ac14xx: fix a potential NULL deref in diagnostics

getenv() immediately after setenv() may perfectly legally return NULL, so
make sure to not deference an invalid pointer when creating diagnostic output

Signed-off-by: Gerhard Sittig <gsi@denx.de>

diff --git a/board/ifm/ac14xx/ac14xx.c b/board/ifm/ac14xx/ac14xx.c
index 7442591..f200b45 100644 (file)
--- a/board/ifm/ac14xx/ac14xx.c
+++ b/board/ifm/ac14xx/ac14xx.c
@@ -209,6 +209,7 @@ static int read_eeprom(void)
 int mac_read_from_eeprom(void)
 {
        const u8 *mac;
+       const char *mac_txt;
 
        if (read_eeprom()) {
                printf("I2C EEPROM read failed.\n");
@@ -230,8 +231,11 @@ int mac_read_from_eeprom(void)
 
        if (mac && is_valid_ether_addr(mac)) {
                eth_setenv_enetaddr("ethaddr", mac);
-               printf("DIAG: %s() MAC value [%s]\n",
-                       __func__, getenv("ethaddr"));
+               mac_txt = getenv("ethaddr");
+               if (mac_txt)
+                       printf("DIAG: MAC value [%s]\n", mac_txt);
+               else
+                       printf("DIAG: failed to setup MAC env\n");
        }
 
        return 0;