Subject: + virtio_balloon-leak_balloon-only-tell-host-if-we-got-pages-deflated.patch added to -mm tree
To: lcapitulino@xxxxxxxxxx,aquini@xxxxxxxxxx,rusty@xxxxxxxxxxxxxxx
From: akpm@xxxxxxxxxxxxxxxxxxxx
Date: Mon, 17 Jun 2013 15:27:02 -0700
The patch titled
Subject: virtio_balloon: leak_balloon(): only tell host if we got pages deflated
has been added to the -mm tree. Its filename is
virtio_balloon-leak_balloon-only-tell-host-if-we-got-pages-deflated.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Luiz Capitulino <lcapitulino@xxxxxxxxxx>
Subject: virtio_balloon: leak_balloon(): only tell host if we got pages deflated
balloon_page_dequeue() can return NULL. If it does for the first page
being freed then leak_balloon() will create a scatter list with len=0.
Which in turn seems to generate an invalid virtio request.
I didn't get this in practice, I found it by code review. On the other
hand, such an invalid virtio request will cause errors in QEMU and
fill_balloon() also performs the same check implemented by this commit.
Signed-off-by: Luiz Capitulino <lcapitulino@xxxxxxxxxx>
Acked-by: Rafael Aquini <aquini@xxxxxxxxxx>
Cc: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/virtio/virtio_balloon.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff -puN drivers/virtio/virtio_balloon.c~virtio_balloon-leak_balloon-only-tell-host-if-we-got-pages-deflated drivers/virtio/virtio_balloon.c
--- a/drivers/virtio/virtio_balloon.c~virtio_balloon-leak_balloon-only-tell-host-if-we-got-pages-deflated
+++ a/drivers/virtio/virtio_balloon.c
@@ -191,7 +191,8 @@ static void leak_balloon(struct virtio_b
* virtio_has_feature(vdev, VIRTIO_BALLOON_F_MUST_TELL_HOST);
* is true, we *have* to do it in this order
*/
- tell_host(vb, vb->deflate_vq);
+ if (vb->num_pfns != 0)
+ tell_host(vb, vb->deflate_vq);
mutex_unlock(&vb->balloon_lock);
release_pages_by_pfn(vb->pfns, vb->num_pfns);
}
_
Patches currently in -mm which might be from lcapitulino@xxxxxxxxxx are
virtio_balloon-leak_balloon-only-tell-host-if-we-got-pages-deflated.patch
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
