I2c Module Vulnerability in Linux Kernel Affects ACPI Devices

CVE-2024-45029

What is CVE-2024-45029?

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

i2c: tegra: Do not mark ACPI devices as irq safe

On ACPI machines, the tegra i2c module encounters an issue due to a mutex being called inside a spinlock. This leads to the following bug:

BUG: sleeping function called from invalid context at kernel/locking/mutex.c:585
...

Call trace:
__might_sleep
__mutex_lock_common
mutex_lock_nested
acpi_subsys_runtime_resume
rpm_resume
tegra_i2c_xfer

The problem arises because during __pm_runtime_resume(), the spinlock &dev->power.lock is acquired before rpm_resume() is called. Later, rpm_resume() invokes acpi_subsys_runtime_resume(), which relies on mutexes, triggering the error.

To address this issue, devices on ACPI are now marked as not IRQ-safe, considering the dependency of acpi_subsys_runtime_resume() on mutexes.

References