From 1bad6c2d7302cceed2eaf4896320f9fe7421772e Mon Sep 17 00:00:00 2001 From: Kai Kang Date: Wed, 26 Oct 2016 17:54:49 +0800 Subject: qemu: supplementary fix of CVE-2016-5403 It is reported in qemu community that VM always exits with: | 2016-10-17T07:33:40.393592Z qemu-kvm: Virtqueue size exceede when VM is suspend and resume. Solution from the maintainer of virtio is to merge following 3 commits: http://git.qemu.org/?p=qemu.git;a=commit;h=bccdef6 http://git.qemu.org/?p=qemu.git;a=commit;h=58a83c6 http://git.qemu.org/?p=qemu.git;a=commit;h=4b7f91e The first 2 commits have been merged in qemu 2.7.0. Then apply the third one. (From OE-Core rev: db5b9254fbbc30e50b50c7c8cd1f04dcc965cd52) (From OE-Core rev: 7fa650825957257e6f99d44907c65fd46875125c) Signed-off-by: Kai Kang Signed-off-by: Ross Burton Signed-off-by: Richard Purdie Signed-off-by: Armin Kuster Signed-off-by: Richard Purdie --- ...0001-virtio-zero-vq-inuse-in-virtio_reset.patch | 57 ++++++++++++++++++++++ meta/recipes-devtools/qemu/qemu_2.7.0.bb | 1 + 2 files changed, 58 insertions(+) create mode 100644 meta/recipes-devtools/qemu/qemu/0001-virtio-zero-vq-inuse-in-virtio_reset.patch (limited to 'meta/recipes-devtools') diff --git a/meta/recipes-devtools/qemu/qemu/0001-virtio-zero-vq-inuse-in-virtio_reset.patch b/meta/recipes-devtools/qemu/qemu/0001-virtio-zero-vq-inuse-in-virtio_reset.patch new file mode 100644 index 0000000000..86955d0437 --- /dev/null +++ b/meta/recipes-devtools/qemu/qemu/0001-virtio-zero-vq-inuse-in-virtio_reset.patch @@ -0,0 +1,57 @@ +Upstream-Status: Backport + +Supplementary fix of CVE-2016-5403 which is backported from: + +http://git.qemu.org/?p=qemu.git;a=commit;h=4b7f91e + +Signed-off-by: Kai Kang +--- +From 4b7f91ed0270a371e1933efa21ba600b6da23ab9 Mon Sep 17 00:00:00 2001 +From: Stefan Hajnoczi +Date: Wed, 7 Sep 2016 11:51:25 -0400 +Subject: [PATCH] virtio: zero vq->inuse in virtio_reset() + +vq->inuse must be zeroed upon device reset like most other virtqueue +fields. + +In theory, virtio_reset() just needs assert(vq->inuse == 0) since +devices must clean up in-flight requests during reset (requests cannot +not be leaked!). + +In practice, it is difficult to achieve vq->inuse == 0 across reset +because balloon, blk, 9p, etc implement various different strategies for +cleaning up requests. Most devices call g_free(elem) directly without +telling virtio.c that the VirtQueueElement is cleaned up. Therefore +vq->inuse is not decremented during reset. + +This patch zeroes vq->inuse and trusts that devices are not leaking +VirtQueueElements across reset. + +I will send a follow-up series that refactors request life-cycle across +all devices and converts vq->inuse = 0 into assert(vq->inuse == 0) but +this more invasive approach is not appropriate for stable trees. + +Signed-off-by: Stefan Hajnoczi +Cc: qemu-stable +Reviewed-by: Michael S. Tsirkin +Signed-off-by: Michael S. Tsirkin +Reviewed-by: Ladi Prosek +--- + hw/virtio/virtio.c | 1 + + 1 file changed, 1 insertion(+) + +diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c +index 74c085c..e8a13a5 100644 +--- a/hw/virtio/virtio.c ++++ b/hw/virtio/virtio.c +@@ -822,6 +822,7 @@ void virtio_reset(void *opaque) + vdev->vq[i].signalled_used_valid = false; + vdev->vq[i].notification = true; + vdev->vq[i].vring.num = vdev->vq[i].vring.num_default; ++ vdev->vq[i].inuse = 0; + } + } + +-- +2.9.3 + diff --git a/meta/recipes-devtools/qemu/qemu_2.7.0.bb b/meta/recipes-devtools/qemu/qemu_2.7.0.bb index 619b8ed449..90e4eecb10 100644 --- a/meta/recipes-devtools/qemu/qemu_2.7.0.bb +++ b/meta/recipes-devtools/qemu/qemu_2.7.0.bb @@ -9,6 +9,7 @@ SRC_URI += "file://configure-fix-Darwin-target-detection.patch \ file://no-valgrind.patch \ file://pathlimit.patch \ file://qemu-2.5.0-cflags.patch \ + file://0001-virtio-zero-vq-inuse-in-virtio_reset.patch \ " SRC_URI_prepend = "http://wiki.qemu-project.org/download/${BP}.tar.bz2" -- cgit v1.2.3-54-g00ecf