diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c
index 6dfc8ff0aefb..593db737e7a4 100644
--- a/drivers/cxl/mem.c
+++ b/drivers/cxl/mem.c
@@ -94,7 +94,7 @@ static struct {
 } command_names[] = { CMDS };
 #undef C
 
-#define CXL_CMD(_id, _flags, sin, sout, f)                                     \
+#define CXL_CMD_VALIDATE(_id, _flags, sin, sout, f, v)                         \
 	[CXL_MEM_COMMAND_ID_##_id] = {                                         \
 		{                                                              \
 			.id = CXL_MEM_COMMAND_ID_##_id,                        \
@@ -104,8 +104,12 @@ static struct {
 		},                                                             \
 			.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)
+
 enum {
 	CEL_UUID,
 	DEBUG_UUID
@@ -116,6 +120,8 @@ static const uuid_t log_uuid[] = {
 	UUID_INIT(0xe1819d9, 0x11a9, 0x400c, 0x81, 0x1f, 0xd6, 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
@@ -129,6 +135,10 @@ 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
@@ -144,6 +154,8 @@ 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);
 };
 
 /*
@@ -157,6 +169,8 @@ static struct cxl_mem_command mem_commands[] = {
 	CXL_CMD(IDENTIFY, NONE, 0, 0x43, MANDATORY),
 	CXL_CMD(RAW, NONE, ~0, ~0, PSEUDO),
 	CXL_CMD(GET_SUPPORTED_LOGS, NONE, 0, ~0, MANDATORY),
+	CXL_CMD_VALIDATE(GET_LOG, MUTEX, 0x18, ~0, MANDATORY,
+			 validate_log_uuid),
 };
 
 #define cxl_for_each_cmd(cmd)                                                  \
@@ -515,6 +529,15 @@ static int handle_mailbox_cmd_from_user(struct cxl_memdev *cxlmd,
 	int rc;
 
 	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) {
+				cxl_mem_mbox_put(cxlmd->cxlm);
+				return -EFAULT;
+			}
+		}
+
 		/*
 		 * Directly copy the userspace payload into the hardware. UAPI
 		 * states that the buffer must already be little endian.
@@ -1063,6 +1086,23 @@ 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 commands taint except debug vendor log */
+	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)
 {
diff --git a/include/uapi/linux/cxl_mem.h b/include/uapi/linux/cxl_mem.h
index b504412d1db7..4c4a12c7a4d5 100644
--- a/include/uapi/linux/cxl_mem.h
+++ b/include/uapi/linux/cxl_mem.h
@@ -34,6 +34,7 @@ extern "C" {
 	C(IDENTIFY,	"Identify Command"),                                   \
 	C(RAW,		"Raw device command"),                                 \
 	C(GET_SUPPORTED_LOGS,		"Get Supported Logs"),                 \
+	C(GET_LOG,	"Get Log"),                                            \
 	C(MAX,		"Last command")
 #undef C
 #define C(a, b) CXL_MEM_COMMAND_ID_##a
