netfilter: nftables: comment indirect serialization of commit_mutex with rtnl_mutex

Add an explicit comment in the code to describe the indirect
serialization of the holders of the commit_mutex with the rtnl_mutex.
Commit 90d2723c6d ("netfilter: nf_tables: do not hold reference on
netdevice from preparation phase") already describes this, but a comment
in this case is better for reference.

Reported-by: Vladimir Oltean <olteanv@gmail.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Pablo Neira Ayuso 2020-12-08 18:57:02 +01:00
parent 917d80d376
commit 42f1c27120

View File

@ -1723,6 +1723,10 @@ static struct nft_hook *nft_netdev_hook_alloc(struct net *net,
}
nla_strlcpy(ifname, attr, IFNAMSIZ);
/* nf_tables_netdev_event() is called under rtnl_mutex, this is
* indirectly serializing all the other holders of the commit_mutex with
* the rtnl_mutex.
*/
dev = __dev_get_by_name(net, ifname);
if (!dev) {
err = -ENOENT;