Harden dmi_string() calls with better NULL checks

This patch fixes more potential issues where dmi_string() results
was not necessarily checked for NULL, which potentially could lead
to SEGV issues.

Signed-off-by: David Sommerseth <davids@redhat.com>

1 files changed, 11 insertions, 2 deletions

diff --git a/src/dmioem.c b/src/dmioem.c
index 361810a..67cd517 100644
--- a/src/dmioem.c
+++ b/src/dmioem.c
@@ -40,10 +40,19 @@ static enum DMI_VENDORS dmi_vendor = VENDOR_UNKNOWN;
  * value if we know how to decode at least one specific entry type for
  * that vendor.
  */
-void dmi_set_vendor(const char *s)
+void dmi_set_vendor(const struct dmi_header *h)
 {
-        if(strcmp(s, "HP") == 0)
+        const char *vendor;
+
+        if( !h || !h->data ) {
+                return;
+        }
+        vendor = dmi_string(h, h->data[0x04]);
+        if( !vendor ) {
+                return;
+        } else if(strcmp(vendor, "HP") == 0) {
                 dmi_vendor = VENDOR_HP;
+        }
 }
 
 /*