diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c
index b8ca6dff37b5..086268f1dd6c 100644
--- a/drivers/cxl/mem.c
+++ b/drivers/cxl/mem.c
@@ -119,6 +119,8 @@ static const uuid_t log_uuid[] = {
 				 0x07, 0x19, 0x40, 0x3d, 0x86)
 };
 
+static int validate_log_uuid(void __user *payload, size_t size);
+
 /**
  * struct cxl_mem_command - Driver representation of a memory device command
  * @info: Command information as it exists for the UAPI
@@ -132,6 +134,10 @@ static const uuid_t log_uuid[] = {
  *  * %CXL_CMD_INTERNAL_FLAG_PSEUDO: This is a pseudo command which doesn't have
  *    a direct mapping to hardware. They are implicitly always enabled.
  *
+ * @validate_payload: A function called after the command is validated but
+ * before it's sent to the hardware. The primary purpose is to validate, or
+ * fixup the actual payload.
+ *
  * The cxl_mem_command is the driver's internal representation of commands that
  * are supported by the driver. Some of these commands may not be supported by
  * the hardware. The driver will use @info to validate the fields passed in by
@@ -147,9 +153,11 @@ struct cxl_mem_command {
 #define CXL_CMD_INTERNAL_FLAG_HIDDEN BIT(0)
 #define CXL_CMD_INTERNAL_FLAG_MANDATORY BIT(1)
 #define CXL_CMD_INTERNAL_FLAG_PSEUDO BIT(2)
+
+	int (*validate_payload)(void __user *payload, size_t size);
 };
 
-#define CXL_CMD(_id, _flags, sin, sout, f)                                     \
+#define CXL_CMD_VALIDATE(_id, _flags, sin, sout, f, v)                         \
 	[CXL_MEM_COMMAND_ID_##_id] = {                                         \
 	.info =	{                                                              \
 			.id = CXL_MEM_COMMAND_ID_##_id,                        \
@@ -159,8 +167,12 @@ struct cxl_mem_command {
 		},                                                             \
 	.flags = CXL_CMD_INTERNAL_FLAG_##f,                                    \
 	.opcode = CXL_MBOX_OP_##_id,                                           \
+	.validate_payload = v,                                                 \
 	}
 
+#define CXL_CMD(_id, _flags, sin, sout, f)                                     \
+	CXL_CMD_VALIDATE(_id, _flags, sin, sout, f, NULL)
+
 /*
  * This table defines the supported mailbox commands for the driver. This table
  * is made up of a UAPI structure. Non-negative values as parameters in the
@@ -176,6 +188,8 @@ static struct cxl_mem_command mem_commands[] = {
 	CXL_CMD(GET_PARTITION_INFO, NONE, 0, 0x20, NONE),
 	CXL_CMD(GET_LSA, NONE, 0x8, ~0, MANDATORY),
 	CXL_CMD(GET_HEALTH_INFO, NONE, 0, 0x12, MANDATORY),
+	CXL_CMD_VALIDATE(GET_LOG, MUTEX, 0x18, ~0, MANDATORY,
+			 validate_log_uuid),
 };
 
 /*
@@ -563,6 +577,13 @@ static int handle_mailbox_cmd_from_user(struct cxl_memdev *cxlmd,
 			kvzalloc(cxlm->mbox.payload_size, GFP_KERNEL);
 
 	if (cmd->info.size_in) {
+		if (cmd->validate_payload) {
+			rc = cmd->validate_payload(u64_to_user_ptr(in_payload),
+						   cmd->info.size_in);
+			if (rc)
+				goto out;
+		}
+
 		mbox_cmd.payload_in = kvzalloc(cmd->info.size_in, GFP_KERNEL);
 		if (!mbox_cmd.payload_in) {
 			rc = -ENOMEM;
@@ -1205,6 +1226,25 @@ struct cxl_mbox_get_log {
 	__le32 length;
 } __packed;
 
+static int validate_log_uuid(void __user *input, size_t size)
+{
+	struct cxl_mbox_get_log __user *get_log = input;
+	uuid_t payload_uuid;
+
+	if (copy_from_user(&payload_uuid, &get_log->uuid, sizeof(uuid_t)))
+		return -EFAULT;
+
+	/* All unspec'd logs shall taint */
+	if (uuid_equal(&payload_uuid, &log_uuid[CEL_UUID]))
+		return 0;
+	if (uuid_equal(&payload_uuid, &log_uuid[DEBUG_UUID]))
+		return 0;
+
+	add_taint(TAINT_RAW_PASSTHROUGH, LOCKDEP_STILL_OK);
+
+	return 0;
+}
+
 static int cxl_xfer_log(struct cxl_mem *cxlm, uuid_t *uuid, u32 size, u8 *out)
 {
 	u32 remaining = size;
diff --git a/include/uapi/linux/cxl_mem.h b/include/uapi/linux/cxl_mem.h
index 766c231d6150..7cdc7f7ce7ec 100644
--- a/include/uapi/linux/cxl_mem.h
+++ b/include/uapi/linux/cxl_mem.h
@@ -39,6 +39,7 @@ extern "C" {
 	___C(GET_PARTITION_INFO, "Get Partition Information"),            \
 	___C(GET_LSA, "Get Label Storage Area"),                          \
 	___C(GET_HEALTH_INFO, "Get Health Info"),                         \
+	___C(GET_LOG, "Get Log"),                                         \
 	___C(MAX, "Last command")
 
 #define ___C(a, b) CXL_MEM_COMMAND_ID_##a
