From: Greg Kroah-Hartman Date: Tue, 6 Dec 2016 07:36:29 +0000 (+0100) Subject: usb: gadgetfs: restrict upper bound on device configuration size X-Git-Tag: Ubuntu-snapdragon-4.4.0-1047.51~873 X-Git-Url: https://git.proxmox.com/?a=commitdiff_plain;h=6609caea4ae6cd44ae60bab5e28486e92de448fa;p=mirror_ubuntu-zesty-kernel.git usb: gadgetfs: restrict upper bound on device configuration size BugLink: http://bugs.launchpad.net/bugs/1655969 commit 0994b0a257557e18ee8f0b7c5f0f73fe2b54eec1 upstream. Andrey Konovalov reported that we were not properly checking the upper limit before of a device configuration size before calling memdup_user(), which could cause some problems. So set the upper limit to PAGE_SIZE * 4, which should be good enough for all devices. Reported-by: Andrey Konovalov Signed-off-by: Felipe Balbi Signed-off-by: Greg Kroah-Hartman Signed-off-by: Tim Gardner Signed-off-by: Luis Henriques --- diff --git a/drivers/usb/gadget/legacy/inode.c b/drivers/usb/gadget/legacy/inode.c index e57f48f9528f..fa17a8d0f78e 100644 --- a/drivers/usb/gadget/legacy/inode.c +++ b/drivers/usb/gadget/legacy/inode.c @@ -1783,7 +1783,8 @@ dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr) } spin_unlock_irq(&dev->lock); - if (len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4)) + if ((len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4)) || + (len > PAGE_SIZE * 4)) return -EINVAL; /* we might need to change message format someday */