modbus: serial: Divide by zero check

javlands · henrikbrixandersen · commit 1a23d459bc14 · 2025-08-07T13:15:55.000+02:00
Check if the baudrate is not 0 before dividing by it
to get the rtu_timeout.

Signed-off-by: Jaro Van Landschoot &lt;jaro.vanlandschoot@basalte.be&gt;
diff --git a/subsys/modbus/modbus_serial.c b/subsys/modbus/modbus_serial.c
@@ -602,6 +602,11 @@ int modbus_serial_init(struct modbus_context *ctx,
 		}
 	}
 
+	if (param.serial.baud == 0) {
+		LOG_ERR("Baudrate is 0");
+		return -EINVAL;
+	}
+
 	if (param.serial.baud <= 38400) {
 		cfg->rtu_timeout = (numof_bits * if_delay_max) /
 				   param.serial.baud;

Original file line number	Diff line number	Diff line change
`@@ -602,6 +602,11 @@ int modbus_serial_init(struct modbus_context *ctx,`
`602`	`602`	`}`
`603`	`603`	`}`
`604`	`604`
	`605`	`+ if (param.serial.baud == 0) {`
	`606`	`+ LOG_ERR("Baudrate is 0");`
	`607`	`+ return -EINVAL;`
	`608`	`+ }`
	`609`	`+`
`605`	`610`	`if (param.serial.baud <= 38400) {`
`606`	`611`	`cfg->rtu_timeout = (numof_bits * if_delay_max) /`
`607`	`612`	`param.serial.baud;`