| Message ID | 20180108142107.29045-1-oneukum@suse.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
diff --git a/drivers/media/usb/usbtv/usbtv-core.c b/drivers/media/usb/usbtv/usbtv-core.c index 127f8a0c098b..0c2e628e8723 100644 --- a/drivers/media/usb/usbtv/usbtv-core.c +++ b/drivers/media/usb/usbtv/usbtv-core.c @@ -112,6 +112,8 @@ static int usbtv_probe(struct usb_interface *intf, return 0; usbtv_audio_fail: + /* we must not free at this point */ + usb_get_dev(usbtv->udev); usbtv_video_free(usbtv); usbtv_video_fail:
Quoting the original report: It looks like there is a double-free vulnerability in Linux usbtv driver on an error path of usbtv_probe function. When audio registration fails, usbtv_video_free function ends up freeing usbtv data structure, which gets freed the second time under usbtv_video_fail label. usbtv_audio_fail: usbtv_video_free(usbtv); => v4l2_device_put(&usbtv->v4l2_dev); => v4l2_device_put => kref_put => v4l2_device_release => usbtv_release (CALLBACK) => kfree(usbtv) (1st time) usbtv_video_fail: usb_set_intfdata(intf, NULL); usb_put_dev(usbtv->udev); kfree(usbtv); (2nd time) So, as we have refcounting, use it Reported-by: Yavuz, Tuba <tuba@ece.ufl.edu> Signed-off-by: Oliver Neukum <oneukum@suse.com> CC: stable@vger.kernel.org --- drivers/media/usb/usbtv/usbtv-core.c | 2 ++ 1 file changed, 2 insertions(+)