Commit 61b2dbb8 authored by Guillem Jover's avatar Guillem Jover

Fix dehumanize_number() to correctly detect overflows

Do not allow numbers greated than INT64_MAX and smaller than INT64_MIN.
Clarify the positive sign value by prefixing it with an explicit +.

Fixes: https://bugs.freedesktop.org/show_bug.cgi?id=66909
parent 11941746
/*
* Copyright © 2012 Guillem Jover <guillem@hadrons.org>
* Copyright © 2012-2013 Guillem Jover <guillem@hadrons.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
......@@ -35,8 +35,8 @@
int
dehumanize_number(const char *buf, int64_t *num)
{
uint64_t rval;
int sign = 1;
uint64_t rval, rmax;
int sign = +1;
int rc;
/* The current expand_number() implementation uses bit shifts, so
......@@ -52,7 +52,13 @@ dehumanize_number(const char *buf, int64_t *num)
rc = expand_number(buf, &rval);
if (rc < 0)
return rc;
if (rval == UINT64_MAX && sign == -1) {
/* The sign has been stripped, so rval has the absolute value.
* Error out, regardless of the sign, if rval is greater than
* abs(INT64_MIN) (== INT64_MAX + 1), or if the sign is positive
* and the value has overflown by one (INT64_MAX + 1). */
rmax = INT64_MAX + 1ULL;
if (rval > rmax || (rval == rmax && sign == +1)) {
errno = ERANGE;
return -1;
}
......
......@@ -25,6 +25,7 @@
*/
#include <assert.h>
#include <errno.h>
#include <stdlib.h>
int
......@@ -60,5 +61,17 @@ main(int argc, char **argv)
assert(dehumanize_number("-3G", &val) == 0);
assert(val == -3221225472LL);
assert(dehumanize_number("9223372036854775807", &val) == 0);
assert(val == INT64_MAX);
assert(dehumanize_number("9223372036854775808", &val) == -1);
assert(errno == ERANGE);
assert(dehumanize_number("-9223372036854775808", &val) == 0);
assert(val == INT64_MIN);
assert(dehumanize_number("-9223372036854775809", &val) == -1);
assert(errno == ERANGE);
return 0;
}
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