4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Johan Hovold <johan@xxxxxxxxxx> commit 15e0c59f1535926a939d1df66d6edcf997d7c1b9 upstream. Make sure to check the tty-device pointer before trying to access the parent device to avoid dereferencing a NULL-pointer when the tty is one end of a Unix98 pty. Fixes: e097dc624f78 ("NFC: nfcmrvl: add UART driver") Cc: Vincent Cuissard <cuissard@xxxxxxxxxxx> Signed-off-by: Johan Hovold <johan@xxxxxxxxxx> Signed-off-by: Samuel Ortiz <sameo@xxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/nfc/nfcmrvl/uart.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) --- a/drivers/nfc/nfcmrvl/uart.c +++ b/drivers/nfc/nfcmrvl/uart.c @@ -109,6 +109,7 @@ static int nfcmrvl_nci_uart_open(struct struct nfcmrvl_private *priv; struct nfcmrvl_platform_data *pdata = NULL; struct nfcmrvl_platform_data config; + struct device *dev = nu->tty->dev; /* * Platform data cannot be used here since usually it is already used @@ -116,9 +117,8 @@ static int nfcmrvl_nci_uart_open(struct * and check if DT entries were added. */ - if (nu->tty->dev->parent && nu->tty->dev->parent->of_node) - if (nfcmrvl_uart_parse_dt(nu->tty->dev->parent->of_node, - &config) == 0) + if (dev && dev->parent && dev->parent->of_node) + if (nfcmrvl_uart_parse_dt(dev->parent->of_node, &config) == 0) pdata = &config; if (!pdata) { @@ -131,7 +131,7 @@ static int nfcmrvl_nci_uart_open(struct } priv = nfcmrvl_nci_register_dev(NFCMRVL_PHY_UART, nu, &uart_ops, - nu->tty->dev, pdata); + dev, pdata); if (IS_ERR(priv)) return PTR_ERR(priv);