From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 From: Aaron Miller Date: Fri, 29 Jul 2016 17:41:27 +0800 Subject: [PATCH] misc: fix invalid character recongition in strto*l Would previously allow digits larger than the base and didn't check that subtracting the difference from 0-9 to lowercase letters for characters larger than 9 didn't result in a value lower than 9, which allowed the parses: ` = 9, _ = 8, ^ = 7, ] = 6, \ = 5, and [ = 4 --- grub-core/kern/misc.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/grub-core/kern/misc.c b/grub-core/kern/misc.c index 0e89c483d5e..5c3899f0e5b 100644 --- a/grub-core/kern/misc.c +++ b/grub-core/kern/misc.c @@ -434,11 +434,14 @@ grub_strtoull (const char *str, char **end, int base) unsigned long digit; digit = grub_tolower (*str) - '0'; - if (digit >= 'a' - '0') - digit += '0' - 'a' + 10; - else if (digit > 9) - break; - + if (digit > 9) + { + digit += '0' - 'a' + 10; + /* digit <= 9 check is needed to keep chars larger than + '9' but less than 'a' from being read as numbers */ + if (digit >= (unsigned long) base || digit <= 9) + break; + } if (digit >= (unsigned long) base) break;