netdev-genl: Hold rcu_read_lock in napi_get

Hold rcu_read_lock in netdev_nl_napi_get_doit, which calls napi_by_id
and is required to be called under rcu_read_lock.

Cc: stable@vger.kernel.org
Fixes: 27f91aaf49b3 ("netdev-genl: Add netlink framework functions for napi")
Signed-off-by: Joe Damato <jdamato@fastly.com>
Link: https://patch.msgid.link/20241114175157.16604-1-jdamato@fastly.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/net/core/netdev-genl.c b/net/core/netdev-genl.c
index 1cb954f2d39e8248bffd854cdf27eceb25293425..d2baa1af9df09ec011b8aa25c2d1e49b0714ae22 100644 (file)
--- a/net/core/netdev-genl.c
+++ b/net/core/netdev-genl.c
@@ -215,6 +215,7 @@ int netdev_nl_napi_get_doit(struct sk_buff *skb, struct genl_info *info)
                return -ENOMEM;
 
        rtnl_lock();
+       rcu_read_lock();
 
        napi = napi_by_id(napi_id);
        if (napi) {
@@ -224,6 +225,7 @@ int netdev_nl_napi_get_doit(struct sk_buff *skb, struct genl_info *info)
                err = -ENOENT;
        }
 
+       rcu_read_unlock();
        rtnl_unlock();
 
        if (err)