Patch "drivers: hv: Turn off write permission on the hypercall page" has been added to the 4.9-stable tree

Patch "drivers: hv: Turn off write permission on the hypercall page" has been added to the 4.9-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    drivers: hv: Turn off write permission on the hypercall page

to the 4.9-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:
     drivers-hv-turn-off-write-permission-on-the-hypercall-page.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 372b1e91343e657a7cc5e2e2bcecd5140ac28119 Mon Sep 17 00:00:00 2001
From: "K. Y. Srinivasan" <kys@microsoft.com>
Date: Wed, 8 Feb 2017 18:30:56 -0700
Subject: drivers: hv: Turn off write permission on the hypercall page

From: K. Y. Srinivasan <kys@microsoft.com>

commit 372b1e91343e657a7cc5e2e2bcecd5140ac28119 upstream.

The hypercall page only needs to be executable but currently it is setup to
be writable as well. Fix the issue.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Acked-by: Kees Cook <keescook@chromium.org>
Reported-by: Stephen Hemminger <stephen@networkplumber.org>
Tested-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/hv/hv.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/hv/hv.c
+++ b/drivers/hv/hv.c
@@ -220,7 +220,7 @@ int hv_init(void)
 	/* See if the hypercall page is already set */
 	rdmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
 
-	virtaddr = __vmalloc(PAGE_SIZE, GFP_KERNEL, PAGE_KERNEL_EXEC);
+	virtaddr = __vmalloc(PAGE_SIZE, GFP_KERNEL, PAGE_KERNEL_RX);
 
 	if (!virtaddr)
 		goto cleanup;


Patches currently in stable-queue which might be from kys@microsoft.com are

queue-4.9/drivers-hv-turn-off-write-permission-on-the-hypercall-page.patch