nvme: fixes for NVME_IOCTL_IO_CMD on the char device

Make sure we synchronize access to the namespaces list and grab a reference
to the namespace before doing I/O.  Make sure to reject the ioctl if multiple
namespaces are present as it's entirely unsafe, and warn when using it even
with a single namespace.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Acked-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
This commit is contained in:
Christoph Hellwig 2015-12-24 15:27:01 +01:00 committed by Jens Axboe
parent 69d3b8ac15
commit bfd8947194

View file

@ -922,21 +922,50 @@ static int nvme_dev_release(struct inode *inode, struct file *file)
return 0;
}
static int nvme_dev_user_cmd(struct nvme_ctrl *ctrl, void __user *argp)
{
struct nvme_ns *ns;
int ret;
mutex_lock(&ctrl->namespaces_mutex);
if (list_empty(&ctrl->namespaces)) {
ret = -ENOTTY;
goto out_unlock;
}
ns = list_first_entry(&ctrl->namespaces, struct nvme_ns, list);
if (ns != list_last_entry(&ctrl->namespaces, struct nvme_ns, list)) {
dev_warn(ctrl->dev,
"NVME_IOCTL_IO_CMD not supported when multiple namespaces present!\n");
ret = -EINVAL;
goto out_unlock;
}
dev_warn(ctrl->dev,
"using deprecated NVME_IOCTL_IO_CMD ioctl on the char device!\n");
kref_get(&ns->kref);
mutex_unlock(&ctrl->namespaces_mutex);
ret = nvme_user_cmd(ctrl, ns, argp);
nvme_put_ns(ns);
return ret;
out_unlock:
mutex_unlock(&ctrl->namespaces_mutex);
return ret;
}
static long nvme_dev_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
struct nvme_ctrl *ctrl = file->private_data;
void __user *argp = (void __user *)arg;
struct nvme_ns *ns;
switch (cmd) {
case NVME_IOCTL_ADMIN_CMD:
return nvme_user_cmd(ctrl, NULL, argp);
case NVME_IOCTL_IO_CMD:
if (list_empty(&ctrl->namespaces))
return -ENOTTY;
ns = list_first_entry(&ctrl->namespaces, struct nvme_ns, list);
return nvme_user_cmd(ctrl, ns, argp);
return nvme_dev_user_cmd(ctrl, argp);
case NVME_IOCTL_RESET:
dev_warn(ctrl->dev, "resetting controller\n");
return ctrl->ops->reset_ctrl(ctrl);