[PATCH 6.1.y 2/3] phonet: Pass net and ifindex to phonet_address_notify().

[Sasha Levin <sashal@kernel.org>]

From: Kuniyuki Iwashima <kuniyu@amazon.com>

[ Upstream commit 68ed5c38b512b734caf3da1f87db4a99fcfe3002 ]

Currently, phonet_address_notify() fetches netns and ifindex from dev.

Once addr_doit() is converted to RCU, phonet_address_notify() will be
called outside of RCU due to GFP_KERNEL, and dev will be unavailable
there.

Let's pass net and ifindex to phonet_address_notify().

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Stable-dep-of: 71de0177b28d ("net: phonet: free phonet_device after RCU grace period")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 include/net/phonet/pn_dev.h |  2 +-
 net/phonet/pn_dev.c         | 10 +++++++---
 net/phonet/pn_netlink.c     | 12 ++++++------
 3 files changed, 14 insertions(+), 10 deletions(-)

diff --git a/include/net/phonet/pn_dev.h b/include/net/phonet/pn_dev.h
index e9dc8dca5817b8..6b2102b4ece38a 100644
--- a/include/net/phonet/pn_dev.h
+++ b/include/net/phonet/pn_dev.h
@@ -38,7 +38,7 @@ int phonet_address_add(struct net_device *dev, u8 addr);
 int phonet_address_del(struct net_device *dev, u8 addr);
 u8 phonet_address_get(struct net_device *dev, u8 addr);
 int phonet_address_lookup(struct net *net, u8 addr);
-void phonet_address_notify(int event, struct net_device *dev, u8 addr);
+void phonet_address_notify(struct net *net, int event, u32 ifindex, u8 addr);
 
 int phonet_route_add(struct net_device *dev, u8 daddr);
 int phonet_route_del(struct net_device *dev, u8 daddr);
diff --git a/net/phonet/pn_dev.c b/net/phonet/pn_dev.c
index cde671d29d5dd3..2e7d850dc72668 100644
--- a/net/phonet/pn_dev.c
+++ b/net/phonet/pn_dev.c
@@ -98,10 +98,13 @@ static void phonet_device_destroy(struct net_device *dev)
 	mutex_unlock(&pndevs->lock);
 
 	if (pnd) {
+		struct net *net = dev_net(dev);
+		u32 ifindex = dev->ifindex;
 		u8 addr;
 
 		for_each_set_bit(addr, pnd->addrs, 64)
-			phonet_address_notify(RTM_DELADDR, dev, addr);
+			phonet_address_notify(net, RTM_DELADDR, ifindex, addr);
+
 		kfree(pnd);
 	}
 }
@@ -244,8 +247,9 @@ static int phonet_device_autoconf(struct net_device *dev)
 	ret = phonet_address_add(dev, req.ifr_phonet_autoconf.device);
 	if (ret)
 		return ret;
-	phonet_address_notify(RTM_NEWADDR, dev,
-				req.ifr_phonet_autoconf.device);
+
+	phonet_address_notify(dev_net(dev), RTM_NEWADDR, dev->ifindex,
+			      req.ifr_phonet_autoconf.device);
 	return 0;
 }
 
diff --git a/net/phonet/pn_netlink.c b/net/phonet/pn_netlink.c
index 6b50e4d526682f..c4c9fda4c3de14 100644
--- a/net/phonet/pn_netlink.c
+++ b/net/phonet/pn_netlink.c
@@ -22,7 +22,7 @@
 static int fill_addr(struct sk_buff *skb, u32 ifindex, u8 addr,
 		     u32 portid, u32 seq, int event);
 
-void phonet_address_notify(int event, struct net_device *dev, u8 addr)
+void phonet_address_notify(struct net *net, int event, u32 ifindex, u8 addr)
 {
 	struct sk_buff *skb;
 	int err = -ENOBUFS;
@@ -32,17 +32,17 @@ void phonet_address_notify(int event, struct net_device *dev, u8 addr)
 	if (skb == NULL)
 		goto errout;
 
-	err = fill_addr(skb, dev->ifindex, addr, 0, 0, event);
+	err = fill_addr(skb, ifindex, addr, 0, 0, event);
 	if (err < 0) {
 		WARN_ON(err == -EMSGSIZE);
 		kfree_skb(skb);
 		goto errout;
 	}
-	rtnl_notify(skb, dev_net(dev), 0,
-		    RTNLGRP_PHONET_IFADDR, NULL, GFP_KERNEL);
+
+	rtnl_notify(skb, net, 0, RTNLGRP_PHONET_IFADDR, NULL, GFP_KERNEL);
 	return;
 errout:
-	rtnl_set_sk_err(dev_net(dev), RTNLGRP_PHONET_IFADDR, err);
+	rtnl_set_sk_err(net, RTNLGRP_PHONET_IFADDR, err);
 }
 
 static const struct nla_policy ifa_phonet_policy[IFA_MAX+1] = {
@@ -89,7 +89,7 @@ static int addr_doit(struct sk_buff *skb, struct nlmsghdr *nlh,
 	else
 		err = phonet_address_del(dev, pnaddr);
 	if (!err)
-		phonet_address_notify(nlh->nlmsg_type, dev, pnaddr);
+		phonet_address_notify(net, nlh->nlmsg_type, ifm->ifa_index, pnaddr);
 	return err;
 }
 
-- 
2.53.0