| From: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| Date: Tue, 6 Dec 2016 08:36:29 +0100 |
| Subject: 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 <andreyknvl@google.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com> |
| [bwh: Backported to 3.2: adjust filename] |
| Signed-off-by: Ben Hutchings <ben@decadent.org.uk> |
| --- |
| drivers/usb/gadget/inode.c | 3 ++- |
| 1 file changed, 2 insertions(+), 1 deletion(-) |
| |
| --- a/drivers/usb/gadget/inode.c |
| +++ b/drivers/usb/gadget/inode.c |
| @@ -1861,7 +1861,8 @@ dev_config (struct file *fd, const char |
| 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 */ |
