From a5bc01949e3b19d8a23b5eabc6fc71bb50dc820e Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Tue, 3 Jan 2017 16:39:58 +0100 Subject: [PATCH] USB: serial: omninet: fix NULL-derefs at open and disconnect Fix NULL-pointer dereferences at open() and disconnect() should the device lack the expected bulk-out endpoints: Unable to handle kernel NULL pointer dereference at virtual address 000000b4 ... [c0170ff0>] (__lock_acquire) from [] (lock_acquire+0x108/0x264) [] (lock_acquire) from [] (_raw_spin_lock_irqsave+0x58/0x6c) [] (_raw_spin_lock_irqsave) from [] (tty_port_tty_set+0x28/0xa4) [] (tty_port_tty_set) from [] (omninet_open+0x30/0x40 [omninet]) [] (omninet_open [omninet]) from [] (serial_port_activate+0x68/0x98 [usbserial]) Unable to handle kernel NULL pointer dereference at virtual address 00000234 ... [] (omninet_disconnect [omninet]) from [] (usb_serial_disconnect+0xe4/0x100 [usbserial]) Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable Signed-off-by: Johan Hovold --- drivers/usb/serial/omninet.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/drivers/usb/serial/omninet.c b/drivers/usb/serial/omninet.c index f6c6900bccf0..a180b17d2432 100644 --- a/drivers/usb/serial/omninet.c +++ b/drivers/usb/serial/omninet.c @@ -38,6 +38,7 @@ static int omninet_write(struct tty_struct *tty, struct usb_serial_port *port, const unsigned char *buf, int count); static int omninet_write_room(struct tty_struct *tty); static void omninet_disconnect(struct usb_serial *serial); +static int omninet_attach(struct usb_serial *serial); static int omninet_port_probe(struct usb_serial_port *port); static int omninet_port_remove(struct usb_serial_port *port); @@ -56,6 +57,7 @@ static struct usb_serial_driver zyxel_omninet_device = { .description = "ZyXEL - omni.net lcd plus usb", .id_table = id_table, .num_ports = 1, + .attach = omninet_attach, .port_probe = omninet_port_probe, .port_remove = omninet_port_remove, .open = omninet_open, @@ -104,6 +106,17 @@ struct omninet_data { __u8 od_outseq; /* Sequence number for bulk_out URBs */ }; +static int omninet_attach(struct usb_serial *serial) +{ + /* The second bulk-out endpoint is used for writing. */ + if (serial->num_bulk_out < 2) { + dev_err(&serial->interface->dev, "missing endpoints\n"); + return -ENODEV; + } + + return 0; +} + static int omninet_port_probe(struct usb_serial_port *port) { struct omninet_data *od; -- 2.20.1