From: 추지호 Date: Thu, 8 Dec 2016 12:01:13 +0000 (+0000) Subject: can: peak: fix bad memory access and free sequence X-Git-Tag: v4.8.15~9 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3ee9f16cff18b6a781a7bd1e7ffb9038909977ec;p=thirdparty%2Fkernel%2Fstable.git can: peak: fix bad memory access and free sequence commit b67d0dd7d0dc9e456825447bbeb935d8ef43ea7c upstream. 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 Signed-off-by: Marc Kleine-Budde Signed-off-by: Greg Kroah-Hartman --- 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 bfb91d8fa4605..1006af40481df 100644 --- a/drivers/net/can/usb/peak_usb/pcan_usb_core.c +++ b/drivers/net/can/usb/peak_usb/pcan_usb_core.c @@ -872,23 +872,25 @@ 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); }