On Thu, Oct 19, 2017 at 10:21:08AM +0200, Michal Kubecek wrote:
> Commit 530903dd9003 ("ip: fix igmp parsing when iface is long") uses
> variable len to keep trailing colon from interface name comparison. This
> variable is local to loop body but we set it in one pass and use it in
> following one(s) so that we are actually using (pseudo)random length for
> comparison. This became apparent since commit b48a1161f5f9 ("ipmaddr: Avoid
> accessing uninitialized data") always initializes len to zero so that the
> name comparison is always true. As a result, "ip maddr show dev eth0" shows
> IPv4 multicast addresses for all interfaces.
>
> Instead of keeping the length, let's simply replace the trailing colon with
> a null byte. The bonus is that we get correct interface name in ma.name.
>
> Fixes: 530903dd9003 ("ip: fix igmp parsing when iface is long")
> Signed-off-by: Michal Kubecek <mkube...@suse.cz>
Acked-by: Phil Sutter <p...@nwl.cc>
