon Oct 17 08:34:47 2022 +0200

    xfrm: replay: Fix ESN wrap around for GSO
    
    [ Upstream commit 4b549ccce941798703f159b227aa28c716aa78fa ]
    
    When using GSO it can happen that the wrong seq_hi is used for the last
    packets before the wrap around. This can lead to double usage of a
    sequence number. To avoid this, we should serialize this last GSO
    packet.
    
    Fixes: d7dbefc45cf5 ("xfrm: Add xfrm_replay_overflow functions for offloading")
    Co-developed-by: Steffen Klassert <steffen.klassert@xxxxxxxxxxx>
    Signed-off-by: Christian Langrock <christian.langrock@xxxxxxxxxxx>
    Signed-off-by: Steffen Klassert <steffen.klassert@xxxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/net/ipv4/esp4_offload.c b/net/ipv4/esp4_offload.c
index 170152772d33..3969fa805679 100644
--- a/net/ipv4/esp4_offload.c
+++ b/net/ipv4/esp4_offload.c
@@ -314,6 +314,9 @@ static int esp_xmit(struct xfrm_state *x, struct sk_buff *skb,  netdev_features_
 			xo->seq.low += skb_shinfo(skb)->gso_segs;
 	}
 
+	if (xo->seq.low < seq)
+		xo->seq.hi++;
+
 	esp.seqno = cpu_to_be64(seq + ((u64)xo->seq.hi << 32));
 
 	ip_hdr(skb)->tot_len = htons(skb->len);
diff --git a/net/ipv6/esp6_offload.c b/net/ipv6/esp6_offload.c
index 79d43548279c..242f4295940e 100644
--- a/net/ipv6/esp6_offload.c
+++ b/net/ipv6/esp6_offload.c
@@ -346,6 +346,9 @@ static int esp6_xmit(struct xfrm_state *x, struct sk_buff *skb,  netdev_features
 			xo->seq.low += skb_shinfo(skb)->gso_segs;
 	}
 
+	if (xo->seq.low < seq)
+		xo->seq.hi++;
+
 	esp.seqno = cpu_to_be64(xo->seq.low + ((u64)xo->seq.hi << 32));
 
 	len = skb->len - sizeof(struct ipv6hdr);
diff --git a/net/xfrm/xfrm_device.c b/net/xfrm/xfrm_device.c
index 637ca8838436..9af6bf1652e4 100644
--- a/net/xfrm/xfrm_device.c
+++ b/net/xfrm/xfrm_device.c
@@ -97,6 +97,18 @@ static void xfrm_outer_mode_prep(struct xfrm_state *x, struct sk_buff *skb)
 	}
 }
 
+static inline bool xmit_xfrm_check_overflow(struct sk_buff *skb)
+{
+	struct xfrm_offload *xo = xfrm_offload(skb);
+	__u32 seq = xo->seq.low;
+
+	seq += skb_shinfo(skb)->gso_segs;
+	if (unlikely(seq < xo->seq.low))
+		return true;
+
+	return false;
+}
+
 struct sk_buff *validate_xmit_xfrm(struct sk_buff *skb, netdev_features_t features, bool *again)
 {
 	int err;
@@ -134,7 +146,8 @@ struct sk_buff *validate_xmit_xfrm(struct sk_buff *skb, netdev_features_t featur
 		return skb;
 	}
 
-	if (skb_is_gso(skb) && unlikely(x->xso.dev != dev)) {
+	if (skb_is_gso(skb) && (unlikely(x->xso.dev != dev) ||
+				unlikely(xmit_xfrm_check_overflow(skb)))) {
 		struct sk_buff *segs;
 
 		/* Packet got rerouted, fixup features and segment it. */
diff --git a/net/xfrm/xfrm_replay.c b/net/xfrm/xfrm_replay.c
index 9277d81b344c..49dd788859d8 100644
--- a/net/xfrm/xfrm_replay.c
+++ b/net/xfrm/xfrm_replay.c
@@ -714,7 +714,7 @@ static int xfrm_replay_overflow_offload_esn(struct xfrm_state *x, struct sk_buff
 			oseq += skb_shinfo(skb)->gso_segs;
 		}
 
-		if (unlikely(oseq < replay_esn->oseq)) {
+		if (unlikely(xo->seq.low < replay_esn->oseq)) {
 			XFRM_SKB_CB(skb)->seq.output.hi = ++oseq_hi;
 			xo->seq.hi = oseq_hi;
 			replay_esn->oseq_hi = oseq_hi;