net: lwip: check if network device is available in do_dhcp
eth_get_dev() returns NULL if no network device is available.
Not checking the return value leads to a crash when the device
pointer is dereferenced.
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Jerome Forissier <jerome.forissier@linaro.org>
diff --git a/net/lwip/dhcp.c b/net/lwip/dhcp.c
index 9b882cf..e7d9147 100644
--- a/net/lwip/dhcp.c
+++ b/net/lwip/dhcp.c
@@ -3,6 +3,7 @@
#include <command.h>
#include <console.h>
+#include <log.h>
#include <dm/device.h>
#include <linux/delay.h>
#include <linux/errno.h>
@@ -112,10 +113,17 @@
int do_dhcp(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
{
int ret;
+ struct udevice *dev;
eth_set_current();
- ret = dhcp_loop(eth_get_dev());
+ dev = eth_get_dev();
+ if (!dev) {
+ log_err("No network device\n");
+ return CMD_RET_FAILURE;
+ }
+
+ ret = dhcp_loop(dev);
if (ret)
return ret;