netdev - [RFC net 2/2] netdev-genl: Hold rcu_read_lock in napi

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: <20241112181401.9689-3-jdamato@fastly.com>
Date: Tue, 12 Nov 2024 18:13:59 +0000
From: Joe Damato <jdamato@...tly.com>
To: netdev@...r.kernel.org
Cc: pabeni@...hat.com,
	edumazet@...gle.com,
	amritha.nambiar@...el.com,
	sridhar.samudrala@...el.com,
	kuba@...nel.org,
	mkarsten@...terloo.ca,
	Joe Damato <jdamato@...tly.com>,
	"David S. Miller" <davem@...emloft.net>,
	Simon Horman <horms@...nel.org>,
	Mina Almasry <almasrymina@...gle.com>,
	linux-kernel@...r.kernel.org (open list)
Subject: [RFC net 2/2] netdev-genl: Hold rcu_read_lock in napi_set

Hold rcu_read_lock during netdev_nl_napi_set_doit, which calls
napi_by_id and requires rcu_read_lock to be held.

Add a helper function which calls napi_by_id and sets the error code and
extack. It is used by this commit and the next commit to reduce code
duplication.

Closes: https://lore.kernel.org/netdev/719083c2-e277-447b-b6ea-ca3acb293a03@redhat.com/
Fixes: 1287c1ae0fc2 ("netdev-genl: Support setting per-NAPI config values")
Signed-off-by: Joe Damato <jdamato@...tly.com>
---
 net/core/netdev-genl.c | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/net/core/netdev-genl.c b/net/core/netdev-genl.c
index 934c63a93524..2a04270e9d2d 100644
--- a/net/core/netdev-genl.c
+++ b/net/core/netdev-genl.c
@@ -361,15 +361,13 @@ int netdev_nl_napi_set_doit(struct sk_buff *skb, struct genl_info *info)
 	napi_id = nla_get_u32(info->attrs[NETDEV_A_NAPI_ID]);
 
 	rtnl_lock();
+	rcu_read_lock();
 
-	napi = napi_by_id(napi_id);
-	if (napi) {
+	napi = __do_napi_by_id(napi_id, info, &err);
+	if (!err)
 		err = netdev_nl_napi_set_config(napi, info);
-	} else {
-		NL_SET_BAD_ATTR(info->extack, info->attrs[NETDEV_A_NAPI_ID]);
-		err = -ENOENT;
-	}
 
+	rcu_read_unlock();
 	rtnl_unlock();
 
 	return err;
-- 
2.25.1