bridge: Fix IPv6 multicast snooping by correcting offset in MLDv2 report
We actually want a pointer to the grec_nsrcr and not the following
field. Otherwise we can get very high values for *nsrcs as the first two
bytes of the IPv6 multicast address are being used instead, leading to
a failing pskb_may_pull() which results in MLDv2 reports not being
parsed.
Signed-off-by: Linus Lüssing <linus.luessing@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c
index 17708fc..d69beaf 100644
--- a/net/bridge/br_multicast.c
+++ b/net/bridge/br_multicast.c
@@ -1013,7 +1013,7 @@
nsrcs = skb_header_pointer(skb,
len + offsetof(struct mld2_grec,
- grec_mca),
+ grec_nsrcs),
sizeof(_nsrcs), &_nsrcs);
if (!nsrcs)
return -EINVAL;
