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* [PATCH] sgi-xp: use designated initializers
@ 2016-12-17  1:01 Kees Cook
  2016-12-21 16:24 ` Robin Holt
  0 siblings, 1 reply; 6+ messages in thread
From: Kees Cook @ 2016-12-17  1:01 UTC (permalink / raw)
  To: linux-kernel; +Cc: Cliff Whickman, Robin Holt

Prepare to mark sensitive kernel structures for randomization by making
sure they're using designated initializers. These were identified during
allyesconfig builds of x86, arm, and arm64, with most initializer fixes
extracted from grsecurity.

Signed-off-by: Kees Cook <keescook@chromium.org>
---
 drivers/misc/sgi-xp/xp_main.c | 59 ++++++++++++++++++++++++++++---------------
 1 file changed, 39 insertions(+), 20 deletions(-)

diff --git a/drivers/misc/sgi-xp/xp_main.c b/drivers/misc/sgi-xp/xp_main.c
index 01be66d02ca8..bb47f9d9b68a 100644
--- a/drivers/misc/sgi-xp/xp_main.c
+++ b/drivers/misc/sgi-xp/xp_main.c
@@ -71,20 +71,44 @@ EXPORT_SYMBOL_GPL(xpc_registrations);
 /*
  * Initialize the XPC interface to indicate that XPC isn't loaded.
  */
-static enum xp_retval
-xpc_notloaded(void)
+static void xpc_notloaded_connect(int ch_number)
+{ }
+
+static void xpc_notloaded_disconnect(int ch_number)
+{ }
+
+static enum xp_retval xpc_notloaded_send(short partid, int ch_number,
+					 u32 flags, void *payload,
+					 u16 payload_size)
+{
+	return xpNotLoaded;
+}
+
+static enum xp_retval xpc_notloaded_send_notify(short partid, int ch_number,
+						u32 flags, void *payload,
+						u16 payload_size,
+						xpc_notify_func func,
+						void *key)
+{
+	return xpNotLoaded;
+}
+
+static void xpc_notloaded_received(short partid, int ch_number, void *payload)
+{ }
+
+static enum xp_retval xpc_notloaded_partid_to_nasids(short partid,
+						     void *nasid_mask)
 {
 	return xpNotLoaded;
 }
 
 struct xpc_interface xpc_interface = {
-	(void (*)(int))xpc_notloaded,
-	(void (*)(int))xpc_notloaded,
-	(enum xp_retval(*)(short, int, u32, void *, u16))xpc_notloaded,
-	(enum xp_retval(*)(short, int, u32, void *, u16, xpc_notify_func,
-			   void *))xpc_notloaded,
-	(void (*)(short, int, void *))xpc_notloaded,
-	(enum xp_retval(*)(short, void *))xpc_notloaded
+	.connect = xpc_notloaded_connect,
+	.disconnect = xpc_notloaded_disconnect,
+	.send = xpc_notloaded_send,
+	.send_notify = xpc_notloaded_send_notify,
+	.received = xpc_notloaded_received,
+	.partid_to_nasids = xpc_notloaded_partid_to_nasids
 };
 EXPORT_SYMBOL_GPL(xpc_interface);
 
@@ -115,17 +139,12 @@ EXPORT_SYMBOL_GPL(xpc_set_interface);
 void
 xpc_clear_interface(void)
 {
-	xpc_interface.connect = (void (*)(int))xpc_notloaded;
-	xpc_interface.disconnect = (void (*)(int))xpc_notloaded;
-	xpc_interface.send = (enum xp_retval(*)(short, int, u32, void *, u16))
-	    xpc_notloaded;
-	xpc_interface.send_notify = (enum xp_retval(*)(short, int, u32, void *,
-						       u16, xpc_notify_func,
-						       void *))xpc_notloaded;
-	xpc_interface.received = (void (*)(short, int, void *))
-	    xpc_notloaded;
-	xpc_interface.partid_to_nasids = (enum xp_retval(*)(short, void *))
-	    xpc_notloaded;
+	xpc_interface.connect = xpc_notloaded_connect;
+	xpc_interface.disconnect = xpc_notloaded_disconnect;
+	xpc_interface.send = xpc_notloaded_send;
+	xpc_interface.send_notify = xpc_notloaded_send_notify;
+	xpc_interface.received = xpc_notloaded_received;
+	xpc_interface.partid_to_nasids = xpc_notloaded_partid_to_nasids;
 }
 EXPORT_SYMBOL_GPL(xpc_clear_interface);
 
