From b67d0dd7d0dc9e456825447bbeb935d8ef43ea7c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=EC=B6=94=EC=A7=80=ED=98=B8?= <jiho.chu@samsung.com>
Date: Thu, 8 Dec 2016 12:01:13 +0000
Subject: [PATCH] can: peak: fix bad memory access and free sequence
Fix for bad memory access while disconnecting. netdev is freed before
private data free, and dev is accessed after freeing netdev.
This makes a slub problem, and it raise kernel oops with slub debugger
config.
Signed-off-by: Jiho Chu <jiho.chu@samsung.com>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
drivers/net/can/usb/peak_usb/pcan_usb_core.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/net/can/usb/peak_usb/pcan_usb_core.c b/drivers/net/can/usb/peak_usb/pcan_usb_core.c
index f3141ca56bc395..0b0302af3bd2dc 100644
--- a/drivers/net/can/usb/peak_usb/pcan_usb_core.c
+++ b/drivers/net/can/usb/peak_usb/pcan_usb_core.c
@@ -870,23 +870,25 @@ lbl_free_candev:
static void peak_usb_disconnect(struct usb_interface *intf)
{
struct peak_usb_device *dev;
+ struct peak_usb_device *dev_prev_siblings;
/* unregister as many netdev devices as siblings */
- for (dev = usb_get_intfdata(intf); dev; dev = dev->prev_siblings) {
+ for (dev = usb_get_intfdata(intf); dev; dev = dev_prev_siblings) {
struct net_device *netdev = dev->netdev;
char name[IFNAMSIZ];
+ dev_prev_siblings = dev->prev_siblings;
dev->state &= ~PCAN_USB_STATE_CONNECTED;
strncpy(name, netdev->name, IFNAMSIZ);
unregister_netdev(netdev);
- free_candev(netdev);
kfree(dev->cmd_buf);
dev->next_siblings = NULL;
if (dev->adapter->dev_free)
dev->adapter->dev_free(dev);
+ free_candev(netdev);
dev_info(&intf->dev, "%s removed\n", name);
}
--
GitLab