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Date:   Tue, 17 Jan 2023 00:57:19 +0100
From:   Piergiorgio Beruto <piergiorgio.beruto@gmail.com>
To:     Andrew Lunn <andrew@lunn.ch>,
        Heiner Kallweit <hkallweit1@gmail.com>,
        Russell King <linux@armlinux.org.uk>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>
Cc:     linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
        Oleksij Rempel <o.rempel@pengutronix.de>,
        mailhol.vincent@wanadoo.fr, sudheer.mogilappagari@intel.com,
        sbhatta@marvell.com, linux-doc@vger.kernel.org,
        wangjie125@huawei.com, corbet@lwn.net, lkp@intel.com,
        gal@nvidia.com, gustavoars@kernel.org, bagasdotme@gmail.com
Subject: [PATCH net-next 1/1] ethtool/plca: fix potential NULL pointer access
Message-ID: <6bb97c2304d9ab499c2831855f6bf3f6ee2b8676.1673913385.git.piergiorgio.beruto@gmail.com>
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Fix problem found by syzbot dereferencing a device pointer.

Signed-off-by: Piergiorgio Beruto <piergiorgio.beruto@gmail.com>
Reported-by: syzbot+8cf35743af243e5f417e@syzkaller.appspotmail.com
Fixes: 8580e16c28f3 ("net/ethtool: add netlink interface for the PLCA RS")
---
 net/ethtool/plca.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/ethtool/plca.c b/net/ethtool/plca.c
index be7404dc9ef2..bc3d31f99998 100644
--- a/net/ethtool/plca.c
+++ b/net/ethtool/plca.c
@@ -155,6 +155,8 @@ int ethnl_set_plca_cfg(struct sk_buff *skb, struct genl_info *info)
 		return ret;
 
 	dev = req_info.dev;
+	if(!dev)
+		return -ENODEV;
 
 	rtnl_lock();
 
-- 
2.37.4