From 0994b0a257557e18ee8f0b7c5f0f73fe2b54eec1 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Tue, 6 Dec 2016 08:36:29 +0100 Subject: [PATCH] usb: gadgetfs: restrict upper bound on device configuration size 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 Cc: stable Signed-off-by: Greg Kroah-Hartman Signed-off-by: Felipe Balbi --- drivers/usb/gadget/legacy/inode.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/usb/gadget/legacy/inode.c b/drivers/usb/gadget/legacy/inode.c index e8f4102d19df..48f1409b438a 100644 --- a/drivers/usb/gadget/legacy/inode.c +++ b/drivers/usb/gadget/legacy/inode.c @@ -1762,7 +1762,8 @@ 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 */ -- 2.20.1