diff --git a/code/application/source/sf_app/code/source/app/sf_service.c b/code/application/source/sf_app/code/source/app/sf_service.c
index a7fc6e547..060541700 100755
--- a/code/application/source/sf_app/code/source/app/sf_service.c
+++ b/code/application/source/sf_app/code/source/app/sf_service.c
@@ -2104,6 +2104,7 @@ SINT32 sf_app_to_cardv_hd_ture(void) {
     return s32ret;
 }
 
+
 int sf_check_eth0(void)
 {
     FILE *fp;
@@ -2121,7 +2122,16 @@ int sf_check_eth0(void)
         free(output);
         return 1;
     }
-    fgets(output, len, fp);
+
+    // Check if fgets was successful
+    if (fgets(output, len, fp) == NULL) {
+        MLOGE("Error reading from ifconfig output\n");
+        pclose(fp);
+        free(output);
+        return 1;
+    }
+
+    // Check if usb0 exists
     if (strstr(output, "eth0") == NULL) {
         MLOGI("The network card does not exist\n");
         pclose(fp);
@@ -2129,7 +2139,15 @@ int sf_check_eth0(void)
         return 1;
     }
 
-    fgets(output, len, fp);
+    // Read the second line
+    if (fgets(output, len, fp) == NULL) {
+        MLOGE("Error reading from ifconfig output\n");
+        pclose(fp);
+        free(output);
+        return 1;
+    }
+
+    // Check if an IP address is assigned
     if (strstr(output, "inet ") == NULL) {
         MLOGI("The network card exists, but no IP address has been assigned\n");
         pclose(fp);
@@ -2137,11 +2155,17 @@ int sf_check_eth0(void)
         return 1;
     }
 
+    // Extract IP address
     char *ip_address_start = strstr(output, "inet ") + strlen("inet ");
     char *ip_address_end = strchr(ip_address_start, ' ');
-    *ip_address_end = '\0';
 
-    MLOGI("IP address of network card eth0: %s\n", ip_address_start);
+    // Check if ip_address_end is NULL before dereferencing
+    if (ip_address_end != NULL) {
+        *ip_address_end = '\0';
+        MLOGI("IP address of network card eth0: %s\n", ip_address_start);
+    } else {
+        MLOGE("Error extracting IP address\n");
+    }
 
     pclose(fp);
     free(output);
@@ -2164,7 +2188,16 @@ int sf_check_usb0(void)
         free(output);
         return 1;
     }
-    fgets(output, len, fp);
+
+    // Check if fgets was successful
+    if (fgets(output, len, fp) == NULL) {
+        MLOGE("Error reading from ifconfig output\n");
+        pclose(fp);
+        free(output);
+        return 1;
+    }
+
+    // Check if usb0 exists
     if (strstr(output, "usb0") == NULL) {
         MLOGI("The network card does not exist\n");
         pclose(fp);
@@ -2172,7 +2205,15 @@ int sf_check_usb0(void)
         return 1;
     }
 
-    fgets(output, len, fp);
+    // Read the second line
+    if (fgets(output, len, fp) == NULL) {
+        MLOGE("Error reading from ifconfig output\n");
+        pclose(fp);
+        free(output);
+        return 1;
+    }
+
+    // Check if an IP address is assigned
     if (strstr(output, "inet ") == NULL) {
         MLOGI("The network card exists, but no IP address has been assigned\n");
         pclose(fp);
@@ -2180,11 +2221,17 @@ int sf_check_usb0(void)
         return 1;
     }
 
+    // Extract IP address
     char *ip_address_start = strstr(output, "inet ") + strlen("inet ");
     char *ip_address_end = strchr(ip_address_start, ' ');
-    *ip_address_end = '\0';
 
-    MLOGI("IP address of network card usb0: %s\n", ip_address_start);
+    // Check if ip_address_end is NULL before dereferencing
+    if (ip_address_end != NULL) {
+        *ip_address_end = '\0';
+        MLOGI("IP address of network card usb0: %s\n", ip_address_start);
+    } else {
+        MLOGE("Error extracting IP address\n");
+    }
 
     pclose(fp);
     free(output);