Withdrawn by the publisher.

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

clocksource/drivers/timer-sp804: Fix an Oops when read_current_timer is called on ARM32 platforms where the SP804 is not registered as the sched_clock.

On SP804, the delay timer shares the same clkevt instance with sched_clock. On some platforms, when sp804_clocksource_and_sched_clock_init is called with use_sched_clock not set to 1, sched_clkevt is not properly initialized. However, sp804_register_delay_timer is invoked unconditionally, and read_current_timer() subsequently calls sp804_read on an uninitialized sched_clkevt, leading to a kernel Oops when accessing sched_clkevt->value.

Declare a dedicated clkevt instance exclusively for delay timer, instead of sharing the same clkevt with sched_clock. This ensures that read_current_timer continues to work correctly regardless of whether SP804 is selected as the sched_clock.

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

clocksource/drivers/timer-sp804: Fix an Oops when read_current_timer is called on ARM32 platforms where the SP804 is not registered as the sched_clock.

On SP804, the delay timer shares the same clkevt instance with sched_clock. On some platforms, when sp804_clocksource_and_sched_clock_init is called with use_sched_clock not set to 1, sched_clkevt is not properly initialized. However, sp804_register_delay_timer is invoked unconditionally, and read_current_timer() subsequently calls sp804_read on an uninitialized sched_clkevt, leading to a kernel Oops when accessing sched_clkevt->value.

Declare a dedicated clkevt instance exclusively for delay timer, instead of sharing the same clkevt with sched_clock. This ensures that read_current_timer continues to work correctly regardless of whether SP804 is selected as the sched_clock.

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 85 more

In the Linux kernel, the following vulnerability has been resolved: clocksource/drivers/timer-sp804: Fix an Oops when read_current_timer is called on ARM32 platforms where the SP804 is not registered as the sched_clock. On SP804, the delay timer shares the same clkevt instance with sched_clock. On some platforms, when sp804_clocksource_and_sched_clock_init is called with use_sched_clock not set to 1, sched_clkevt is not properly initialized. However, sp804_register_delay_timer is invoked unconditionally, and read_current_timer() subsequently calls sp804_read on an uninitialized sched_clkevt, leading to a kernel Oops when accessing sched_clkevt->value. Declare a dedicated clkevt instance exclusively for delay timer, instead of sharing the same clkevt with sched_clock. This ensures that read_current_timer continues to work correctly regardless of whether SP804 is selected as the sched_clock.

Ein Angreifer kann mehrere Schwachstellen im Linux Kernel ausnutzen, um einen Denial of Service Angriff durchzuführen oder nicht bekannte Auswirkungen zu erzielen.