From 697bd634c765667892d21e182792c94c92f813ea Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Wed, 9 Oct 2019 17:38:45 +0200 Subject: [PATCH] USB: chaoskey: fix use-after-free on release commit 93ddb1f56ae102f14f9e46a9a9c8017faa970003 upstream. The driver was accessing its struct usb_interface in its release() callback without holding a reference. This would lead to a use-after-free whenever the device was disconnected while the character device was still open. Fixes: 66e3e591891d ("usb: Add driver for Altus Metrum ChaosKey device (v2)") Cc: stable # 4.1 Signed-off-by: Johan Hovold Link: https://lore.kernel.org/r/20191009153848.8664-3-johan@kernel.org Signed-off-by: Greg Kroah-Hartman --- drivers/usb/misc/chaoskey.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/usb/misc/chaoskey.c b/drivers/usb/misc/chaoskey.c index efecb87428b1..64f2eeffaa00 100644 --- a/drivers/usb/misc/chaoskey.c +++ b/drivers/usb/misc/chaoskey.c @@ -108,6 +108,7 @@ static void chaoskey_free(struct chaoskey *dev) usb_free_urb(dev->urb); kfree(dev->name); kfree(dev->buf); + usb_put_intf(dev->interface); kfree(dev); } } @@ -157,6 +158,8 @@ static int chaoskey_probe(struct usb_interface *interface, if (dev == NULL) goto out; + dev->interface = usb_get_intf(interface); + dev->buf = kmalloc(size, GFP_KERNEL); if (dev->buf == NULL) @@ -190,8 +193,6 @@ static int chaoskey_probe(struct usb_interface *interface, strcat(dev->name, udev->serial); } - dev->interface = interface; - dev->in_ep = in_ep; if (le16_to_cpu(udev->descriptor.idVendor) != ALEA_VENDOR_ID) -- 2.20.1