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Commit fa1ed74e authored by Dan Carpenter's avatar Dan Carpenter Committed by Greg Kroah-Hartman
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USB: devio: Don't corrupt user memory 



The user buffer has "uurb->buffer_length" bytes.  If the kernel has more
information than that, we should truncate it instead of writing past
the end of the user's buffer.  I added a WARN_ONCE() to help the user
debug the issue.

Reported-by: default avatarAlan Stern <stern@rowland.harvard.edu>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: default avatarDan Carpenter <dan.carpenter@oracle.com>
Acked-by: default avatarAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 57999d11

drivers/usb/core/devio.c

+5 −1
Original line number Diff line number Diff line
@@ -1576,7 +1576,11 @@ static int proc_do_submiturb(struct usb_dev_state *ps, struct usbdevfs_urb *uurb 
			totlen += isopkt[u].length;

		}

		u *= sizeof(struct usb_iso_packet_descriptor);

		if (totlen <= uurb->buffer_length)

			uurb->buffer_length = totlen;

		else

			WARN_ONCE(1, "uurb->buffer_length is too short %d vs %d",

				  totlen, uurb->buffer_length);

		break;



	default: