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Patch "[media] dvb-usb-firmware: don't do DMA on stack" has been added to the 4.9-stable tree

PATCH [email protected] 1 participant 1 message Apr 19, 2017

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This is a note to let you know that I've just added the patch titled

[media] dvb-usb-firmware: don't do DMA on stack

to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
dvb-usb-firmware-don-t-do-dma-on-stack.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

Quoted 1 line

From 67b0503db9c29b04eadfeede6bebbfe5ddad94ef Mon Sep 17 00:00:00 2001

From: =?UTF-8?q?Stefan=20Br=C3=BCns?= <[email protected]>
Date: Sun, 12 Feb 2017 13:02:13 -0200
Subject: [media] dvb-usb-firmware: don't do DMA on stack
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

From: Stefan Brüns <[email protected]>

commit 67b0503db9c29b04eadfeede6bebbfe5ddad94ef upstream.

The buffer allocation for the firmware data was changed in commit 43fab9793c1f ("[media] dvb-usb: don't use stack for firmware load") but the same applies for the reset value.

Fixes 43fab9793c1f ("[media] dvb-usb: don't use stack for firmware load")
Signed-off-by Stefan Brüns <[email protected]>
Signed-off-by Mauro Carvalho Chehab <[email protected]>
Cc Ben Hutchings <[email protected]>
Cc Brad Spengler <[email protected]>
Signed-off-by Greg Kroah-Hartman <[email protected]>
---
 drivers/media/usb/dvb-usb/dvb-usb-firmware.c |   22 ++++++++++++----------
 1 file changed, 12 insertions(+), 10 deletions(-)
drivers/media/usb/dvb-usb/dvb-usb-firmware.c +12 -10
@@ -36,16 +36,18 @@ static int usb_cypress_writemem(struct u
 int usb_cypress_load_firmware(struct usb_device *udev, const struct firmware *fw, int type)
 {
 	struct hexline *hx;
-	u8 reset;
-	int ret,pos=0;
+	u8 *buf;
+	int ret, pos = 0;
+	u16 cpu_cs_register = cypress[type].cpu_cs_register;
 
-	hx = kmalloc(sizeof(*hx), GFP_KERNEL);
-	if (!hx)
+	buf = kmalloc(sizeof(*hx), GFP_KERNEL);
+	if (!buf)
 		return -ENOMEM;
+	hx = (struct hexline *)buf;
 
 	/* stop the CPU */
-	reset = 1;
-	if ((ret = usb_cypress_writemem(udev,cypress[type].cpu_cs_register,&reset,1)) != 1)
+	buf[0] = 1;
+	if (usb_cypress_writemem(udev, cpu_cs_register, buf, 1) != 1)
 		err("could not stop the USB controller CPU.");
 
 	while ((ret = dvb_usb_get_hexline(fw, hx, &pos)) > 0) {

@@ -62,21 +64,21 @@ int usb_cypress_load_firmware(struct usb
 	}
 	if (ret < 0) {
 		err("firmware download failed at %d with %d",pos,ret);
-		kfree(hx);
+		kfree(buf);
 		return ret;
 	}
 
 	if (ret == 0) {
 		/* restart the CPU */
-		reset = 0;
-		if (ret || usb_cypress_writemem(udev,cypress[type].cpu_cs_register,&reset,1) != 1) {
+		buf[0] = 0;
+		if (usb_cypress_writemem(udev, cpu_cs_register, buf, 1) != 1) {
 			err("could not restart the USB controller CPU.");
 			ret = -EINVAL;
 		}
 	} else
 		ret = -EIO;
 
-	kfree(hx);
+	kfree(buf);
 
 	return ret;
 }

Patches currently in stable-queue which might be from [email protected] are

queue-4.9/dvb-usb-firmware-don-t-do-dma-on-stack.patch queue-4.9/cxusb-use-a-dma-capable-buffer-also-for-reading.patch