[PATCH 5.15 079/244] plip: avoid rcu debug splat

From: Greg Kroah-Hartman
Date: Tue Aug 23 2022 - 05:55:15 EST


From: Florian Westphal <fw@xxxxxxxxx>

commit bc3c8fe3c79bcdae4d90e3726054fac5cca8ac32 upstream.

WARNING: suspicious RCU usage
5.2.0-rc2-00605-g2638eb8b50cfc #1 Not tainted
drivers/net/plip/plip.c:1110 suspicious rcu_dereference_check() usage!

plip_open is called with RTNL held, switch to the correct helper.

Fixes: 2638eb8b50cf ("net: ipv4: provide __rcu annotation for ifa_list")
Reported-by: kernel test robot <oliver.sang@xxxxxxxxx>
Signed-off-by: Florian Westphal <fw@xxxxxxxxx>
Link: https://lore.kernel.org/r/20220807115304.13257-1-fw@xxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/plip/plip.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/net/plip/plip.c
+++ b/drivers/net/plip/plip.c
@@ -1107,7 +1107,7 @@ plip_open(struct net_device *dev)
/* Any address will do - we take the first. We already
have the first two bytes filled with 0xfc, from
plip_init_dev(). */
- const struct in_ifaddr *ifa = rcu_dereference(in_dev->ifa_list);
+ const struct in_ifaddr *ifa = rtnl_dereference(in_dev->ifa_list);
if (ifa != NULL) {
memcpy(dev->dev_addr+2, &ifa->ifa_local, 4);
}