4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Dan Carpenter <dan.carpen...@oracle.com>
commit fa1ed74eb1c233be6131ec92df21ab46499a15b6 upstream.
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: Alan Stern <st...@rowland.harvard.edu>
Signed-off-by: Dan Carpenter <dan.carpen...@oracle.com>
Acked-by: Alan Stern <st...@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
drivers/usb/core/devio.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
--- a/drivers/usb/core/devio.c
+++ b/drivers/usb/core/devio.c
@@ -1417,7 +1417,11 @@ static int proc_do_submiturb(struct usb_
totlen += isopkt[u].length;
}
u *= sizeof(struct usb_iso_packet_descriptor);
- uurb->buffer_length = totlen;
+ 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:
