kconfig: fix segv fault in menuconfig

With specific configurations requesting help for certain
menu lines caused menuconfig to crash.
This was tracked down to a null pointer bug.
Thanks to "Miles Lane" <miles.lane@gmail.com> for inital reporting
and to Gabriel C <nix.or.die@googlemail.com> for the backtrace
that helped me locating the bug.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

1 files changed, 3 insertions, 2 deletions

diff --git a/scripts/kconfig/mconf.c b/scripts/kconfig/mconf.c
index 2ee12a744641..1935818040e2 100644
--- a/scripts/kconfig/mconf.c
+++ b/scripts/kconfig/mconf.c
@@ -357,8 +357,9 @@ static void get_symbol_str(struct gstr *r, struct symbol *sym)
         bool hit;
         struct property *prop;
 
-        str_printf(r, "Symbol: %s [=%s]\n", sym->name,
-                                       sym_get_string_value(sym));
+        if (sym && sym->name)
+                str_printf(r, "Symbol: %s [=%s]\n", sym->name,
+                                                    sym_get_string_value(sym));
         for_all_prompts(sym, prop)
                 get_prompt_str(r, prop);
         hit = false;