Fix for non-linear skb

src/patches/003-fix-for-non-linear-skb.patch

@@ -0,0 +1,51 @@
+diff --git receive.c receive.c
+index b3e0040..e42006d 100644
+--- receive.c
++++ receive.c
+@@ -54,10 +54,9 @@ static size_t validate_header_len(struct sk_buff *skb, struct wg_device *wg)
+ 	return 0;
+ }
+ 
+-void prepare_advanced_secured_message(struct sk_buff *skb, struct wg_device *wg)
++static void prepare_advanced_secured_message(struct sk_buff *skb, struct wg_device *wg)
+ {
+-	u32 assumed_type = SKB_TYPE_LE32(skb);
+-	u32 assumed_offset;
++	u32 assumed_type, assumed_offset;
+ 
+ 	if (wg->advanced_security_config.advanced_security) {
+ 		if (skb->len == MESSAGE_INITIATION_SIZE + wg->advanced_security_config.init_packet_junk_size) {
+@@ -72,6 +71,11 @@ void prepare_advanced_secured_message(struct sk_buff *skb, struct wg_device *wg)
+ 		if (unlikely(assumed_offset <= 0) || unlikely(!pskb_may_pull(skb, assumed_offset)))
+ 			return;
+ 
++		if (skb_is_nonlinear(skb) && unlikely(skb_linearize(skb))) {
++			net_dbg_skb_ratelimited("%s: non-linear sk_buff from %pISpfsc could not be linearized, dropping packet\n",
++			                        wg->dev->name, skb);
++			return;
++		}
+ 
+ 		skb_pull(skb, assumed_offset);
+ 
+diff --git send.c send.c
+index d65e58b..d6c27f1 100644
+--- send.c
++++ send.c
+@@ -20,7 +20,7 @@
+ #include <net/udp.h>
+ #include <net/sock.h>
+ 
+-u32 wg_get_random_u32_inclusive(u32 floor, u32 ceil)
++static u32 wg_get_random_u32_inclusive(u32 floor, u32 ceil)
+ {
+ 	u32 diff = ceil - floor + 1;
+ 	return floor + (get_random_u32() % diff);
+@@ -68,7 +60,7 @@ static void wg_packet_send_handshake_initiation(struct wg_peer *peer)
+ 		kfree(buffer);
+ 	}
+ 
+-	net_dbg_ratelimited("%s: Initiation magic header: %llu\n",
++	net_dbg_ratelimited("%s: Initiation magic header: %u\n",
+ 	                    peer->device->dev->name,
+ 						peer->advanced_security ? wg->advanced_security_config.init_packet_magic_header :
+ 						MESSAGE_HANDSHAKE_INITIATION);

src/receive.c

@@ -54,10 +54,9 @@ static size_t validate_header_len(struct sk_buff *skb, struct wg_device *wg)
 	return 0;
 }
 
-void prepare_advanced_secured_message(struct sk_buff *skb, struct wg_device *wg)
+static void prepare_advanced_secured_message(struct sk_buff *skb, struct wg_device *wg)
 {
-	u32 assumed_type = SKB_TYPE_LE32(skb);
-	u32 assumed_offset;
+	u32 assumed_type, assumed_offset;
 
 	if (wg->advanced_security_config.advanced_security) {
 		if (skb->len == MESSAGE_INITIATION_SIZE + wg->advanced_security_config.init_packet_junk_size) {
@@ -72,14 +71,14 @@ void prepare_advanced_secured_message(struct sk_buff *skb, struct wg_device *wg)
 		if (unlikely(assumed_offset <= 0) || unlikely(!pskb_may_pull(skb, assumed_offset)))
 			return;
 
-		net_dbg_skb_ratelimited("%s: Likely received handshake packet from %pISpfsc, assuming its type %l with offset %l (current type %l)\n",
-		                        wg->dev->name, skb, assumed_type, assumed_offset, SKB_TYPE_LE32(skb));
+		if (skb_is_nonlinear(skb) && unlikely(skb_linearize(skb))) {
+			net_dbg_skb_ratelimited("%s: non-linear sk_buff from %pISpfsc could not be linearized, dropping packet\n",
+			                        wg->dev->name, skb);
+			return;
+		}
 
 		skb_pull(skb, assumed_offset);
 
-		net_dbg_skb_ratelimited("%s: Packet from %pISpfsc real type after skb_pull %l\n",
-		                        wg->dev->name, skb, SKB_TYPE_LE32(skb));
-
 		if (SKB_TYPE_LE32(skb) != assumed_type) {
 			skb_push(skb, assumed_offset);
 		}

src/send.c

@@ -20,7 +20,7 @@
 #include <net/udp.h>
 #include <net/sock.h>
 
-u32 wg_get_random_u32_inclusive(u32 floor, u32 ceil)
+static u32 wg_get_random_u32_inclusive(u32 floor, u32 ceil)
 {
 	u32 diff = ceil - floor + 1;
 	return floor + (get_random_u32() % diff);
@@ -47,19 +47,11 @@ static void wg_packet_send_handshake_initiation(struct wg_peer *peer)
 		junk_packet_count = wg->advanced_security_config.junk_packet_count;
 		buffer = kzalloc(wg->advanced_security_config.junk_packet_max_size, GFP_KERNEL);
 
-		net_dbg_ratelimited("%s: Sending %llu junk packets to peer %llu (%pISpfsc)\n",
-		                    peer->device->dev->name, junk_packet_count, peer->internal_id,
-		                    &peer->endpoint.addr);
-
 		while (junk_packet_count-- > 0) {
 			junk_packet_size = (u16) wg_get_random_u32_inclusive(
 					wg->advanced_security_config.junk_packet_min_size,
 					wg->advanced_security_config.junk_packet_max_size);
 
-			net_dbg_ratelimited("%s: Sending %llu size junk packet to peer %llu (%pISpfsc)\n",
-			                    peer->device->dev->name, junk_packet_size, peer->internal_id,
-			                    &peer->endpoint.addr);
-
 			get_random_bytes(buffer, junk_packet_size);
 			get_random_bytes(&ds, 1);
 			wg_socket_send_buffer_to_peer(peer, buffer, junk_packet_size, ds);
@@ -68,7 +60,7 @@ static void wg_packet_send_handshake_initiation(struct wg_peer *peer)
 		kfree(buffer);
 	}
 
-	net_dbg_ratelimited("%s: Initiation magic header: %llu\n",
+	net_dbg_ratelimited("%s: Initiation magic header: %u\n",
 	                    peer->device->dev->name,
 						peer->advanced_security ? wg->advanced_security_config.init_packet_magic_header :
 						MESSAGE_HANDSHAKE_INITIATION);
@@ -82,9 +74,6 @@ static void wg_packet_send_handshake_initiation(struct wg_peer *peer)
 			     ktime_get_coarse_boottime_ns());
 
 		if (wg->advanced_security_config.advanced_security && peer->advanced_security) {
-			net_dbg_ratelimited("%s: Initiation junked packet: %llu\n",
-			                    peer->device->dev->name, wg->advanced_security_config.init_packet_junk_size);
-
 			wg_socket_send_junked_buffer_to_peer(peer, &packet, sizeof(packet),
 			                              HANDSHAKE_DSCP, wg->advanced_security_config.init_packet_junk_size);
 		} else {