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Date: Wed, 23 Oct 2019 18:39:04 +0200
From: Guillaume Nault <gnault@...hat.com>
To: David Miller <davem@...emloft.net>,
Jakub Kicinski <jakub.kicinski@...ronome.com>
Cc: netdev@...r.kernel.org,
Nicolas Dichtel <nicolas.dichtel@...nd.com>,
Alexei Starovoitov <alexei.starovoitov@...il.com>,
Pravin Shelar <pshelar@....org>, Jiri Benc <jbenc@...hat.com>
Subject: [PATCH net] 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@...hat.com>
---
No changes since RFC.
include/net/net_namespace.h | 2 +-
net/core/dev.c | 2 +-
net/core/net_namespace.c | 17 +++++++++--------
net/core/rtnetlink.c | 14 +++++++-------
net/openvswitch/datapath.c | 20 +++++++++++---------
5 files changed, 29 insertions(+), 26 deletions(-)
diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h
index 4c2cd9378699..c7e15a213ef2 100644
--- a/include/net/net_namespace.h
+++ b/include/net/net_namespace.h
@@ -342,7 +342,7 @@ static inline struct net *read_pnet(const possible_net_t *pnet)
#define __net_initconst __initconst
#endif
-int peernet2id_alloc(struct net *net, struct net *peer);
+int peernet2id_alloc(struct net *net, struct net *peer, gfp_t gfp);
int peernet2id(struct net *net, struct net *peer);
bool peernet_has_id(struct net *net, struct net *peer);
struct net *get_net_ns_by_id(struct net *net, int id);
diff --git a/net/core/dev.c b/net/core/dev.c
index bf3ed413abaf..d966208bc857 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -9460,7 +9460,7 @@ int dev_change_net_namespace(struct net_device *dev, struct net *net, const char
call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
rcu_barrier();
- new_nsid = peernet2id_alloc(dev_net(dev), net);
+ new_nsid = peernet2id_alloc(dev_net(dev), net, GFP_KERNEL);
/* If there is an ifindex conflict assign a new one */
if (__dev_get_by_index(net, dev->ifindex))
new_ifindex = dev_new_index(net);
diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
index 6d3e4821b02d..2f49d5078298 100644
--- a/net/core/net_namespace.c
+++ b/net/core/net_namespace.c
@@ -246,11 +246,11 @@ static int __peernet2id(struct net *net, struct net *peer)
}
static void rtnl_net_notifyid(struct net *net, int cmd, int id, u32 portid,
- struct nlmsghdr *nlh);
+ struct nlmsghdr *nlh, gfp_t gfp);
/* This function returns the id of a peer netns. If no id is assigned, one will
* be allocated and returned.
*/
-int peernet2id_alloc(struct net *net, struct net *peer)
+int peernet2id_alloc(struct net *net, struct net *peer, gfp_t gfp)
{
bool alloc = false, alive = false;
int id;
@@ -269,7 +269,7 @@ int peernet2id_alloc(struct net *net, struct net *peer)
id = __peernet2id_alloc(net, peer, &alloc);
spin_unlock_bh(&net->nsid_lock);
if (alloc && id >= 0)
- rtnl_net_notifyid(net, RTM_NEWNSID, id, 0, NULL);
+ rtnl_net_notifyid(net, RTM_NEWNSID, id, 0, NULL, gfp);
if (alive)
put_net(peer);
return id;
@@ -533,7 +533,8 @@ static void unhash_nsid(struct net *net, struct net *last)
idr_remove(&tmp->netns_ids, id);
spin_unlock_bh(&tmp->nsid_lock);
if (id >= 0)
- rtnl_net_notifyid(tmp, RTM_DELNSID, id, 0, NULL);
+ rtnl_net_notifyid(tmp, RTM_DELNSID, id, 0, NULL,
+ GFP_KERNEL);
if (tmp == last)
break;
}
@@ -766,7 +767,7 @@ static int rtnl_net_newid(struct sk_buff *skb, struct nlmsghdr *nlh,
spin_unlock_bh(&net->nsid_lock);
if (err >= 0) {
rtnl_net_notifyid(net, RTM_NEWNSID, err, NETLINK_CB(skb).portid,
- nlh);
+ nlh, GFP_KERNEL);
err = 0;
} else if (err == -ENOSPC && nsid >= 0) {
err = -EEXIST;
@@ -1054,7 +1055,7 @@ static int rtnl_net_dumpid(struct sk_buff *skb, struct netlink_callback *cb)
}
static void rtnl_net_notifyid(struct net *net, int cmd, int id, u32 portid,
- struct nlmsghdr *nlh)
+ struct nlmsghdr *nlh, gfp_t gfp)
{
struct net_fill_args fillargs = {
.portid = portid,
