From 1992564156b5dc4ac73418e5b95e1a43f12f3cb1 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Thu, 2 Feb 2017 12:36:01 -0200 Subject: [PATCH] dvb-usb-v2: avoid use-after-free commit 005145378c9ad7575a01b6ce1ba118fb427f583a upstream. I ran into a stack frame size warning because of the on-stack copy of the USB device structure: drivers/media/usb/dvb-usb-v2/dvb_usb_core.c: In function 'dvb_usbv2_disconnect': drivers/media/usb/dvb-usb-v2/dvb_usb_core.c:1029:1: error: the frame size of 1104 bytes is larger than 1024 bytes [-Werror=frame-larger-than=] Copying a device structure like this is wrong for a number of other reasons too aside from the possible stack overflow. One of them is that the dev_info() call will print the name of the device later, but AFAICT we have only copied a pointer to the name earlier and the actual name has been freed by the time it gets printed. This removes the on-stack copy of the device and instead copies the device name using kstrdup(). I'm ignoring the possible failure here as both printk() and kfree() are able to deal with NULL pointers. CVE: CVE-2017-8064 Upstream-Status: Backport [backport from: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git/commit/?h=v4.9.51&id=1992564156b5dc4ac73418e5b95e1a43f12f3cb1] Signed-off-by: Arnd Bergmann Signed-off-by: Mauro Carvalho Chehab Cc: Ben Hutchings Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sona Sarmadi --- drivers/media/usb/dvb-usb-v2/dvb_usb_core.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/drivers/media/usb/dvb-usb-v2/dvb_usb_core.c b/drivers/media/usb/dvb-usb-v2/dvb_usb_core.c index a8e6624..a9bb2dd 100644 --- a/drivers/media/usb/dvb-usb-v2/dvb_usb_core.c +++ b/drivers/media/usb/dvb-usb-v2/dvb_usb_core.c @@ -1013,8 +1013,8 @@ int dvb_usbv2_probe(struct usb_interface *intf, void dvb_usbv2_disconnect(struct usb_interface *intf) { struct dvb_usb_device *d = usb_get_intfdata(intf); - const char *name = d->name; - struct device dev = d->udev->dev; + const char *devname = kstrdup(dev_name(&d->udev->dev), GFP_KERNEL); + const char *drvname = d->name; dev_dbg(&d->udev->dev, "%s: bInterfaceNumber=%d\n", __func__, intf->cur_altsetting->desc.bInterfaceNumber); @@ -1024,8 +1024,9 @@ void dvb_usbv2_disconnect(struct usb_interface *intf) dvb_usbv2_exit(d); - dev_info(&dev, "%s: '%s' successfully deinitialized and disconnected\n", - KBUILD_MODNAME, name); + pr_info("%s: '%s:%s' successfully deinitialized and disconnected\n", + KBUILD_MODNAME, drvname, devname); + kfree(devname); } EXPORT_SYMBOL(dvb_usbv2_disconnect); -- 1.9.1