Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
clockevents: Add missing resets of the next_event_forced flag
The prevention mechanism against timer interrupt starvation missed to reset the next_event_forced flag in a couple of places:
-
When the clock event state changes. That can cause the flag to be stale over a shutdown/startup sequence
-
When a non-forced event is armed, which then prevents rearming before that event. If that event is far out in the future this will cause missed timer interrupts.
-
In the suspend wakeup handler.
That led to stalls which have been reported by several people.
Add the missing resets, which fixes the problems for the reporters.
Details
- Affected product:
- AlmaLinux 9.2 ESU , CentOS 6 ELS , CentOS 7 ELS , CentOS 8.4 ELS , CentOS 8.5 ELS , CentOS Stream 8 ELS , CloudLinux 7 ELS , Oracle Linux 6 ELS , Oracle Linux 7 ELS , RHEL 7 ELS , TuxCare 9.6 ESU , Ubuntu 16.04 ELS , Ubuntu 18.04 ELS , Ubuntu 20.04 ELS
- Affected packages:
- kernel @ 4.18.0 (+15 more)
In the Linux kernel, the following vulnerability has been resolved:
clockevents: Add missing resets of the next_event_forced flag
The prevention mechanism against timer interrupt starvation missed to reset the next_event_forced flag in a couple of places:
-
When the clock event state changes. That can cause the flag to be stale over a shutdown/startup sequence
-
When a non-forced event is armed, which then prevents rearming before that event. If that event is far out in the future this will cause missed timer interrupts.
-
In the suspend wakeup handler.
That led to stalls which have been reported by several people.
Add the missing resets, which fixes the problems for the reporters.