This is a note to let you know that I've just added the patch titled
rtc: check if __rtc_read_time was successful in rtc_timer_do_work()
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
rtc-check-if-__rtc_read_time-was-successful-in-rtc_t.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 749326f584ce243af77d538ebe6902c280981ca7
Author: Yongliang Gao <leonylgao@xxxxxxxxxxx>
Date: Fri Oct 11 12:31:53 2024 +0800
rtc: check if __rtc_read_time was successful in rtc_timer_do_work()
[ Upstream commit e8ba8a2bc4f60a1065f23d6a0e7cbea945a0f40d ]
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: 6610e0893b8b ("RTC: Rework RTC code to use timerqueue for events")
Signed-off-by: Yongliang Gao <leonylgao@xxxxxxxxxxx>
Acked-by: Jingqun Li <jingqunli@xxxxxxxxxxx>
Link: https://lore.kernel.org/r/20241011043153.3788112-1-leonylgao@xxxxxxxxx
Signed-off-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c
index 0b23706d9fd3c..4a7c41a6c21e7 100644
--- a/drivers/rtc/interface.c
+++ b/drivers/rtc/interface.c
@@ -904,13 +904,18 @@ 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)
