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

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@wdc.com>
Reviewed-by: Javier González <javier@javigon.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Kanchan Joshi <joshi.k@samsung.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

drivers/nvme/host/core.c

@@ -1632,6 +1632,12 @@ 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;
@@ -1676,6 +1682,12 @@ 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;