Re: [PATCHv2 net] bonding: fix ICMPv6 header handling when receiving IPv6 messages

Jonathan Toppins
2022-11-08T13:51:27Z

On 11/8/22 02:00, Hangbin Liu wrote:
> Currently, we get icmp6hdr via function icmp6_hdr(), which needs the skb
> transport header to be set first. But there is no rule to ask driver set
> transport header before netif_receive_skb() and bond_handle_frame(). So
> we will not able to get correct icmp6hdr on some drivers.
>
> Fix this by checking the skb length manually and getting icmp6 header based
> on the IPv6 header offset.
>
> Reported-by: Liang Li <liali@redhat.com>
> Fixes: 4e24be018eb9 ("bonding: add new parameter ns_targets")
> Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
> ---
> v2: use skb_header_pointer() to get icmp6hdr as Jay suggested.
> ---
> drivers/net/bonding/bond_main.c | 8 ++++++--
> 1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
> index e84c49bf4d0c..4599cf340201 100644
> --- a/drivers/net/bonding/bond_main.c
> +++ b/drivers/net/bonding/bond_main.c
> @@ -3231,12 +3231,16 @@ static int bond_na_rcv(const struct sk_buff *skb, struct bonding *bond,
> struct slave *slave)
> {
> struct slave *curr_active_slave, *curr_arp_slave;
> - struct icmp6hdr *hdr = icmp6_hdr(skb);
> + const struct icmp6hdr *hdr, _hdr;
> struct in6_addr *saddr, *daddr;
>
> if (skb->pkt_type == PACKET_OTHERHOST ||
> skb->pkt_type == PACKET_LOOPBACK ||
> - hdr->icmp6_type != NDISC_NEIGHBOUR_ADVERTISEMENT)
> + ipv6_hdr(skb)->nexthdr != NEXTHDR_ICMP)
> + goto out;
> +
> + hdr = skb_header_pointer(skb, sizeof(struct ipv6hdr), sizeof(_hdr), &_hdr);
> + if (!hdr || hdr->icmp6_type != NDISC_NEIGHBOUR_ADVERTISEMENT)
> goto out;
>
> saddr = &ipv6_hdr(skb)->saddr;

Acked-by: Jonathan Toppins <jtoppins@redhat.com>