stuartl/linux-stable
1
0
Fork 0
mirror of https://kernel.googlesource.com/pub/scm/linux/kernel/git/stable/linux-stable.git synced 2025-10-14 23:14:29 +10:00
Code Issues Releases Wiki Activity

rtc: check if __rtc_read_time was successful in rtc_timer_do_work()

Browse Source 
[ Upstream commit e8ba8a2bc4 ]

If the __rtc_read_time call fails,, the struct rtc_time tm; may contain
uninitialized data, or an illegal date/time read from the RTC hardware.

When calling rtc_tm_to_ktime later, the result may be a very large value
(possibly KTIME_MAX). If there are periodic timers in rtc->timerqueue,
they will continually expire, may causing kernel softlockup.

Fixes: 6610e0893b ("RTC: Rework RTC code to use timerqueue for events")
Signed-off-by: Yongliang Gao <leonylgao@tencent.com>
Acked-by: Jingqun Li <jingqunli@tencent.com>
Link: https://lore.kernel.org/r/20241011043153.3788112-1-leonylgao@gmail.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Yongliang Gao 2024-10-11 12:31:53 +08:00 committed by Greg Kroah-Hartman
parent cd15481285
commit 0d68e8514d
1 changed files with 6 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
drivers/rtc/interface.c
View File

@ -907,13 +907,18 @@ void rtc_timer_do_work(struct work_struct *work)
struct timerqueue_node *next;
ktime_t now;
struct rtc_time tm;
int err;
struct rtc_device *rtc =
container_of(work, struct rtc_device, irqwork);
mutex_lock(&rtc->ops_lock);
again:
__rtc_read_time(rtc, &tm);
err = __rtc_read_time(rtc, &tm);
if (err) {
mutex_unlock(&rtc->ops_lock);
return;
}
now = rtc_tm_to_ktime(tm);
while ((next = timerqueue_getnext(&rtc->timerqueue))) {
if (next->expires > now)