| Message ID | 20180319234817.16199-1-alexandre.belloni@bootlin.com |
|---|---|
| State | Accepted |
| Headers | show |
| Series | [1/6] rtc: hctosys: Ensure system time doesn't overflow time_t | expand |
diff --git a/drivers/rtc/hctosys.c b/drivers/rtc/hctosys.c index e1cfa06810ef..e79f2a181ad2 100644 --- a/drivers/rtc/hctosys.c +++ b/drivers/rtc/hctosys.c @@ -49,6 +49,11 @@ static int __init rtc_hctosys(void) tv64.tv_sec = rtc_tm_to_time64(&tm); +#if BITS_PER_LONG == 32 + if (tv64.tv_sec > INT_MAX) + goto err_read; +#endif + err = do_settimeofday64(&tv64); dev_info(rtc->dev.parent,
On 32bit platforms, time_t is still a signed 32bit long. If it is overflowed, userspace and the kernel cant agree on the current system time. This causes multiple issues, in particular with systemd: https://github.com/systemd/systemd/issues/1143 A good workaround is to simply avoid using systohc which is something I greatly encourage as the time is better set by userspace. However, many distribution enable it and use systemd which is rendering the system unusable in case the RTC holds a date after 2038 (and more so after 2106). Many drivers have workaround for this case and they should be eliminated so there is only one place left to fix when userspace is able to cope with dates after the 31bit overflow. Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> --- drivers/rtc/hctosys.c | 5 +++++ 1 file changed, 5 insertions(+)