@@ -218,6 +218,40 @@ static bool cxl_mem_raw_command_allowed(u16 opcode)
return true;
}
+/**
+ * cxl_payload_from_user_allowed() - Check contents of in_payload.
+ * @opcode: The mailbox command opcode.
+ * @payload_in: Pointer to the input payload passed in from user space.
+ *
+ * Return:
+ * * true - payload_in passes check for @opcode.
+ * * false - payload_in contains invalid or unsupported values.
+ *
+ * The driver may inspect payload contents before sending a mailbox
+ * command from user space to the device. The intent is to reject
+ * commands with input payloads that are known to be unsafe. This
+ * check is not intended to replace the users careful selection of
+ * mailbox command parameters and makes no guarantee that the user
+ * command will succeed, nor that it is appropriate.
+ *
+ * The specific checks are determined by the opcode.
+ */
+static bool cxl_payload_from_user_allowed(u16 opcode, void *payload_in)
+{
+ switch (opcode) {
+ case CXL_MBOX_OP_SET_PARTITION_INFO: {
+ struct cxl_mbox_set_partition_info *pi = payload_in;
+
+ if (pi->flags && CXL_SET_PARTITION_IMMEDIATE_FLAG)
+ return false;
+ break;
+ }
+ default:
+ break;
+ }
+ return true;
+}
+
static int cxl_mbox_cmd_ctor(struct cxl_mbox_cmd *mbox,
struct cxl_dev_state *cxlds, u16 opcode,
size_t in_size, size_t out_size, u64 in_payload)
@@ -232,6 +266,13 @@ static int cxl_mbox_cmd_ctor(struct cxl_mbox_cmd *mbox,
in_size);
if (!mbox->payload_in)
return PTR_ERR(mbox->payload_in);
+
+ if (!cxl_payload_from_user_allowed(opcode, mbox->payload_in)) {
+ dev_dbg(cxlds->dev, "%s: input payload not allowed\n",
+ cxl_mem_opcode_to_name(opcode));
+ kvfree(mbox->payload_in);
+ return -EBUSY;
+ }
}
/* Prepare to handle a full payload for variable sized output */
@@ -264,6 +264,13 @@ struct cxl_mbox_set_lsa {
u8 data[];
} __packed;
+struct cxl_mbox_set_partition_info {
+ __le64 volatile_capacity;
+ u8 flags;
+} __packed;
+
+#define CXL_SET_PARTITION_IMMEDIATE_FLAG BIT(0)
+
/**
* struct cxl_mem_command - Driver representation of a memory device command
* @info: Command information as it exists for the UAPI