From ef6c8c1d733e244f0499035be0dabe1f4ed98c6f Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Tue, 13 Aug 2013 13:27:34 +0200 Subject: [PATCH] USB: mos7720: fix broken control requests The parallel-port code of the drivers used a stack allocated control-request buffer for asynchronous (and possibly deferred) control requests. This not only violates the no-DMA-from-stack requirement but could also lead to corrupt control requests being submitted. Cc: stable@vger.kernel.org Signed-off-by: Johan Hovold Signed-off-by: Greg Kroah-Hartman --- drivers/usb/serial/mos7720.c | 21 ++++++++++++++------- 1 file changed, 14 insertions(+), 7 deletions(-) diff --git a/drivers/usb/serial/mos7720.c b/drivers/usb/serial/mos7720.c index 51da424327b0..b01300164fc0 100644 --- a/drivers/usb/serial/mos7720.c +++ b/drivers/usb/serial/mos7720.c @@ -90,6 +90,7 @@ struct urbtracker { struct list_head urblist_entry; struct kref ref_count; struct urb *urb; + struct usb_ctrlrequest *setup; }; enum mos7715_pp_modes { @@ -271,6 +272,7 @@ static void destroy_urbtracker(struct kref *kref) struct mos7715_parport *mos_parport = urbtrack->mos_parport; usb_free_urb(urbtrack->urb); + kfree(urbtrack->setup); kfree(urbtrack); kref_put(&mos_parport->ref_count, destroy_mos_parport); } @@ -355,7 +357,6 @@ static int write_parport_reg_nonblock(struct mos7715_parport *mos_parport, struct urbtracker *urbtrack; int ret_val; unsigned long flags; - struct usb_ctrlrequest setup; struct usb_serial *serial = mos_parport->serial; struct usb_device *usbdev = serial->dev; @@ -373,14 +374,20 @@ static int write_parport_reg_nonblock(struct mos7715_parport *mos_parport, kfree(urbtrack); return -ENOMEM; } - setup.bRequestType = (__u8)0x40; - setup.bRequest = (__u8)0x0e; - setup.wValue = get_reg_value(reg, dummy); - setup.wIndex = get_reg_index(reg); - setup.wLength = 0; + urbtrack->setup = kmalloc(sizeof(*urbtrack->setup), GFP_KERNEL); + if (!urbtrack->setup) { + usb_free_urb(urbtrack->urb); + kfree(urbtrack); + return -ENOMEM; + } + urbtrack->setup->bRequestType = (__u8)0x40; + urbtrack->setup->bRequest = (__u8)0x0e; + urbtrack->setup->wValue = get_reg_value(reg, dummy); + urbtrack->setup->wIndex = get_reg_index(reg); + urbtrack->setup->wLength = 0; usb_fill_control_urb(urbtrack->urb, usbdev, usb_sndctrlpipe(usbdev, 0), - (unsigned char *)&setup, + (unsigned char *)urbtrack->setup, NULL, 0, async_complete, urbtrack); kref_init(&urbtrack->ref_count); INIT_LIST_HEAD(&urbtrack->urblist_entry); -- 2.39.5