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: v3.10.107~226 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=133caaf57f3b8b57db1aa3fca3d343f3672fdf1a;p=thirdparty%2Fkernel%2Fstable.git usb: gadgetfs: restrict upper bound on device configuration size 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: Willy Tarreau --- diff --git a/drivers/usb/gadget/inode.c b/drivers/usb/gadget/inode.c index 42a30903d4fd9..5b45429da13b7 100644 --- a/drivers/usb/gadget/inode.c +++ b/drivers/usb/gadget/inode.c @@ -1854,7 +1854,8 @@ dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr) u32 tag; char *kbuf; - 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 */