Patch "ieee802154: atusb: do not use the stack for buffers to make them DMA able" has been added to the 4.9-stable tree

Patch "ieee802154: atusb: do not use the stack for buffers to make them DMA able" has been added to the 4.9-stable tree

[gregkh]

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

    ieee802154: atusb: do not use the stack for buffers to make them DMA able

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:
     ieee802154-atusb-do-not-use-the-stack-for-buffers-to-make-them-dma-able.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 <stable@vger.kernel.org> know about it.


>From 05a974efa4bdf6e2a150e3f27dc6fcf0a9ad5655 Mon Sep 17 00:00:00 2001
From: Stefan Schmidt <stefan@osg.samsung.com>
Date: Thu, 15 Dec 2016 18:40:14 +0100
Subject: ieee802154: atusb: do not use the stack for buffers to make them DMA able

From: Stefan Schmidt <stefan@osg.samsung.com>

commit 05a974efa4bdf6e2a150e3f27dc6fcf0a9ad5655 upstream.

>From 4.9 we should really avoid using the stack here as this will not be DMA
able on various platforms. This changes the buffers already being present in
time of 4.9 being released. This should go into stable as well.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Stefan Schmidt <stefan@osg.samsung.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/net/ieee802154/atusb.c |   31 +++++++++++++++++++++++++++----
 1 file changed, 27 insertions(+), 4 deletions(-)

--- a/drivers/net/ieee802154/atusb.c
+++ b/drivers/net/ieee802154/atusb.c
@@ -112,13 +112,26 @@ static int atusb_read_reg(struct atusb *
 {
 	struct usb_device *usb_dev = atusb->usb_dev;
 	int ret;
+	uint8_t *buffer;
 	uint8_t value;
 
+	buffer = kmalloc(1, GFP_KERNEL);
+	if (!buffer)
+		return -ENOMEM;
+
 	dev_dbg(&usb_dev->dev, "atusb: reg = 0x%x\n", reg);
 	ret = atusb_control_msg(atusb, usb_rcvctrlpipe(usb_dev, 0),
 				ATUSB_REG_READ, ATUSB_REQ_FROM_DEV,
-				0, reg, &value, 1, 1000);
-	return ret >= 0 ? value : ret;
+				0, reg, buffer, 1, 1000);
+
+	if (ret >= 0) {
+		value = buffer[0];
+		kfree(buffer);
+		return value;
+	} else {
+		kfree(buffer);
+		return ret;
+	}
 }
 
 static int atusb_write_subreg(struct atusb *atusb, uint8_t reg, uint8_t mask,
@@ -587,9 +600,13 @@ static struct ieee802154_ops atusb_ops =
 static int atusb_get_and_show_revision(struct atusb *atusb)
 {
 	struct usb_device *usb_dev = atusb->usb_dev;
-	unsigned char buffer[3];
+	unsigned char *buffer;
 	int ret;
 
+	buffer = kmalloc(3, GFP_KERNEL);
+	if (!buffer)
+		return -ENOMEM;
+
 	/* Get a couple of the ATMega Firmware values */
 	ret = atusb_control_msg(atusb, usb_rcvctrlpipe(usb_dev, 0),
 				ATUSB_ID, ATUSB_REQ_FROM_DEV, 0, 0,
@@ -605,15 +622,20 @@ static int atusb_get_and_show_revision(s
 		dev_info(&usb_dev->dev, "Please update to version 0.2 or newer");
 	}
 
+	kfree(buffer);
 	return ret;
 }
 
 static int atusb_get_and_show_build(struct atusb *atusb)
 {
 	struct usb_device *usb_dev = atusb->usb_dev;
-	char build[ATUSB_BUILD_SIZE + 1];
+	char *build;
 	int ret;
 
+	build = kmalloc(ATUSB_BUILD_SIZE + 1, GFP_KERNEL);
+	if (!build)
+		return -ENOMEM;
+
 	ret = atusb_control_msg(atusb, usb_rcvctrlpipe(usb_dev, 0),
 				ATUSB_BUILD, ATUSB_REQ_FROM_DEV, 0, 0,
 				build, ATUSB_BUILD_SIZE, 1000);
@@ -622,6 +644,7 @@ static int atusb_get_and_show_build(stru
 		dev_info(&usb_dev->dev, "Firmware: build %s\n", build);
 	}
 
+	kfree(build);
 	return ret;
 }
 


Patches currently in stable-queue which might be from stefan@osg.samsung.com are

queue-4.9/ieee802154-atusb-do-not-use-the-stack-for-buffers-to-make-them-dma-able.patch