From: Yuyang Huang <yuyanghuang@google.com>
Date: Sat, 21 Dec 2024 10:00:07 +0000 (+0900)
Subject: netlink: correct nlmsg size for multicast notifications
X-Git-Tag: v6.14-rc1~162^2~160
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=aa4ad7c3f283fa94b80cf84605661700aa39d708;p=thirdparty%2Fkernel%2Flinux.git

netlink: correct nlmsg size for multicast notifications

Corrected the netlink message size calculation for multicast group
join/leave notifications. The previous calculation did not account for
the inclusion of both IPv4/IPv6 addresses and ifa_cacheinfo in the
payload. This fix ensures that the allocated message size is
sufficient to hold all necessary information.

This patch also includes the following improvements:
* Uses GFP_KERNEL instead of GFP_ATOMIC when holding the RTNL mutex.
* Uses nla_total_size(sizeof(struct in6_addr)) instead of
  nla_total_size(16).
* Removes unnecessary EXPORT_SYMBOL().

Fixes: 2c2b61d2138f ("netlink: add IGMP/MLD join/leave notifications")
Cc: Maciej Żenczykowski <maze@google.com>
Cc: Lorenzo Colitti <lorenzo@google.com>
Signed-off-by: Yuyang Huang <yuyanghuang@google.com>
Link: https://patch.msgid.link/20241221100007.1910089-1-yuyanghuang@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---

diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c
index 8a370ef37d3f6..3da126cea884d 100644
--- a/net/ipv4/igmp.c
+++ b/net/ipv4/igmp.c
@@ -1473,7 +1473,9 @@ static void inet_ifmcaddr_notify(struct net_device *dev,
 	int err = -ENOMEM;
 
 	skb = nlmsg_new(NLMSG_ALIGN(sizeof(struct ifaddrmsg)) +
-			nla_total_size(sizeof(__be32)), GFP_ATOMIC);
+			nla_total_size(sizeof(__be32)) +
+			nla_total_size(sizeof(struct ifa_cacheinfo)),
+			GFP_KERNEL);
 	if (!skb)
 		goto error;
 
@@ -1484,7 +1486,7 @@ static void inet_ifmcaddr_notify(struct net_device *dev,
 		goto error;
 	}
 
-	rtnl_notify(skb, net, 0, RTNLGRP_IPV4_MCADDR, NULL, GFP_ATOMIC);
+	rtnl_notify(skb, net, 0, RTNLGRP_IPV4_MCADDR, NULL, GFP_KERNEL);
 	return;
 error:
 	rtnl_set_sk_err(net, RTNLGRP_IPV4_MCADDR, err);
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 2e2684886953d..4da409bc45777 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -5239,7 +5239,6 @@ int inet6_fill_ifmcaddr(struct sk_buff *skb,
 	nlmsg_end(skb, nlh);
 	return 0;
 }
-EXPORT_SYMBOL(inet6_fill_ifmcaddr);
 
 static int inet6_fill_ifacaddr(struct sk_buff *skb,
 			       const struct ifacaddr6 *ifaca,
diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c
index 587831c148dee..9dfdb40988b0f 100644
--- a/net/ipv6/mcast.c
+++ b/net/ipv6/mcast.c
@@ -920,7 +920,9 @@ static void inet6_ifmcaddr_notify(struct net_device *dev,
 	int err = -ENOMEM;
 
 	skb = nlmsg_new(NLMSG_ALIGN(sizeof(struct ifaddrmsg)) +
-			nla_total_size(16), GFP_ATOMIC);
+			nla_total_size(sizeof(struct in6_addr)) +
+			nla_total_size(sizeof(struct ifa_cacheinfo)),
+			GFP_KERNEL);
 	if (!skb)
 		goto error;
 
@@ -931,7 +933,7 @@ static void inet6_ifmcaddr_notify(struct net_device *dev,
 		goto error;
 	}
 
-	rtnl_notify(skb, net, 0, RTNLGRP_IPV6_MCADDR, NULL, GFP_ATOMIC);
+	rtnl_notify(skb, net, 0, RTNLGRP_IPV6_MCADDR, NULL, GFP_KERNEL);
 	return;
 error:
 	rtnl_set_sk_err(net, RTNLGRP_IPV6_MCADDR, err);