Messages in this thread | | | Date | Mon, 18 Jan 2021 20:39:54 -0800 | From | Jakub Kicinski <> | Subject | Re: [PATCH v1] ipv4: add iPv4_is_multicast() check in ip_mc_leave_group(). |
| |
On Sun, 17 Jan 2021 05:34:16 -0800 wangyingjie55@126.com wrote: > From: Yingjie Wang <wangyingjie55@126.com> > > There is no iPv4_is_multicast() check added to ip_mc_leave_group() > to check if imr->imr_multiaddr.s_addr is a multicast address. > If not a multicast address, it may result in an error.
Could you please say more? From looking at the code it seems like no address should match if group is non-mcast, and -EADDRNOTAVAIL will be returned.
Adding Nik to CC.
> In some cases, the callers of ip_mc_leave_group() don't check > whether it is multicast address or not before calling > such as do_ip_setsockopt(). So I suggest adding the ipv4_is_multicast() > check to the ip_mc_leave_group() to prevent this from happening. > > Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") > Signed-off-by: Yingjie Wang <wangyingjie55@126.com> > --- > net/ipv4/igmp.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c > index 7b272bbed2b4..1b6f91271cfd 100644 > --- a/net/ipv4/igmp.c > +++ b/net/ipv4/igmp.c > @@ -2248,6 +2248,9 @@ int ip_mc_leave_group(struct sock *sk, struct ip_mreqn *imr) > u32 ifindex; > int ret = -EADDRNOTAVAIL; > > + if (!ipv4_is_multicast(group)) > + return -EINVAL; > + > ASSERT_RTNL(); > > in_dev = ip_mc_find_dev(net, imr);
| |