On Mon, Mar 07, 2022 at 07:17:57PM +0000, Lee Jones wrote:
vhost_vsock_handle_tx_kick() already holds the mutex during its call to vhost_get_vq_desc(). All we have to do here is take the same lock during virtqueue clean-up and we mitigate the reported issues.
Pls just basically copy the code comment here. this is just confuses.
Also WARN() as a precautionary measure. The purpose of this is to capture possible future race conditions which may pop up over time.
Link: https://syzkaller.appspot.com/bug?extid=279432d30d825e63ba00
And this is a bug we already fixed, right?
Cc: stable@vger.kernel.org Reported-by: syzbot+adc3cb32385586bec859@syzkaller.appspotmail.com
not really applicable anymore ...
Signed-off-by: Lee Jones lee.jones@linaro.org
drivers/vhost/vhost.c | 10 ++++++++++ 1 file changed, 10 insertions(+)
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index 59edb5a1ffe28..ef7e371e3e649 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -693,6 +693,15 @@ void vhost_dev_cleanup(struct vhost_dev *dev) int i; for (i = 0; i < dev->nvqs; ++i) {
/* No workers should run here by design. However, races have* previously occurred where drivers have been unable to flush* all work properly prior to clean-up. Without a successful* flush the guest will malfunction, but avoiding host memory* corruption in those cases does seem preferable.*/WARN_ON(mutex_is_locked(&dev->vqs[i]->mutex));mutex_lock(&dev->vqs[i]->mutex);@@ -700,6 +709,7 @@ void vhost_dev_cleanup(struct vhost_dev *dev) if (dev->vqs[i]->call_ctx.ctx) eventfd_ctx_put(dev->vqs[i]->call_ctx.ctx); vhost_vq_reset(dev, dev->vqs[i]);
mutex_unlock(&dev->vqs[i]->mutex);-- 2.35.1.616.g0bdcbb4464-goog