diff mbox series

[2/5] USB: chaoskey: fix use-after-free on release

Message ID 20191009153848.8664-3-johan@kernel.org (mailing list archive)
State Mainlined
Commit 93ddb1f56ae102f14f9e46a9a9c8017faa970003
Headers show
Series USB: misc: fix disconnect bugs | expand

Commit Message

Johan Hovold Oct. 9, 2019, 3:38 p.m. UTC 
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 <stable@vger.kernel.org>     # 4.1
Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/usb/misc/chaoskey.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/drivers/usb/misc/chaoskey.c b/drivers/usb/misc/chaoskey.c
index cf5828ce927a..34e6cd6f40d3 100644
--- a/drivers/usb/misc/chaoskey.c
+++ b/drivers/usb/misc/chaoskey.c
@@ -98,6 +98,7 @@  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);
 	}
 }
@@ -145,6 +146,8 @@  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)
@@ -174,8 +177,6 @@  static int chaoskey_probe(struct usb_interface *interface,
 			goto out;
 	}
 
-	dev->interface = interface;
-
 	dev->in_ep = in_ep;
 
 	if (le16_to_cpu(udev->descriptor.idVendor) != ALEA_VENDOR_ID)