From 8ca9418350eccd5dd2659931807c1901224dd638 Mon Sep 17 00:00:00 2001 From: Scott Feldman Date: Fri, 28 May 2010 03:42:18 -0700 Subject: [PATCH] netlink: bug fix: don't overrun skbs on vf_port dump Noticed by Patrick McHardy: was continuing to fill skb after a nla_put_failure, ignoring the size calculated by upper layer. Now, return -EMSGSIZE on any overruns, but also allow netdev to fail ndo_get_vf_port with error other than -EMSGSIZE, thus unwinding nest. Signed-off-by: Scott Feldman Signed-off-by: David S. Miller --- net/core/rtnetlink.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index 7ab86f3a1ea4..7331bb2f6b9c 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -722,14 +722,13 @@ static int rtnl_vf_ports_fill(struct sk_buff *skb, struct net_device *dev) for (vf = 0; vf < dev_num_vf(dev->dev.parent); vf++) { vf_port = nla_nest_start(skb, IFLA_VF_PORT); - if (!vf_port) { - nla_nest_cancel(skb, vf_ports); - return -EMSGSIZE; - } + if (!vf_port) + goto nla_put_failure; NLA_PUT_U32(skb, IFLA_PORT_VF, vf); err = dev->netdev_ops->ndo_get_vf_port(dev, vf, skb); + if (err == -EMSGSIZE) + goto nla_put_failure; if (err) { -nla_put_failure: nla_nest_cancel(skb, vf_port); continue; } @@ -739,6 +738,10 @@ nla_put_failure: nla_nest_end(skb, vf_ports); return 0; + +nla_put_failure: + nla_nest_cancel(skb, vf_ports); + return -EMSGSIZE; } static int rtnl_port_self_fill(struct sk_buff *skb, struct net_device *dev) @@ -753,7 +756,7 @@ static int rtnl_port_self_fill(struct sk_buff *skb, struct net_device *dev) err = dev->netdev_ops->ndo_get_vf_port(dev, PORT_SELF_VF, skb); if (err) { nla_nest_cancel(skb, port_self); - return err; + return (err == -EMSGSIZE) ? err : 0; } nla_nest_end(skb, port_self); -- 2.20.1