This is a note to let you know that I've just added the patch titled
agp: fix arbitrary kernel memory writes
to the 2.6.38-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:
agp-fix-arbitrary-kernel-memory-writes.patch
and it can be found in the queue-2.6.38 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From 194b3da873fd334ef183806db751473512af29ce Mon Sep 17 00:00:00 2001
From: Vasiliy Kulikov <[email protected]>
Date: Thu, 14 Apr 2011 20:55:16 +0400
Subject: agp: fix arbitrary kernel memory writes
From: Vasiliy Kulikov <[email protected]>
commit 194b3da873fd334ef183806db751473512af29ce upstream.
pg_start is copied from userspace on AGPIOC_BIND and AGPIOC_UNBIND ioctl
cmds of agp_ioctl() and passed to agpioc_bind_wrap(). As said in the
comment, (pg_start + mem->page_count) may wrap in case of AGPIOC_BIND,
and it is not checked at all in case of AGPIOC_UNBIND. As a result, user
with sufficient privileges (usually "video" group) may generate either
local DoS or privilege escalation.
Signed-off-by: Vasiliy Kulikov <[email protected]>
Signed-off-by: Dave Airlie <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
drivers/char/agp/generic.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)
--- a/drivers/char/agp/generic.c
+++ b/drivers/char/agp/generic.c
@@ -1089,8 +1089,8 @@ int agp_generic_insert_memory(struct agp
return -EINVAL;
}
- /* AK: could wrap */
- if ((pg_start + mem->page_count) > num_entries)
+ if (((pg_start + mem->page_count) > num_entries) ||
+ ((pg_start + mem->page_count) < pg_start))
return -EINVAL;
j = pg_start;
@@ -1124,7 +1124,7 @@ int agp_generic_remove_memory(struct agp
{
size_t i;
struct agp_bridge_data *bridge;
- int mask_type;
+ int mask_type, num_entries;
bridge = mem->bridge;
if (!bridge)
@@ -1136,6 +1136,11 @@ int agp_generic_remove_memory(struct agp
if (type != mem->type)
return -EINVAL;
+ num_entries = agp_num_entries();
+ if (((pg_start + mem->page_count) > num_entries) ||
+ ((pg_start + mem->page_count) < pg_start))
+ return -EINVAL;
+
mask_type = bridge->driver->agp_type_to_mask_type(bridge, type);
if (mask_type != 0) {
/* The generic routines know nothing of memory types */
Patches currently in stable-queue which might be from [email protected] are
queue-2.6.38/agp-fix-arbitrary-kernel-memory-writes.patch
queue-2.6.38/agp-fix-oom-and-buffer-overflow.patch
_______________________________________________
stable mailing list
[email protected]
http://linux.kernel.org/mailman/listinfo/stable
