lkml.org 
[lkml]   [2014]   [Jun]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 3.15 112/139] aio: fix kernel memory disclosure in io_getevents() introduced in v3.10
Date
3.15-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Benjamin LaHaise <bcrl@kvack.org>

commit edfbbf388f293d70bf4b7c0bc38774d05e6f711a upstream.

A kernel memory disclosure was introduced in aio_read_events_ring() in v3.10
by commit a31ad380bed817aa25f8830ad23e1a0480fef797. The changes made to
aio_read_events_ring() failed to correctly limit the index into
ctx->ring_pages[], allowing an attacked to cause the subsequent kmap() of
an arbitrary page with a copy_to_user() to copy the contents into userspace.
This vulnerability has been assigned CVE-2014-0206. Thanks to Mateusz and
Petr for disclosing this issue.

This patch applies to v3.12+. A separate backport is needed for 3.10/3.11.

Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
Cc: Mateusz Guzik <mguzik@redhat.com>
Cc: Petr Matousek <pmatouse@redhat.com>
Cc: Kent Overstreet <kmo@daterainc.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
fs/aio.c | 3 +++
1 file changed, 3 insertions(+)

--- a/fs/aio.c
+++ b/fs/aio.c
@@ -1063,6 +1063,9 @@ static long aio_read_events_ring(struct
if (head == tail)
goto out;

+ head %= ctx->nr_events;
+ tail %= ctx->nr_events;
+
while (ret < nr) {
long avail;
struct io_event *ev;



\
 
 \ /
  Last update: 2014-06-28 21:21    [W:0.558 / U:0.120 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site