kernel: fix corrupted ethernet header on bridge multicast-to-unicast

Fixes: 45a8e962a591 ("kernel: fix crash with multicast-to-unicast and fraglist GRO")
Signed-off-by: Felix Fietkau <[email protected]>

target/linux/generic/pending-6.1/684-net-bridge-fix-corrupted-ethernet-header-on-multicas.patch

@@ -0,0 +1,42 @@
+From: Felix Fietkau <[email protected]>
+Date: Sun, 5 May 2024 20:36:56 +0200
+Subject: [PATCH] net: bridge: fix corrupted ethernet header on
+ multicast-to-unicast
+
+The change from skb_copy to pskb_copy unfortunately changed the data
+copying to omit the ethernet header, since it was pulled before reaching
+this point. Fix this by calling __skb_push/pull around pskb_copy.
+
+Fixes: 59c878cbcdd8 ("net: bridge: fix multicast-to-unicast with fraglist GSO")
+Signed-off-by: Felix Fietkau <[email protected]>
+---
+
+--- a/net/bridge/br_forward.c
++++ b/net/bridge/br_forward.c
+@@ -253,6 +253,7 @@ static void maybe_deliver_addr(struct ne
+ {
+ 	struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev;
+ 	const unsigned char *src = eth_hdr(skb)->h_source;
++	struct sk_buff *nskb;
+ 
+ 	if (!should_deliver(p, skb))
+ 		return;
+@@ -261,12 +262,16 @@ static void maybe_deliver_addr(struct ne
+ 	if (skb->dev == p->dev && ether_addr_equal(src, addr))
+ 		return;
+ 
+-	skb = pskb_copy(skb, GFP_ATOMIC);
+-	if (!skb) {
++	__skb_push(skb, ETH_HLEN);
++	nskb = pskb_copy(skb, GFP_ATOMIC);
++	__skb_pull(skb, ETH_HLEN);
++	if (!nskb) {
+ 		DEV_STATS_INC(dev, tx_dropped);
+ 		return;
+ 	}
+ 
++	skb = nskb;
++	__skb_pull(skb, ETH_HLEN);
+ 	if (!is_broadcast_ether_addr(addr))
+ 		memcpy(eth_hdr(skb)->h_dest, addr, ETH_ALEN);
+ 

target/linux/generic/pending-6.6/684-net-bridge-fix-corrupted-ethernet-header-on-multicas.patch

@@ -0,0 +1,42 @@
+From: Felix Fietkau <[email protected]>
+Date: Sun, 5 May 2024 20:36:56 +0200
+Subject: [PATCH] net: bridge: fix corrupted ethernet header on
+ multicast-to-unicast
+
+The change from skb_copy to pskb_copy unfortunately changed the data
+copying to omit the ethernet header, since it was pulled before reaching
+this point. Fix this by calling __skb_push/pull around pskb_copy.
+
+Fixes: 59c878cbcdd8 ("net: bridge: fix multicast-to-unicast with fraglist GSO")
+Signed-off-by: Felix Fietkau <[email protected]>
+---
+
+--- a/net/bridge/br_forward.c
++++ b/net/bridge/br_forward.c
+@@ -258,6 +258,7 @@ static void maybe_deliver_addr(struct ne
+ {
+ 	struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev;
+ 	const unsigned char *src = eth_hdr(skb)->h_source;
++	struct sk_buff *nskb;
+ 
+ 	if (!should_deliver(p, skb))
+ 		return;
+@@ -266,12 +267,16 @@ static void maybe_deliver_addr(struct ne
+ 	if (skb->dev == p->dev && ether_addr_equal(src, addr))
+ 		return;
+ 
+-	skb = pskb_copy(skb, GFP_ATOMIC);
+-	if (!skb) {
++	__skb_push(skb, ETH_HLEN);
++	nskb = pskb_copy(skb, GFP_ATOMIC);
++	__skb_pull(skb, ETH_HLEN);
++	if (!nskb) {
+ 		DEV_STATS_INC(dev, tx_dropped);
+ 		return;
+ 	}
+ 
++	skb = nskb;
++	__skb_pull(skb, ETH_HLEN);
+ 	if (!is_broadcast_ether_addr(addr))
+ 		memcpy(eth_hdr(skb)->h_dest, addr, ETH_ALEN);
+