From cf64bfef77d4a5205ced84cee579aacb73af239d Mon Sep 17 00:00:00 2001 From: Baptiste Daroussin Date: Tue, 6 Oct 2020 08:18:09 +0000 Subject: [PATCH] backlight: check the lenght if the input before trimming '%' Reported by: hps Reviewed by: manu Differential Revision: https://reviews.freebsd.org/D26693 --- usr.bin/backlight/backlight.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/usr.bin/backlight/backlight.c b/usr.bin/backlight/backlight.c index a68876861adf..1dae0cfe5c62 100644 --- a/usr.bin/backlight/backlight.c +++ b/usr.bin/backlight/backlight.c @@ -145,7 +145,8 @@ main(int argc, char *argv[]) if (argc == 1) { /* ignore a trailing % for user friendlyness */ - if (argv[0][strlen(argv[0]) - 1] == '%') + if (strlen(argv[0]) > 0 && + argv[0][strlen(argv[0]) - 1] == '%') argv[0][strlen(argv[0]) - 1] = '\0'; percent = strtonum(argv[0], 0, 100, &percent_error); if (percent_error)