From 42f1c27120906a54e73101a7d6a12f58813f6a9f Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Tue, 8 Dec 2020 18:57:02 +0100 Subject: 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 90d2723c6d4c ("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 Reviewed-by: Vladimir Oltean Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_tables_api.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index c2f59879a48d..9a080767667b 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -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; -- cgit v1.2.3