[PATCH net] plip: avoid rcu debug splat

[PATCH net] plip: avoid rcu debug splat

[Florian Westphal]

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@intel.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
---
 drivers/net/plip/plip.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/plip/plip.c b/drivers/net/plip/plip.c
index dafd3e9ebbf8..c8791e9b451d 100644
--- a/drivers/net/plip/plip.c
+++ b/drivers/net/plip/plip.c
@@ -1111,7 +1111,7 @@ 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) {
 			dev_addr_mod(dev, 2, &ifa->ifa_local, 4);
 		}
-- 
2.37.1

Re: [PATCH net] plip: avoid rcu debug splat

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net.git (master)
by Jakub Kicinski <kuba@kernel.org>:

On Sun,  7 Aug 2022 13:53:04 +0200 you wrote:
> 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@intel.com>
> Signed-off-by: Florian Westphal <fw@strlen.de>
> 
> [...]

Here is the summary with links:
  - [net] plip: avoid rcu debug splat
    https://git.kernel.org/netdev/net/c/bc3c8fe3c79b

You are awesome, thank you!
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