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: v3.2.87~142 X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?p=pandora-kernel.git;a=commitdiff_plain;h=510c84bdb87fa39b163317be8f3725a10c5aa186 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: Greg Kroah-Hartman Signed-off-by: Felipe Balbi [bwh: Backported to 3.2: adjust filename] Signed-off-by: Ben Hutchings --- diff --git a/drivers/usb/gadget/inode.c b/drivers/usb/gadget/inode.c index ce7253bfaa95..4fac178607ba 100644 --- a/drivers/usb/gadget/inode.c +++ b/drivers/usb/gadget/inode.c @@ -1861,7 +1861,8 @@ 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 */