[media] media: stk1160: Avoid stack-allocated buffer for control URBs

Currently stk1160_read_reg() uses a stack-allocated char to get the
read control value. This is wrong because usb_control_msg() requires
a kmalloc-ed buffer.

This commit fixes such issue by kmalloc'ating a 1-byte buffer to receive
the read value.

While here, let's remove the urb_buf array which was meant for a similar
purpose, but never really used.

Cc: Alan Stern <stern@rowland.harvard.edu>
Reported-by: Sander Eikelenboom <linux@eikelenboom.it>
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Cc: stable@vger.kernel.org      # for v3.7 and up
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

diff --git a/drivers/media/usb/stk1160/stk1160-core.c b/drivers/media/usb/stk1160/stk1160-core.c
index 34a26e0..03504dc 100644 (file)
--- a/drivers/media/usb/stk1160/stk1160-core.c
+++ b/drivers/media/usb/stk1160/stk1160-core.c
@@ -67,17 +67,25 @@ int stk1160_read_reg(struct stk1160 *dev, u16 reg, u8 *value)
 {
        int ret;
        int pipe = usb_rcvctrlpipe(dev->udev, 0);
+       u8 *buf;
 
        *value = 0;
+
+       buf = kmalloc(sizeof(u8), GFP_KERNEL);
+       if (!buf)
+               return -ENOMEM;
        ret = usb_control_msg(dev->udev, pipe, 0x00,
                        USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
-                       0x00, reg, value, sizeof(u8), HZ);
+                       0x00, reg, buf, sizeof(u8), HZ);
        if (ret < 0) {
                stk1160_err("read failed on reg 0x%x (%d)\n",
                        reg, ret);
+               kfree(buf);
                return ret;
        }
 
+       *value = *buf;
+       kfree(buf);
        return 0;
 }
 

diff --git a/drivers/media/usb/stk1160/stk1160.h b/drivers/media/usb/stk1160/stk1160.h
index 05b05b1..abdea48 100644 (file)
--- a/drivers/media/usb/stk1160/stk1160.h
+++ b/drivers/media/usb/stk1160/stk1160.h
@@ -143,7 +143,6 @@ struct stk1160 {
        int num_alt;
 
        struct stk1160_isoc_ctl isoc_ctl;
-       char urb_buf[255];       /* urb control msg buffer */
 
        /* frame properties */
        int width;                /* current frame width */