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Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni Cc: bridge@lists.linux.dev, linux-kernel@vger.kernel.org References: <20240505184239.15002-1-nbd@nbd.name> Content-Language: en-US From: Nikolay Aleksandrov In-Reply-To: <20240505184239.15002-1-nbd@nbd.name> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 05/05/2024 21:42, Felix Fietkau wrote: > 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 > --- > net/bridge/br_forward.c | 9 +++++++-- > 1 file changed, 7 insertions(+), 2 deletions(-) > > diff --git a/net/bridge/br_forward.c b/net/bridge/br_forward.c > index d7c35f55bd69..d97064d460dc 100644 > --- a/net/bridge/br_forward.c > +++ b/net/bridge/br_forward.c > @@ -258,6 +258,7 @@ static void maybe_deliver_addr(struct net_bridge_port *p, struct sk_buff *skb, > { > 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 net_bridge_port *p, struct sk_buff *skb, > 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); > This dance is getting ugly, but better to have it correct. It'd be nice if you could add a selftest that exercises it. Acked-by: Nikolay Aleksandrov