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authorGuillaume Nault <gnault@redhat.com>2019-10-23 18:39:04 +0200
committerDavid S. Miller <davem@davemloft.net>2019-10-25 20:14:42 -0700
commitd4e4fdf9e4a27c87edb79b1478955075be141f67 (patch)
treee2d2ce489d7a8ee93ae1f2add1e9a73c9ed1aa28 /net/core/rtnetlink.c
parentnet: ethernet: Use the correct style for SPDX License Identifier (diff)
downloadlinux-dev-d4e4fdf9e4a27c87edb79b1478955075be141f67.tar.xz
linux-dev-d4e4fdf9e4a27c87edb79b1478955075be141f67.zip
netns: fix GFP flags in rtnl_net_notifyid()
In rtnl_net_notifyid(), we certainly can't pass a null GFP flag to rtnl_notify(). A GFP_KERNEL flag would be fine in most circumstances, but there are a few paths calling rtnl_net_notifyid() from atomic context or from RCU critical sections. The later also precludes the use of gfp_any() as it wouldn't detect the RCU case. Also, the nlmsg_new() call is wrong too, as it uses GFP_KERNEL unconditionally. Therefore, we need to pass the GFP flags as parameter and propagate it through function calls until the proper flags can be determined. In most cases, GFP_KERNEL is fine. The exceptions are: * openvswitch: ovs_vport_cmd_get() and ovs_vport_cmd_dump() indirectly call rtnl_net_notifyid() from RCU critical section, * rtnetlink: rtmsg_ifinfo_build_skb() already receives GFP flags as parameter. Also, in ovs_vport_cmd_build_info(), let's change the GFP flags used by nlmsg_new(). The function is allowed to sleep, so better make the flags consistent with the ones used in the following ovs_vport_cmd_fill_info() call. Found by code inspection. Fixes: 9a9634545c70 ("netns: notify netns id events") Signed-off-by: Guillaume Nault <gnault@redhat.com> Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Acked-by: Pravin B Shelar <pshelar@ovn.org> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core/rtnetlink.c')
-rw-r--r--net/core/rtnetlink.c14
1 files changed, 7 insertions, 7 deletions
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 13493aae4e6c..ba4b4048ec3e 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -1523,7 +1523,7 @@ static noinline_for_stack int nla_put_ifalias(struct sk_buff *skb,
static int rtnl_fill_link_netnsid(struct sk_buff *skb,
const struct net_device *dev,
- struct net *src_net)
+ struct net *src_net, gfp_t gfp)
{
bool put_iflink = false;
@@ -1531,7 +1531,7 @@ static int rtnl_fill_link_netnsid(struct sk_buff *skb,
struct net *link_net = dev->rtnl_link_ops->get_link_net(dev);
if (!net_eq(dev_net(dev), link_net)) {
- int id = peernet2id_alloc(src_net, link_net);
+ int id = peernet2id_alloc(src_net, link_net, gfp);
if (nla_put_s32(skb, IFLA_LINK_NETNSID, id))
return -EMSGSIZE;
@@ -1589,7 +1589,7 @@ static int rtnl_fill_ifinfo(struct sk_buff *skb,
int type, u32 pid, u32 seq, u32 change,
unsigned int flags, u32 ext_filter_mask,
u32 event, int *new_nsid, int new_ifindex,
- int tgt_netnsid)
+ int tgt_netnsid, gfp_t gfp)
{
struct ifinfomsg *ifm;
struct nlmsghdr *nlh;
@@ -1681,7 +1681,7 @@ static int rtnl_fill_ifinfo(struct sk_buff *skb,
goto nla_put_failure;
}
- if (rtnl_fill_link_netnsid(skb, dev, src_net))
+ if (rtnl_fill_link_netnsid(skb, dev, src_net, gfp))
goto nla_put_failure;
if (new_nsid &&
@@ -2001,7 +2001,7 @@ walk_entries:
NETLINK_CB(cb->skb).portid,
nlh->nlmsg_seq, 0, flags,
ext_filter_mask, 0, NULL, 0,
- netnsid);
+ netnsid, GFP_KERNEL);
if (err < 0) {
if (likely(skb->len))
@@ -3360,7 +3360,7 @@ static int rtnl_getlink(struct sk_buff *skb, struct nlmsghdr *nlh,
err = rtnl_fill_ifinfo(nskb, dev, net,
RTM_NEWLINK, NETLINK_CB(skb).portid,
nlh->nlmsg_seq, 0, 0, ext_filter_mask,
- 0, NULL, 0, netnsid);
+ 0, NULL, 0, netnsid, GFP_KERNEL);
if (err < 0) {
/* -EMSGSIZE implies BUG in if_nlmsg_size */
WARN_ON(err == -EMSGSIZE);
@@ -3472,7 +3472,7 @@ struct sk_buff *rtmsg_ifinfo_build_skb(int type, struct net_device *dev,
err = rtnl_fill_ifinfo(skb, dev, dev_net(dev),
type, 0, 0, change, 0, 0, event,
- new_nsid, new_ifindex, -1);
+ new_nsid, new_ifindex, -1, flags);
if (err < 0) {
/* -EMSGSIZE implies BUG in if_nlmsg_size() */
WARN_ON(err == -EMSGSIZE);