From 644d0a5bcc3361170d84fb8d0b13943c354119db Mon Sep 17 00:00:00 2001 From: Tong Zhang Date: Mon, 6 Sep 2021 16:37:02 -0700 Subject: [PATCH] can: c_can: fix null-ptr-deref on ioctl() The pdev maybe not a platform device, e.g. c_can_pci device, in this case, calling to_platform_device() would not make sense. Also, per the comment in drivers/net/can/c_can/c_can_ethtool.c, @bus_info should match dev_name() string, so I am replacing this with dev_name() to fix this issue. [ 1.458583] BUG: unable to handle page fault for address: 0000000100000000 [ 1.460921] RIP: 0010:strnlen+0x1a/0x30 [ 1.466336] ? c_can_get_drvinfo+0x65/0xb0 [c_can] [ 1.466597] ethtool_get_drvinfo+0xae/0x360 [ 1.466826] dev_ethtool+0x10f8/0x2970 [ 1.467880] sock_ioctl+0xef/0x300 Fixes: 2722ac986e93 ("can: c_can: add ethtool support") Link: https://lore.kernel.org/r/20210906233704.1162666-1-ztong0001@gmail.com Cc: stable@vger.kernel.org # 5.14+ Signed-off-by: Tong Zhang Signed-off-by: Marc Kleine-Budde --- drivers/net/can/c_can/c_can_ethtool.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/drivers/net/can/c_can/c_can_ethtool.c b/drivers/net/can/c_can/c_can_ethtool.c index cd5f07fca2a5..377c7d2e7612 100644 --- a/drivers/net/can/c_can/c_can_ethtool.c +++ b/drivers/net/can/c_can/c_can_ethtool.c @@ -15,10 +15,8 @@ static void c_can_get_drvinfo(struct net_device *netdev, struct ethtool_drvinfo *info) { struct c_can_priv *priv = netdev_priv(netdev); - struct platform_device *pdev = to_platform_device(priv->device); - strscpy(info->driver, "c_can", sizeof(info->driver)); - strscpy(info->bus_info, pdev->name, sizeof(info->bus_info)); + strscpy(info->bus_info, dev_name(priv->device), sizeof(info->bus_info)); } static void c_can_get_ringparam(struct net_device *netdev,