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Add vhost-net use-after-free fix (rhbz 976789 980643)

This commit is contained in:
Josh Boyer 2013-07-05 09:01:24 -04:00
parent 8fb285bdac
commit 333a655d54
2 changed files with 83 additions and 0 deletions
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7
kernel.spec
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@ -794,6 +794,9 @@ Patch25055: ath3k-dont-use-stack-memory-for-DMA.patch
Patch25056: iwl3945-better-skb-management-in-rx-path.patch
Patch25057: iwl4965-better-skb-management-in-rx-path.patch
#rhbz 976789 980643
Patch25062: vhost-net-fix-use-after-free-in-vhost_net_flush.patch
# END OF PATCH DEFINITIONS
%endif
@ -1512,6 +1515,9 @@ ApplyPatch ath3k-dont-use-stack-memory-for-DMA.patch
ApplyPatch iwl3945-better-skb-management-in-rx-path.patch
ApplyPatch iwl4965-better-skb-management-in-rx-path.patch
#rhbz 976789 980643
ApplyPatch vhost-net-fix-use-after-free-in-vhost_net_flush.patch
# END OF PATCH APPLICATIONS
%endif
@ -2309,6 +2315,7 @@ fi
# || ||
%changelog
* Fri Jul 05 2013 Josh Boyer <jwboyer@redhat.com>
- Add vhost-net use-after-free fix (rhbz 976789 980643)
- Add fix for timer issue in bridge code (rhbz 980254)
* Wed Jul 03 2013 Josh Boyer <jwboyer@redhat.com>

76
vhost-net-fix-use-after-free-in-vhost_net_flush.patch Normal file
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@ -0,0 +1,76 @@
Date: Tue, 25 Jun 2013 17:29:46 +0300
From: "Michael S. Tsirkin" <mst@redhat.com>
To: linux-kernel@vger.kernel.org
Cc: "David S. Miller" <davem@davemloft.net>,
Asias He <asias@redhat.com>, Jason Wang <jasowang@redhat.com>,
kvm@vger.kernel.org, virtualization@lists.linux-foundation.org,
netdev@vger.kernel.org
Subject: [PATCHv2] vhost-net: fix use-after-free in vhost_net_flush
Message-ID: <20130625142946.GA17414@redhat.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
X-Scanned-By: MIMEDefang 2.67 on 10.5.11.11
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org
vhost_net_ubuf_put_and_wait has a confusing name:
it will actually also free it's argument.
Thus since commit 1280c27f8e29acf4af2da914e80ec27c3dbd5c01
"vhost-net: flush outstanding DMAs on memory change"
vhost_net_flush tries to use the argument after passing it
to vhost_net_ubuf_put_and_wait, this results
in use after free.
To fix, don't free the argument in vhost_net_ubuf_put_and_wait,
add an new API for callers that want to free ubufs.
Acked-by: Asias He <asias@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
Please review, and queue for 3.10 and stable.
Changes since v1:
- no functional change, tweaked the commit message
drivers/vhost/net.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 5c77d6a..534adb0 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -149,6 +149,11 @@ static void vhost_net_ubuf_put_and_wait(struct vhost_net_ubuf_ref *ubufs)
{
kref_put(&ubufs->kref, vhost_net_zerocopy_done_signal);
wait_event(ubufs->wait, !atomic_read(&ubufs->kref.refcount));
+}
+
+static void vhost_net_ubuf_put_wait_and_free(struct vhost_net_ubuf_ref *ubufs)
+{
+ vhost_net_ubuf_put_and_wait(ubufs);
kfree(ubufs);
}
@@ -1073,7 +1078,7 @@ static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd)
mutex_unlock(&vq->mutex);
if (oldubufs) {
- vhost_net_ubuf_put_and_wait(oldubufs);
+ vhost_net_ubuf_put_wait_and_free(oldubufs);
mutex_lock(&vq->mutex);
vhost_zerocopy_signal_used(n, vq);
mutex_unlock(&vq->mutex);
@@ -1091,7 +1096,7 @@ err_used:
vq->private_data = oldsock;
vhost_net_enable_vq(n, vq);
if (ubufs)
- vhost_net_ubuf_put_and_wait(ubufs);
+ vhost_net_ubuf_put_wait_and_free(ubufs);
err_ubufs:
fput(sock->file);
err_vq: