Commit 5fc6266a authored by Linus Lüssing's avatar Linus Lüssing Committed by David S. Miller

bridge: mcast: Fix MLD2 Report IPv6 payload length check

Commit e57f6185 ("net: bridge: mcast: fix stale nsrcs pointer in
igmp3/mld2 report handling") introduced a bug in the IPv6 header payload
length check which would potentially lead to rejecting a valid MLD2 Report:

The check needs to take into account the 2 bytes for the "Number of
Sources" field in the "Multicast Address Record" before reading it.
And not the size of a pointer to this field.

Fixes: e57f6185 ("net: bridge: mcast: fix stale nsrcs pointer in igmp3/mld2 report handling")
Acked-by: default avatarNikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: default avatarLinus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 394de110
...@@ -1007,7 +1007,7 @@ static int br_ip6_multicast_mld2_report(struct net_bridge *br, ...@@ -1007,7 +1007,7 @@ static int br_ip6_multicast_mld2_report(struct net_bridge *br,
nsrcs_offset = len + offsetof(struct mld2_grec, grec_nsrcs); nsrcs_offset = len + offsetof(struct mld2_grec, grec_nsrcs);
if (skb_transport_offset(skb) + ipv6_transport_len(skb) < if (skb_transport_offset(skb) + ipv6_transport_len(skb) <
nsrcs_offset + sizeof(_nsrcs)) nsrcs_offset + sizeof(__nsrcs))
return -EINVAL; return -EINVAL;
_nsrcs = skb_header_pointer(skb, nsrcs_offset, _nsrcs = skb_header_pointer(skb, nsrcs_offset,
......
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