kconfig: fix possible buffer overflow

Buffer 'new_argv' is accessed without bound check after accessing with
bound check via 'new_argc' index.

Fixes: e298f3b49def ("kconfig: add built-in function support")
Co-developed-by: Ivanov Mikhail <ivanov.mikhail1@huawei-partners.com>
Signed-off-by: Konstantin Meskhidze <konstantin.meskhidze@huawei.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

diff --git a/scripts/kconfig/preprocess.c b/scripts/kconfig/preprocess.c
index 748da57..d1f5bcf 100644 (file)
--- a/scripts/kconfig/preprocess.c
+++ b/scripts/kconfig/preprocess.c
@@ -396,6 +396,9 @@ static char *eval_clause(const char *str, size_t len, int argc, char *argv[])
 
                p++;
        }
+
+       if (new_argc >= FUNCTION_MAX_ARGS)
+               pperror("too many function arguments");
        new_argv[new_argc++] = prev;
 
        /*