nvme: disallow passthru cmd from targeting a nsid != nsid of the block dev

[javier at javigon.com]

On 26.03.2021 19:48, Niklas Cassel wrote:
>From: Niklas Cassel <niklas.cassel at wdc.com>
>
>When a passthru command targets a specific namespace, the ns parameter to
>nvme_user_cmd()/nvme_user_cmd64() is set. However, there is currently no
>validation that the nsid specified in the passthru command targets the
>namespace/nsid represented by the block device that the ioctl was
>performed on.
>
>Add a check that validates that the nsid in the passthru command matches
>that of the supplied namespace.
>
>Signed-off-by: Niklas Cassel <niklas.cassel at wdc.com>
>---
>Changes since v1:
>-Added error print.
>
> drivers/nvme/host/core.c | 12 ++++++++++++
> 1 file changed, 12 insertions(+)
>
>diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
>index f13eb4ded95f..a50352ea3f7b 100644
>--- a/drivers/nvme/host/core.c
>+++ b/drivers/nvme/host/core.c
>@@ -1599,6 +1599,12 @@ static int nvme_user_cmd(struct nvme_ctrl *ctrl, struct nvme_ns *ns,
> 		return -EFAULT;
> 	if (cmd.flags)
> 		return -EINVAL;
>+	if (ns && cmd.nsid != ns->head->ns_id) {
>+		dev_err(ctrl->device,
>+			"%s: nsid (%u) in cmd does not match nsid (%u) of namespace\n",
>+			current->comm, cmd.nsid, ns->head->ns_id);
>+		return -EINVAL;
>+	}
>
> 	memset(&c, 0, sizeof(c));
> 	c.common.opcode = cmd.opcode;
>@@ -1643,6 +1649,12 @@ static int nvme_user_cmd64(struct nvme_ctrl *ctrl, struct nvme_ns *ns,
> 		return -EFAULT;
> 	if (cmd.flags)
> 		return -EINVAL;
>+	if (ns && cmd.nsid != ns->head->ns_id) {
>+		dev_err(ctrl->device,
>+			"%s: nsid (%u) in cmd does not match nsid (%u) of namespace\n",
>+			current->comm, cmd.nsid, ns->head->ns_id);
>+		return -EINVAL;
>+	}
>
> 	memset(&c, 0, sizeof(c));
> 	c.common.opcode = cmd.opcode;
>-- 
>2.30.2

Looks good to me

Reviewed-by: Javier González <javier at javigon.com>