This is a note to let you know that I've just added the patch titled
USB: devio: Don't corrupt user memory
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
usb-devio-don-t-corrupt-user-memory.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From fa1ed74eb1c233be6131ec92df21ab46499a15b6 Mon Sep 17 00:00:00 2001
From: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Date: Fri, 22 Sep 2017 23:43:46 +0300
Subject: USB: devio: Don't corrupt user memory
From: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
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 <stern@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Acked-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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:
Patches currently in stable-queue which might be from dan.carpenter@xxxxxxxxxx are
queue-4.4/usb-devio-don-t-corrupt-user-memory.patch