Описание
In the Linux kernel, the following vulnerability has been resolved:
clocksource/drivers/sh_tmu: Always leave device running after probe
The TMU device can be used as both a clocksource and a clockevent provider. The driver tries to be smart and power itself on and off, as well as enabling and disabling its clock when it's not in operation. This behavior is slightly altered if the TMU is used as an early platform device in which case the device is left powered on after probe, but the clock is still enabled and disabled at runtime.
This has worked for a long time, but recent improvements in PREEMPT_RT and PROVE_LOCKING have highlighted an issue. As the TMU registers itself as a clockevent provider, clockevents_register_device(), it needs to use raw spinlocks internally as this is the context of which the clockevent framework interacts with the TMU driver. However in the context of holding a raw spinlock the TMU driver can't really manage its power state or clock with calls to pm_ru...
In the Linux kernel, the following vulnerability has been resolved:
clocksource/drivers/sh_tmu: Always leave device running after probe
The TMU device can be used as both a clocksource and a clockevent provider. The driver tries to be smart and power itself on and off, as well as enabling and disabling its clock when it's not in operation. This behavior is slightly altered if the TMU is used as an early platform device in which case the device is left powered on after probe, but the clock is still enabled and disabled at runtime.
This has worked for a long time, but recent improvements in PREEMPT_RT and PROVE_LOCKING have highlighted an issue. As the TMU registers itself as a clockevent provider, clockevents_register_device(), it needs to use raw spinlocks internally as this is the context of which the clockevent framework interacts with the TMU driver. However in the context of holding a raw spinlock the TMU driver can't really manage its power state or clock with calls to pm_runtime_() and clk_() as these calls end up in other platform drivers using regular spinlocks to control power and clocks.
This mix of spinlock contexts trips a lockdep warning.
For non-PREEMPT_RT builds this is not really an issue, but for PREEMPT_RT builds where normal spinlocks can sleep this might be an issue. Be cautious and always leave the power and clock running after probe.
Ссылки
- https://nvd.nist.gov/vuln/detail/CVE-2026-43227
- https://git.kernel.org/stable/c/016476afef993d1201a19decc9b5b2ea1e6620f2
- https://git.kernel.org/stable/c/0e513cc6b9cea190fe342cc222b1054e7e8acfc8
- https://git.kernel.org/stable/c/6f113ab549b864c1bc57d4f89846ee335394089a
- https://git.kernel.org/stable/c/79d650695773f03de36b99228a090d33d1c18264
- https://git.kernel.org/stable/c/88c76792180dffd83f1c5b9dc8fdaeb145cb94e0
- https://git.kernel.org/stable/c/b1278972b08e480990e2789bdc6a7c918bc349be
- https://git.kernel.org/stable/c/bc59d5f3afe41fec5d673c27c703b761ae578d28
- https://git.kernel.org/stable/c/f0b31247e7d67a943b3a09d3cef7c0ae788d88e6
Связанные уязвимости
In the Linux kernel, the following vulnerability has been resolved: clocksource/drivers/sh_tmu: Always leave device running after probe The TMU device can be used as both a clocksource and a clockevent provider. The driver tries to be smart and power itself on and off, as well as enabling and disabling its clock when it's not in operation. This behavior is slightly altered if the TMU is used as an early platform device in which case the device is left powered on after probe, but the clock is still enabled and disabled at runtime. This has worked for a long time, but recent improvements in PREEMPT_RT and PROVE_LOCKING have highlighted an issue. As the TMU registers itself as a clockevent provider, clockevents_register_device(), it needs to use raw spinlocks internally as this is the context of which the clockevent framework interacts with the TMU driver. However in the context of holding a raw spinlock the TMU driver can't really manage its power state or clock with calls to pm_runti...
In the Linux kernel, the following vulnerability has been resolved: clocksource/drivers/sh_tmu: Always leave device running after probe The TMU device can be used as both a clocksource and a clockevent provider. The driver tries to be smart and power itself on and off, as well as enabling and disabling its clock when it's not in operation. This behavior is slightly altered if the TMU is used as an early platform device in which case the device is left powered on after probe, but the clock is still enabled and disabled at runtime. This has worked for a long time, but recent improvements in PREEMPT_RT and PROVE_LOCKING have highlighted an issue. As the TMU registers itself as a clockevent provider, clockevents_register_device(), it needs to use raw spinlocks internally as this is the context of which the clockevent framework interacts with the TMU driver. However in the context of holding a raw spinlock the TMU driver can't really manage its power state or clock with calls to pm_runti...
In the Linux kernel, the following vulnerability has been resolved: clocksource/drivers/sh_tmu: Always leave device running after probe The TMU device can be used as both a clocksource and a clockevent provider. The driver tries to be smart and power itself on and off, as well as enabling and disabling its clock when it's not in operation. This behavior is slightly altered if the TMU is used as an early platform device in which case the device is left powered on after probe, but the clock is still enabled and disabled at runtime. This has worked for a long time, but recent improvements in PREEMPT_RT and PROVE_LOCKING have highlighted an issue. As the TMU registers itself as a clockevent provider, clockevents_register_device(), it needs to use raw spinlocks internally as this is the context of which the clockevent framework interacts with the TMU driver. However in the context of holding a raw spinlock the TMU driver can't really manage its power state or clock with calls to pm_runti
In the Linux kernel, the following vulnerability has been resolved: c ...