netdev - [patch net-next v3 5/9] genetlink: implement release callback and free sk_user

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20231120084657.458076-6-jiri@resnulli.us>
Date: Mon, 20 Nov 2023 09:46:53 +0100
From: Jiri Pirko <jiri@...nulli.us>
To: netdev@...r.kernel.org
Cc: kuba@...nel.org,
	pabeni@...hat.com,
	davem@...emloft.net,
	edumazet@...gle.com,
	jacob.e.keller@...el.com,
	jhs@...atatu.com,
	johannes@...solutions.net,
	andriy.shevchenko@...ux.intel.com,
	amritha.nambiar@...el.com,
	sdf@...gle.com,
	horms@...nel.org
Subject: [patch net-next v3 5/9] genetlink: implement release callback and free sk_user_data there

From: Jiri Pirko <jiri@...dia.com>

If any generic netlink family would like to allocate data store the
pointer to sk_user_data, there is no way to do cleanup in the family
code.

Assume that kfree() is good for now, as the only user introduced by the
follow-up patch (devlink) will use kzalloc() for the allocation of
the memory pointed by a pointer stored in sk_user_data. If later on
this needs to be implemented per-family, a callback is going
to be needed. Until then (if ever), do this in a simple way.

Signed-off-by: Jiri Pirko <jiri@...dia.com>
---
 net/netlink/genetlink.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c
index 92ef5ed2e7b0..905c5a167f53 100644
--- a/net/netlink/genetlink.c
+++ b/net/netlink/genetlink.c
@@ -1699,12 +1699,18 @@ static int genl_bind(struct net *net, int group)
 	return ret;
 }
 
+static void genl_release(struct sock *sk, unsigned long *groups)
+{
+	kfree(sk->sk_user_data);
+}
+
 static int __net_init genl_pernet_init(struct net *net)
 {
 	struct netlink_kernel_cfg cfg = {
 		.input		= genl_rcv,
 		.flags		= NL_CFG_F_NONROOT_RECV,
 		.bind		= genl_bind,
+		.release	= genl_release,
 	};
 
 	/* we'll bump the group number right afterwards */
-- 
2.41.0