From e9e7e85d75f3731079ffd77c1a66f037aef04fe7 Mon Sep 17 00:00:00 2001 From: Nicolas Dichtel Date: Mon, 15 Jul 2019 12:00:20 +0200 Subject: xfrm interface: avoid corruption on changelink The new parameters must not be stored in the netdev_priv() before validation, it may corrupt the interface. Note also that if data is NULL, only a memset() is done. $ ip link add xfrm1 type xfrm dev lo if_id 1 $ ip link add xfrm2 type xfrm dev lo if_id 2 $ ip link set xfrm1 type xfrm dev lo if_id 2 RTNETLINK answers: File exists $ ip -d link list dev xfrm1 5: xfrm1@lo: mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000 link/none 00:00:00:00:00:00 brd 00:00:00:00:00:00 promiscuity 0 minmtu 68 maxmtu 1500 xfrm if_id 0x2 addrgenmode eui64 numtxqueues 1 numrxqueues 1 gso_max_size 65536 gso_max_segs 65535 => "if_id 0x2" Fixes: f203b76d7809 ("xfrm: Add virtual xfrm interfaces") Signed-off-by: Nicolas Dichtel Tested-by: Julien Floret Signed-off-by: Steffen Klassert --- net/xfrm/xfrm_interface.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'net/xfrm') diff --git a/net/xfrm/xfrm_interface.c b/net/xfrm/xfrm_interface.c index 74868f9d81fb..2310dc9e35c2 100644 --- a/net/xfrm/xfrm_interface.c +++ b/net/xfrm/xfrm_interface.c @@ -671,12 +671,12 @@ static int xfrmi_changelink(struct net_device *dev, struct nlattr *tb[], struct nlattr *data[], struct netlink_ext_ack *extack) { - struct xfrm_if *xi = netdev_priv(dev); struct net *net = dev_net(dev); + struct xfrm_if_parms p; + struct xfrm_if *xi; - xfrmi_netlink_parms(data, &xi->p); - - xi = xfrmi_locate(net, &xi->p); + xfrmi_netlink_parms(data, &p); + xi = xfrmi_locate(net, &p); if (!xi) { xi = netdev_priv(dev); } else { @@ -684,7 +684,7 @@ static int xfrmi_changelink(struct net_device *dev, struct nlattr *tb[], return -EEXIST; } - return xfrmi_update(xi, &xi->p); + return xfrmi_update(xi, &p); } static size_t xfrmi_get_size(const struct net_device *dev) -- cgit v1.2.3