diff --git a/target/linux/realtek/files-6.18/drivers/net/dsa/rtl83xx/l3.c b/target/linux/realtek/files-6.18/drivers/net/dsa/rtl83xx/l3.c
index a50edc54e7b..f81ee170cee 100644
--- a/target/linux/realtek/files-6.18/drivers/net/dsa/rtl83xx/l3.c
+++ b/target/linux/realtek/files-6.18/drivers/net/dsa/rtl83xx/l3.c
@@ -785,6 +785,7 @@ static int otto_l3_alloc_egress_intf(struct otto_l3_ctrl *ctrl, u64 mac, int vla
 
 	if (free_mac < 0) {
 		dev_err(ctrl->dev, "No free egress interface, cannot offload\n");
+		mutex_unlock(ctrl->lock);
 		return -1;
 	}