blob: 831a6a85fe408248fe644a2cd60a19bbe01a352e (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
|
Bugzilla: 1112975
Upstream-status: 3.16 and CC'd to stable
From edfbbf388f293d70bf4b7c0bc38774d05e6f711a Mon Sep 17 00:00:00 2001
From: Benjamin LaHaise <bcrl@kvack.org>
Date: Tue, 24 Jun 2014 13:32:51 -0400
Subject: [PATCH] aio: fix kernel memory disclosure in io_getevents()
introduced in v3.10
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>
Cc: stable@vger.kernel.org
---
fs/aio.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/fs/aio.c b/fs/aio.c
index 6a9c7e489adf..955947ef3e02 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -1063,6 +1063,9 @@ static long aio_read_events_ring(struct kioctx *ctx,
if (head == tail)
goto out;
+ head %= ctx->nr_events;
+ tail %= ctx->nr_events;
+
while (ret < nr) {
long avail;
struct io_event *ev;
--
1.9.3
|
