[3.16.y-ckt stable] Patch "virtio: fix memory leak of virtio ida cache layers" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    virtio: fix memory leak of virtio ida cache layers

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt23.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

---8<------------------------------------------------------------

>From 1962eb806c080987c1631c977c0bfe77f0d0063a Mon Sep 17 00:00:00 2001
From: Suman Anna <s-anna at ti.com>
Date: Wed, 16 Sep 2015 19:29:17 -0500
Subject: virtio: fix memory leak of virtio ida cache layers

commit c13f99b7e945dad5273a8b7ee230f4d1f22d3354 upstream.

The virtio core uses a static ida named virtio_index_ida for
assigning index numbers to virtio devices during registration.
The ida core may allocate some internal idr cache layers and
an ida bitmap upon any ida allocation, and all these layers are
truely freed only upon the ida destruction. The virtio_index_ida
is not destroyed at present, leading to a memory leak when using
the virtio core as a module and atleast one virtio device is
registered and unregistered.

Fix this by invoking ida_destroy() in the virtio core module
exit.

Signed-off-by: Suman Anna <s-anna at ti.com>
Signed-off-by: Michael S. Tsirkin <mst at redhat.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/virtio/virtio.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
index fed0ce198ae3..64eba4f51f71 100644
--- a/drivers/virtio/virtio.c
+++ b/drivers/virtio/virtio.c
@@ -249,6 +249,7 @@ static int virtio_init(void)
 static void __exit virtio_exit(void)
 {
 	bus_unregister(&virtio_bus);
+	ida_destroy(&virtio_index_ida);
 }
 core_initcall(virtio_init);
 module_exit(virtio_exit);