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

[Niklas Cassel]

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>
---
Currently, if doing NVME_IOCTL_IO_CMD on the controller char device,
if and only if there is a single namespace in the ctrl->namespaces list,
nvme_dev_user_cmd() will call nvme_user_cmd() with ns parameter set.
While it might be good that we validate the nsid even in this case,
perhaps we want to allow a nsid value in the passthru command to be
0x0 and/or the NSID broadcast value? (Only when NVME_IOCTL_IO_CMD was
done on the controller char device though.)

 drivers/nvme/host/core.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 40215a0246e4..e4591a4c68a8 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -1632,6 +1632,8 @@ 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)
+		return -EINVAL;
 
 	memset(&c, 0, sizeof(c));
 	c.common.opcode = cmd.opcode;
@@ -1676,6 +1678,8 @@ 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)
+		return -EINVAL;
 
 	memset(&c, 0, sizeof(c));
 	c.common.opcode = cmd.opcode;
-- 
2.30.2