-- 
2.7.4


-- 
Kees Cook
Nexus Security

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH] sgi-xp: use designated initializers
  2016-12-17  1:01 [PATCH] sgi-xp: use designated initializers Kees Cook
@ 2016-12-21 16:24 ` Robin Holt
  2017-01-03 23:19   ` Kees Cook
  0 siblings, 1 reply; 6+ messages in thread
From: Robin Holt @ 2016-12-21 16:24 UTC (permalink / raw)
  To: Kees Cook; +Cc: LKML, Cliff Whickman

On Fri, Dec 16, 2016 at 7:01 PM, Kees Cook <keescook@chromium.org> wrote:
> Prepare to mark sensitive kernel structures for randomization by making
> sure they're using designated initializers. These were identified during
> allyesconfig builds of x86, arm, and arm64, with most initializer fixes
> extracted from grsecurity.

I guess I don't understand the context enough here to give you a
Signed-off-by.  Can you give us more background on this randomization?

>From what I see in the code here, I can see you are providing
equivalent functionality and I would give it a signed-off-by, but I am
not sure this randomization of which you speak is not going to cause
problems for XP, XPC, XPNET, and XPMEM (out of tree GPL kernel
module).

Robin

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH] sgi-xp: use designated initializers
  2016-12-21 16:24 ` Robin Holt
@ 2017-01-03 23:19   ` Kees Cook
  2017-03-29 20:48     ` Kees Cook
  0 siblings, 1 reply; 6+ messages in thread
From: Kees Cook @ 2017-01-03 23:19 UTC (permalink / raw)
  To: Robin Holt; +Cc: LKML, Cliff Whickman

On Wed, Dec 21, 2016 at 8:24 AM, Robin Holt <robinmholt@gmail.com> wrote:
> On Fri, Dec 16, 2016 at 7:01 PM, Kees Cook <keescook@chromium.org> wrote:
>> Prepare to mark sensitive kernel structures for randomization by making
>> sure they're using designated initializers. These were identified during
>> allyesconfig builds of x86, arm, and arm64, with most initializer fixes
>> extracted from grsecurity.
>
> I guess I don't understand the context enough here to give you a
> Signed-off-by.  Can you give us more background on this randomization?

Sure thing! The randomization is on the order of function pointers in
all-pointer structures (like struct xpc_interface). As long as the
memory containing the structure isn't shared externally, this
randomization should have no operational effect. The reason explicit
no-op functions were added was to avoid ugly casts, etc.

> From what I see in the code here, I can see you are providing
> equivalent functionality and I would give it a signed-off-by, but I am
> not sure this randomization of which you speak is not going to cause
> problems for XP, XPC, XPNET, and XPMEM (out of tree GPL kernel
> module).

Ah, hm, does this module share the structure without being built
against the kernel? (If built with the kernel, the randomization
plugin will keep things in the right order.)

-Kees

-- 
Kees Cook
Nexus Security

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH] sgi-xp: use designated initializers
  2017-01-03 23:19   ` Kees Cook
@ 2017-03-29 20:48     ` Kees Cook
  2017-05-06  7:16       ` Kees Cook
  0 siblings, 1 reply; 6+ messages in thread
From: Kees Cook @ 2017-03-29 20:48 UTC (permalink / raw)
  To: Robin Holt; +Cc: LKML, Cliff Whickman

On Tue, Jan 3, 2017 at 3:19 PM, Kees Cook <keescook@chromium.org> wrote:
> On Wed, Dec 21, 2016 at 8:24 AM, Robin Holt <robinmholt@gmail.com> wrote:
>> On Fri, Dec 16, 2016 at 7:01 PM, Kees Cook <keescook@chromium.org> wrote:
>>> Prepare to mark sensitive kernel structures for randomization by making
>>> sure they're using designated initializers. These were identified during
>>> allyesconfig builds of x86, arm, and arm64, with most initializer fixes
>>> extracted from grsecurity.
>>
>> I guess I don't understand the context enough here to give you a
>> Signed-off-by.  Can you give us more background on this randomization?
>
> Sure thing! The randomization is on the order of function pointers in
> all-pointer structures (like struct xpc_interface). As long as the
> memory containing the structure isn't shared externally, this
> randomization should have no operational effect. The reason explicit
> no-op functions were added was to avoid ugly casts, etc.

