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calendarspec: improve overflow handling

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Check if the parsed seconds value fits in an integer *after*
multiplying by USEC_PER_SEC, otherwise a large value can trigger
modulo by zero during normalization.
This commit is contained in:
Douglas Christman 2016-12-20 16:42:12 -05:00
parent 9f702d00d6
commit c0aebb4b3b
2 changed files with 9 additions and 6 deletions
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13
src/basic/calendarspec.c
View file

@ -20,6 +20,7 @@
#include <alloca.h>
#include <ctype.h>
#include <errno.h>
#include <limits.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
@ -96,7 +97,7 @@ static void normalize_chain(CalendarComponent **c) {
* While we're counting the chain, also normalize `stop`
* so the length of the range is a multiple of `repeat`
*/
if (i->stop > i->start)
if (i->stop > i->start && i->repeat > 0)
i->stop -= (i->stop - i->start) % i->repeat;
}
@ -487,7 +488,7 @@ static int parse_weekdays(const char **p, CalendarSpec *c) {
}
}
static int parse_component_decimal(const char **p, bool usec, unsigned long *res) {
static int parse_component_decimal(const char **p, bool usec, int *res) {
unsigned long value;
const char *e = NULL;
char *ee = NULL;
@ -502,8 +503,6 @@ static int parse_component_decimal(const char **p, bool usec, unsigned long *res
return -errno;
if (ee == *p)
return -EINVAL;
if ((unsigned long) (int) value != value)
return -ERANGE;
e = ee;
if (usec) {
@ -530,6 +529,9 @@ static int parse_component_decimal(const char **p, bool usec, unsigned long *res
}
finish:
if (value > INT_MAX)
return -ERANGE;
*p = e;
*res = value;
@ -556,9 +558,8 @@ static int const_chain(int value, CalendarComponent **c) {
}
static int prepend_component(const char **p, bool usec, CalendarComponent **c) {
unsigned long start, stop = -1, repeat = 0;
int r, start, stop = -1, repeat = 0;
CalendarComponent *cc;
int r;
const char *e;
assert(p);

2
src/test/test-calendarspec.c
View file

@ -238,6 +238,8 @@ int main(int argc, char* argv[]) {
assert_se(calendar_spec_from_string("*:05..10/6", &c) < 0);
assert_se(calendar_spec_from_string("20/4:00", &c) < 0);
assert_se(calendar_spec_from_string("00:00/60", &c) < 0);
assert_se(calendar_spec_from_string("00:00:2300", &c) < 0);
assert_se(calendar_spec_from_string("00:00:18446744073709551615", &c) < 0);
test_timestamp();
test_hourly_bug_4031();