From b1beb681cba5358f62e6187340660ade226a5fcc Mon Sep 17 00:00:00 2001 From: Jiri Benc Date: Fri, 27 Jul 2012 02:58:22 +0000 Subject: [PATCH] net: fix rtnetlink IFF_PROMISC and IFF_ALLMULTI handling 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 Signed-off-by: Jiri Benc Signed-off-by: David S. Miller --- net/core/rtnetlink.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index 334b930e0de3..bc9e380f0abf 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -659,6 +659,12 @@ static void set_operstate(struct net_device *dev, unsigned char transition) } } +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_flags(const struct net_device *dev, /* 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; } -- 2.20.1