Friendly ping ... any chance this can land in -next soon?

>> From what I see in the code here, I can see you are providing
>> equivalent functionality and I would give it a signed-off-by, but I am
>> not sure this randomization of which you speak is not going to cause
>> problems for XP, XPC, XPNET, and XPMEM (out of tree GPL kernel
>> module).
>
> Ah, hm, does this module share the structure without being built
> against the kernel? (If built with the kernel, the randomization
> plugin will keep things in the right order.)

Regardless of your answer, this randomization can be turned off.
Switching to designated initializers here is mainly just a clean up.

Thanks!

-Kees

-- 
Kees Cook
Pixel Security

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH] sgi-xp: use designated initializers
  2017-03-29 20:48     ` Kees Cook
@ 2017-05-06  7:16       ` Kees Cook
  2017-05-08 17:32         ` Robin Holt
  0 siblings, 1 reply; 6+ messages in thread
From: Kees Cook @ 2017-05-06  7:16 UTC (permalink / raw)
  To: Robin Holt; +Cc: LKML, Cliff Whickman

On Wed, Mar 29, 2017 at 1:48 PM, Kees Cook <keescook@chromium.org> wrote:
> On Tue, Jan 3, 2017 at 3:19 PM, Kees Cook <keescook@chromium.org> wrote:
>> On Wed, Dec 21, 2016 at 8:24 AM, Robin Holt <robinmholt@gmail.com> wrote:
>>> On Fri, Dec 16, 2016 at 7:01 PM, Kees Cook <keescook@chromium.org> wrote:
>>>> Prepare to mark sensitive kernel structures for randomization by making
>>>> sure they're using designated initializers. These were identified during
>>>> allyesconfig builds of x86, arm, and arm64, with most initializer fixes
>>>> extracted from grsecurity.
>>>
>>> I guess I don't understand the context enough here to give you a
>>> Signed-off-by.  Can you give us more background on this randomization?
>>
>> Sure thing! The randomization is on the order of function pointers in
>> all-pointer structures (like struct xpc_interface). As long as the
>> memory containing the structure isn't shared externally, this
>> randomization should have no operational effect. The reason explicit
>> no-op functions were added was to avoid ugly casts, etc.
>
> Friendly ping ... any chance this can land in -next soon?
>
>>> From what I see in the code here, I can see you are providing
>>> equivalent functionality and I would give it a signed-off-by, but I am
>>> not sure this randomization of which you speak is not going to cause
>>> problems for XP, XPC, XPNET, and XPMEM (out of tree GPL kernel
>>> module).
>>
>> Ah, hm, does this module share the structure without being built
>> against the kernel? (If built with the kernel, the randomization
>> plugin will keep things in the right order.)
>
> Regardless of your answer, this randomization can be turned off.
> Switching to designated initializers here is mainly just a clean up.

Any thoughts on this? I'd love to get this landed, and I'm happy to
carry the patch myself, if it helps. Anyone able to Ack?

Thanks!

-Kees

-- 
Kees Cook
Pixel Security

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH] sgi-xp: use designated initializers
  2017-05-06  7:16       ` Kees Cook
@ 2017-05-08 17:32         ` Robin Holt
  0 siblings, 0 replies; 6+ messages in thread
From: Robin Holt @ 2017-05-08 17:32 UTC (permalink / raw)
  To: Kees Cook; +Cc: LKML, Cliff Whickman

Acked-by: Robin Holt <robinmholt@gmail.com>

Robin Holt

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2017-05-08 17:32 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2016-12-17  1:01 [PATCH] sgi-xp: use designated initializers Kees Cook
2016-12-21 16:24 ` Robin Holt
2017-01-03 23:19   ` Kees Cook
2017-03-29 20:48     ` Kees Cook
2017-05-06  7:16       ` Kees Cook
2017-05-08 17:32         ` Robin Holt

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