From 0516ffd88fa0d006ee80389ce14a9ca5ae45e845 Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Thu, 19 Jan 2017 10:43:53 +0000 Subject: vhost/vsock: handle vhost_vq_init_access() error Propagate the error when vhost_vq_init_access() fails and set vq->private_data to NULL. Signed-off-by: Stefan Hajnoczi Signed-off-by: Michael S. Tsirkin --- drivers/vhost/vsock.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) (limited to 'drivers/vhost') diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c index bbbf588540ed..ce5e63d2c66a 100644 --- a/drivers/vhost/vsock.c +++ b/drivers/vhost/vsock.c @@ -373,6 +373,7 @@ static void vhost_vsock_handle_rx_kick(struct vhost_work *work) static int vhost_vsock_start(struct vhost_vsock *vsock) { + struct vhost_virtqueue *vq; size_t i; int ret; @@ -383,19 +384,20 @@ static int vhost_vsock_start(struct vhost_vsock *vsock) goto err; for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) { - struct vhost_virtqueue *vq = &vsock->vqs[i]; + vq = &vsock->vqs[i]; mutex_lock(&vq->mutex); if (!vhost_vq_access_ok(vq)) { ret = -EFAULT; - mutex_unlock(&vq->mutex); goto err_vq; } if (!vq->private_data) { vq->private_data = vsock; - vhost_vq_init_access(vq); + ret = vhost_vq_init_access(vq); + if (ret) + goto err_vq; } mutex_unlock(&vq->mutex); @@ -405,8 +407,11 @@ static int vhost_vsock_start(struct vhost_vsock *vsock) return 0; err_vq: + vq->private_data = NULL; + mutex_unlock(&vq->mutex); + for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) { - struct vhost_virtqueue *vq = &vsock->vqs[i]; + vq = &vsock->vqs[i]; mutex_lock(&vq->mutex); vq->private_data = NULL; -- cgit v1.2.3 From cda8bba0f99d25d2061c531113c14fa41effc3ae Mon Sep 17 00:00:00 2001 From: Halil Pasic Date: Mon, 30 Jan 2017 11:09:36 +0100 Subject: vhost: fix initialization for vq->is_le Currently, under certain circumstances vhost_init_is_le does just a part of the initialization job, and depends on vhost_reset_is_le being called too. For this reason vhost_vq_init_access used to call vhost_reset_is_le when vq->private_data is NULL. This is not only counter intuitive, but also real a problem because it breaks vhost_net. The bug was introduced to vhost_net with commit 2751c9882b94 ("vhost: cross-endian support for legacy devices"). The symptom is corruption of the vq's used.idx field (virtio) after VHOST_NET_SET_BACKEND was issued as a part of the vhost shutdown on a vq with pending descriptors. Let us make sure the outcome of vhost_init_is_le never depend on the state it is actually supposed to initialize, and fix virtio_net by removing the reset from vhost_vq_init_access. With the above, there is no reason for vhost_reset_is_le to do just half of the job. Let us make vhost_reset_is_le reinitialize is_le. Signed-off-by: Halil Pasic Reported-by: Michael A. Tebolt Reported-by: Dr. David Alan Gilbert Fixes: commit 2751c9882b94 ("vhost: cross-endian support for legacy devices") Cc: Signed-off-by: Michael S. Tsirkin Reviewed-by: Greg Kurz Tested-by: Michael A. Tebolt --- drivers/vhost/vhost.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) (limited to 'drivers/vhost') diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index d6432603880c..8f99fe08de02 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -130,14 +130,14 @@ static long vhost_get_vring_endian(struct vhost_virtqueue *vq, u32 idx, static void vhost_init_is_le(struct vhost_virtqueue *vq) { - if (vhost_has_feature(vq, VIRTIO_F_VERSION_1)) - vq->is_le = true; + vq->is_le = vhost_has_feature(vq, VIRTIO_F_VERSION_1) + || virtio_legacy_is_little_endian(); } #endif /* CONFIG_VHOST_CROSS_ENDIAN_LEGACY */ static void vhost_reset_is_le(struct vhost_virtqueue *vq) { - vq->is_le = virtio_legacy_is_little_endian(); + vhost_init_is_le(vq); } struct vhost_flush_struct { @@ -1714,10 +1714,8 @@ int vhost_vq_init_access(struct vhost_virtqueue *vq) int r; bool is_le = vq->is_le; - if (!vq->private_data) { - vhost_reset_is_le(vq); + if (!vq->private_data) return 0; - } vhost_init_is_le(vq); -- cgit v1.2.3