lkml.org 
[lkml]   [2016]   [Jan]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] xen: fix potential integer overflow in queue_reply
On 18/01/16 16:29, Insu Yun wrote:
> When len is greater than UINT_MAX - sizeof(*rb), in next allocation,
> it can overflow integer range and allocates small size of heap.
> After that, memcpy will overflow the allocated heap.
> Therefore, it needs to check the size of given length.
[...]
> --- a/drivers/xen/xenbus/xenbus_dev_frontend.c
> +++ b/drivers/xen/xenbus/xenbus_dev_frontend.c
> @@ -186,7 +186,7 @@ static int queue_reply(struct list_head *queue, const void *data, size_t len)
> {
> struct read_buffer *rb;
>
> - if (len == 0)
> + if (len == 0 || len >= UINT_MAX - sizeof(*rb))
^^^^^^^^^^^^^^^^^^^^^^
Please check

len > XENSTORE_PAYLOAD_MAX

instead.

David

\
 
 \ /
  Last update: 2016-01-18 18:01    [W:0.033 / U:0.584 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site