| Message ID | 20120727145822.7efd10d4@griffin |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
From: Jiri Benc <jbenc@redhat.com> Date: Fri, 27 Jul 2012 14:58:22 +0200 > When device flags are set using rtnetlink, IFF_PROMISC and IFF_ALLMULTI > flags are handled specially. Function dev_change_flags sets IFF_PROMISC and > IFF_ALLMULTI bits in dev->gflags according to the passed value but > do_setlink passes a result of rtnl_dev_combine_flags which takes those bits > from dev->flags. > > This can be easily trigerred by doing: > > tcpdump -i eth0 & > ip l s up eth0 > > ip sets IFF_UP flag in ifi_flags and ifi_change, which is combined with > IFF_PROMISC by rtnl_dev_combine_flags, causing __dev_change_flags to set > IFF_PROMISC in gflags. > > Reported-by: Max Matveev <makc@redhat.com> > Signed-off-by: Jiri Benc <jbenc@redhat.com> Applied. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
--- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -659,6 +659,12 @@ static void set_operstate(struct net_dev } } +static unsigned int rtnl_dev_get_flags(const struct net_device *dev) +{ + return (dev->flags & ~(IFF_PROMISC | IFF_ALLMULTI)) | + (dev->gflags & (IFF_PROMISC | IFF_ALLMULTI)); +} + static unsigned int rtnl_dev_combine_flags(const struct net_device *dev, const struct ifinfomsg *ifm) { @@ -667,7 +673,7 @@ static unsigned int rtnl_dev_combine_fla /* bugwards compatibility: ifi_change == 0 is treated as ~0 */ if (ifm->ifi_change) flags = (flags & ifm->ifi_change) | - (dev->flags & ~ifm->ifi_change); + (rtnl_dev_get_flags(dev) & ~ifm->ifi_change); return flags; }
When device flags are set using rtnetlink, IFF_PROMISC and IFF_ALLMULTI flags are handled specially. Function dev_change_flags sets IFF_PROMISC and IFF_ALLMULTI bits in dev->gflags according to the passed value but do_setlink passes a result of rtnl_dev_combine_flags which takes those bits from dev->flags. This can be easily trigerred by doing: tcpdump -i eth0 & ip l s up eth0 ip sets IFF_UP flag in ifi_flags and ifi_change, which is combined with IFF_PROMISC by rtnl_dev_combine_flags, causing __dev_change_flags to set IFF_PROMISC in gflags. Reported-by: Max Matveev <makc@redhat.com> Signed-off-by: Jiri Benc <jbenc@redhat.com> --- net/core/rtnetlink.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html