Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [ 106/122] net: fix rtnetlink IFF_PROMISC and IFF_ALLMULTI handling | Date | Tue, 7 Aug 2012 15:26:34 -0700 |
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From: Greg KH <gregkh@linuxfoundation.org>
3.5-stable review patch. If anyone has any objections, please let me know.
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From: Jiri Benc <jbenc@redhat.com>
[ Upstream commit b1beb681cba5358f62e6187340660ade226a5fcc ]
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> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- net/core/rtnetlink.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)
--- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -674,6 +674,12 @@ 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) { @@ -682,7 +688,7 @@ 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; }
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