@@ -1065,7 +1066,7 @@ static void rtnl_net_notifyid(struct net *net, int cmd, int id, u32 portid,
struct sk_buff *msg;
int err = -ENOMEM;
- msg = nlmsg_new(rtnl_net_get_size(), GFP_KERNEL);
+ msg = nlmsg_new(rtnl_net_get_size(), gfp);
if (!msg)
goto out;
@@ -1073,7 +1074,7 @@ static void rtnl_net_notifyid(struct net *net, int cmd, int id, u32 portid,
if (err < 0)
goto err_out;
- rtnl_notify(msg, net, portid, RTNLGRP_NSID, nlh, 0);
+ rtnl_notify(msg, net, portid, RTNLGRP_NSID, nlh, gfp);
return;
err_out:
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 1ee6460f8275..6b866aff7b21 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 @@ static int rtnl_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb)
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))
@@ -3359,7 +3359,7 @@ 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);
@@ -3471,7 +3471,7 @@ 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);
diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c
index f30e406fbec5..d8c364d637b1 100644
--- a/net/openvswitch/datapath.c
+++ b/net/openvswitch/datapath.c
@@ -1881,7 +1881,7 @@ static struct genl_family dp_datapath_genl_family __ro_after_init = {
/* Called with ovs_mutex or RCU read lock. */
static int ovs_vport_cmd_fill_info(struct vport *vport, struct sk_buff *skb,
struct net *net, u32 portid, u32 seq,
- u32 flags, u8 cmd)
+ u32 flags, u8 cmd, gfp_t gfp)
{
struct ovs_header *ovs_header;
struct ovs_vport_stats vport_stats;
@@ -1902,7 +1902,7 @@ static int ovs_vport_cmd_fill_info(struct vport *vport, struct sk_buff *skb,
goto nla_put_failure;
if (!net_eq(net, dev_net(vport->dev))) {
- int id = peernet2id_alloc(net, dev_net(vport->dev));
+ int id = peernet2id_alloc(net, dev_net(vport->dev), gfp);
if (nla_put_s32(skb, OVS_VPORT_ATTR_NETNSID, id))
goto nla_put_failure;
@@ -1943,11 +1943,12 @@ struct sk_buff *ovs_vport_cmd_build_info(struct vport *vport, struct net *net,
struct sk_buff *skb;
int retval;
- skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
+ skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
if (!skb)
return ERR_PTR(-ENOMEM);
- retval = ovs_vport_cmd_fill_info(vport, skb, net, portid, seq, 0, cmd);
+ retval = ovs_vport_cmd_fill_info(vport, skb, net, portid, seq, 0, cmd,
+ GFP_KERNEL);
BUG_ON(retval < 0);
return skb;
@@ -2089,7 +2090,7 @@ static int ovs_vport_cmd_new(struct sk_buff *skb, struct genl_info *info)
err = ovs_vport_cmd_fill_info(vport, reply, genl_info_net(info),
info->snd_portid, info->snd_seq, 0,
- OVS_VPORT_CMD_NEW);
+ OVS_VPORT_CMD_NEW, GFP_KERNEL);
new_headroom = netdev_get_fwd_headroom(vport->dev);
@@ -2150,7 +2151,7 @@ static int ovs_vport_cmd_set(struct sk_buff *skb, struct genl_info *info)
err = ovs_vport_cmd_fill_info(vport, reply, genl_info_net(info),
info->snd_portid, info->snd_seq, 0,
- OVS_VPORT_CMD_SET);
+ OVS_VPORT_CMD_SET, GFP_KERNEL);
BUG_ON(err < 0);
ovs_unlock();
@@ -2190,7 +2191,7 @@ static int ovs_vport_cmd_del(struct sk_buff *skb, struct genl_info *info)
err = ovs_vport_cmd_fill_info(vport, reply, genl_info_net(info),
info->snd_portid, info->snd_seq, 0,
- OVS_VPORT_CMD_DEL);
+ OVS_VPORT_CMD_DEL, GFP_KERNEL);
BUG_ON(err < 0);
/* the vport deletion may trigger dp headroom update */
@@ -2237,7 +2238,7 @@ static int ovs_vport_cmd_get(struct sk_buff *skb, struct genl_info *info)
goto exit_unlock_free;
err = ovs_vport_cmd_fill_info(vport, reply, genl_info_net(info),
info->snd_portid, info->snd_seq, 0,
- OVS_VPORT_CMD_GET);
+ OVS_VPORT_CMD_GET, GFP_ATOMIC);
BUG_ON(err < 0);
rcu_read_unlock();
@@ -2273,7 +2274,8 @@ static int ovs_vport_cmd_dump(struct sk_buff *skb, struct netlink_callback *cb)
NETLINK_CB(cb->skb).portid,
cb->nlh->nlmsg_seq,
NLM_F_MULTI,
- OVS_VPORT_CMD_GET) < 0)
+ OVS_VPORT_CMD_GET,
+ GFP_ATOMIC) < 0)
goto out;
j++;
--
2.21.0
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