Messages in this thread Patch in this message | | | Date | Mon, 6 Jul 2009 06:11:08 -0400 | From | Amerigo Wang <> | Subject | [Patch] lib: make strict_strtoul() more strict |
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Let strict_strtoul() to reject strings longer than ULONG_MAX's string.
So does strict_stroull().
Update their documents.
(Tested on x86_64.)
Signed-off-by: WANG Cong <amwang@redhat.com> Cc: akpm@linux-foundation.org
--- diff --git a/lib/vsprintf.c b/lib/vsprintf.c index 756ccaf..f1f7bd7 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -143,7 +143,8 @@ long long simple_strtoll(const char *cp, char **endp, unsigned int base) * @res: The converted result value * * strict_strtoul converts a string to an unsigned long only if the - * string is really an unsigned long string, any string containing + * string is really an unsigned long string, any string has more than the + * number of digits in ULONG_MAX will be rejected, any string containing * any invalid char at the tail will be rejected and -EINVAL is returned, * only a newline char at the tail is acceptible because people generally * change a module parameter in the following way: @@ -168,6 +169,8 @@ int strict_strtoul(const char *cp, unsigned int base, unsigned long *res) len = strlen(cp); if (len == 0) return -EINVAL; + if (len > snprintf(NULL, 0, "%ld", ULONG_MAX)) + return -EINVAL; val = simple_strtoul(cp, &tail, base); if (tail == cp) @@ -216,7 +219,8 @@ EXPORT_SYMBOL(strict_strtol); * @res: The converted result value * * strict_strtoull converts a string to an unsigned long long only if the - * string is really an unsigned long long string, any string containing + * string is really an unsigned long long string, any string has more than + * the number of digits in ULLONG_MAX will be rejected, any string containing * any invalid char at the tail will be rejected and -EINVAL is returned, * only a newline char at the tail is acceptible because people generally * change a module parameter in the following way: @@ -241,6 +245,8 @@ int strict_strtoull(const char *cp, unsigned int base, unsigned long long *res) len = strlen(cp); if (len == 0) return -EINVAL; + if (len > snprintf(NULL, 0, "%lld", ULLONG_MAX)) + return -EINVAL; val = simple_strtoull(cp, &tail, base); if (tail == cp)
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