From fe0586347ee46f927ae27bb9673532da9f5dead5 Mon Sep 17 00:00:00 2001 From: Daniel Axtens Date: Mon, 11 Jan 2021 17:30:42 +1100 Subject: [PATCH] script/execute: Avoid crash when using "$#" outside a function scope "$#" represents the number of arguments to a function. It is only defined in a function scope, where "scope" is non-NULL. Currently, if we attempt to evaluate "$#" outside a function scope, "scope" will be NULL and we will crash with a NULL pointer dereference. Do not attempt to count arguments for "$#" if "scope" is NULL. This will result in "$#" being interpreted as an empty string if evaluated outside a function scope. Signed-off-by: Daniel Axtens Reviewed-by: Daniel Kiper Signed-off-by: Stefan Sørensen --- grub-core/script/execute.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/grub-core/script/execute.c b/grub-core/script/execute.c index 5ea2aef..23d34bd 100644 --- a/grub-core/script/execute.c +++ b/grub-core/script/execute.c @@ -485,7 +485,7 @@ gettext_putvar (const char *str, grub_size_t len, return 0; /* Enough for any number. */ - if (len == 1 && str[0] == '#') + if (len == 1 && str[0] == '#' && scope != NULL) { grub_snprintf (*ptr, 30, "%u", scope->argv.argc); *ptr += grub_strlen (*ptr); -- 2.14.2