diff --git a/src/cndm/modules/cndm/cndm.h b/src/cndm/modules/cndm/cndm.h
index 0c8649e..be18897 100644
--- a/src/cndm/modules/cndm/cndm.h
+++ b/src/cndm/modules/cndm/cndm.h
@@ -51,6 +51,8 @@ struct cndm_dev {
 	phys_addr_t hw_regs_phys;
 	void __iomem *hw_addr;
 
+	struct mutex mbox_lock;
+
 	u32 port_count;
 	u32 port_offset;
 	u32 port_stride;
diff --git a/src/cndm/modules/cndm/cndm_cmd.c b/src/cndm/modules/cndm/cndm_cmd.c
index 01bb8bd..5aed20a 100644
--- a/src/cndm/modules/cndm/cndm_cmd.c
+++ b/src/cndm/modules/cndm/cndm_cmd.c
@@ -17,6 +17,8 @@ int cndm_exec_mbox_cmd(struct cndm_dev *cdev, void *cmd, void *rsp)
 	if (!cmd || !rsp)
 		return -EINVAL;
 
+	mutex_lock(&cdev->mbox_lock);
+
 	// write command to mailbox
 	for (k = 0; k < 16; k++) {
 		iowrite32(*((u32 *)(cmd + k*4)), cdev->hw_addr + 0x10000 + k*4);
@@ -38,6 +40,9 @@ int cndm_exec_mbox_cmd(struct cndm_dev *cdev, void *cmd, void *rsp)
 	for (k = 0; k < 16; k++) {
 		*((u32 *)(rsp + k*4)) = ioread32(cdev->hw_addr + 0x10000 + 0x40 + k*4);
 	}
+
+	mutex_unlock(&cdev->mbox_lock);
+
 	return 0;
 }
 
diff --git a/src/cndm/modules/cndm/cndm_main.c b/src/cndm/modules/cndm/cndm_main.c
index 7951a79..510fb4a 100644
--- a/src/cndm/modules/cndm/cndm_main.c
+++ b/src/cndm/modules/cndm/cndm_main.c
@@ -47,6 +47,8 @@ static int cndm_common_probe(struct cndm_dev *cdev)
 	int ret = 0;
 	int k;
 
+	mutex_init(&cdev->mbox_lock);
+
 #if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 15, 0)
 	devlink_register(devlink);
 #else