Affected: Alpaquita:25: linux-lts, Alpaquita:stream: linux-lts

In the Linux kernel, the following vulnerability has been resolved:

drm/imagination: Fix kernel crash when hard resetting the GPU

The GPU hard reset sequence calls pm_runtime_force_suspend() and pm_runtime_force_resume(), which according to their documentation should only be used during system-wide PM transitions to sleep states.

The main issue though is that depending on some internal runtime PM state as seen by pm_runtime_force_suspend() (whether the usage count is <= 1), pm_runtime_force_resume() might not resume the device unless needed. If that happens, the runtime PM resume callback pvr_power_device_resume() is not called, the GPU clocks are not re-enabled, and the kernel crashes on the next attempt to access GPU registers as part of the power-on sequence.

Replace calls to pm_runtime_force_suspend() and pm_runtime_force_resume() with direct calls to the driver's runtime PM callbacks, pvr_power_device_suspend() and pvr_power_device_resume(), to ensure clocks are re-enabled and avoid the kernel crash.

In the Linux kernel, the following vulnerability has been resolved:

drm/imagination: Fix kernel crash when hard resetting the GPU

The GPU hard reset sequence calls pm_runtime_force_suspend() and pm_runtime_force_resume(), which according to their documentation should only be used during system-wide PM transitions to sleep states.

The main issue though is that depending on some internal runtime PM state as seen by pm_runtime_force_suspend() (whether the usage count is <= 1), pm_runtime_force_resume() might not resume the device unless needed. If that happens, the runtime PM resume callback pvr_power_device_resume() is not called, the GPU clocks are not re-enabled, and the kernel crashes on the next attempt to access GPU registers as part of the power-on sequence.

Replace calls to pm_runtime_force_suspend() and pm_runtime_force_resume() with direct calls to the driver's runtime PM callbacks, pvr_power_device_suspend() and pvr_power_device_resume(), to ensure clocks are re-enabled and avoid the kernel crash.

Security update for the Linux Kernel

Security update for the Linux Kernel

Affected: Ubuntu:16.04:LTS: linux-hwe-edge, Ubuntu:18.04:LTS: linux-aws-5.0, Ubuntu:18.04:LTS: linux-aws-5.3, Ubuntu:18.04:LTS: linux-azure, Ubuntu:18.04:LTS: linux-azure-5.3, Ubuntu:18.04:LTS: linux-azure-edge, Ubuntu:18.04:LTS: linux-gcp, Ubuntu:18.04:LTS: linux-gcp-5.3, Ubuntu:18.04:LTS: linux-gke-4.15, Ubuntu:18.04:LTS: linux-gke-5.4 and 123 more

In the Linux kernel, the following vulnerability has been resolved: drm/imagination: Fix kernel crash when hard resetting the GPU The GPU hard reset sequence calls pm_runtime_force_suspend() and pm_runtime_force_resume(), which according to their documentation should only be used during system-wide PM transitions to sleep states. The main issue though is that depending on some internal runtime PM state as seen by pm_runtime_force_suspend() (whether the usage count is <= 1), pm_runtime_force_resume() might not resume the device unless needed. If that happens, the runtime PM resume callback pvr_power_device_resume() is not called, the GPU clocks are not re-enabled, and the kernel crashes on the next attempt to access GPU registers as part of the power-on sequence. Replace calls to pm_runtime_force_suspend() and pm_runtime_force_resume() with direct calls to the driver's runtime PM callbacks, pvr_power_device_suspend() and pvr_power_device_resume(), to ensure clocks are re-enabled and avoid the kernel crash.

Ein Angreifer kann mehrere Schwachstellen im Linux Kernel ausnutzen, um einen Denial of Service Angriff durchzuführen oder andere nicht spezifizierte Angriffe durchzuführen.