CVE-2024-49985 Information

Description

In the Linux kernel the following vulnerability has been resolved:

i2c: stm32f7: Do not prepare/unprepare clock during runtime suspend/resume

In case there is any sort of clock controller attached to this I2C bus controller for example Versaclock or even an AIC32x4 I2C codec then an I2C transfer triggered from the clock controller clk_ops .prepare callback may trigger a deadlock on drivers/clk/clk.c prepare_lock mutex.

This is because the clock controller first grabs the prepare_lock mutex and then performs the prepare operation including its I2C access. The I2C access resumes this I2C bus controller via .runtime_resume callback which calls clk_prepare_enable() which attempts to grab the prepare_lock mutex again and deadlocks.

Since the clock are already prepared since probe() and unprepared in remove() use simple clk_enable()/clk_disable() calls to enable and disable the clock on runtime suspend and resume to avoid hitting the prepare_lock mutex.

CVSS Vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Reference

https://git.kernel.org/stable/c/9b8bc33ad64192f54142396470cc34ce539a8940 https://git.kernel.org/stable/c/1883cad2cc629ded4a3556c0bbb8b42533ad8764 https://git.kernel.org/stable/c/c2024b1a583ab9176c797ea1e5f57baf8d5e2682 https://git.kernel.org/stable/c/22a1f8a5b56ba93d3e8b7a1dafa24e01c8bb48ba https://git.kernel.org/stable/c/fac3c9f7784e8184c0338e9f0877b81e55d3ef1c https://git.kernel.org/stable/c/894cd5f5fd9061983445bbd1fa3d81be43095344 https://git.kernel.org/stable/c/048bbbdbf85e5e00258dfb12f5e368f908801d7b

Attack Complexity

LOW

Privileges Required

LOW

User Interaction Required

LOW

Scope

NONE

Confidentiality Impact

UNCHANGED

Integrity Impact

NONE

Availability Impact

NONE

Base Score

HIGH

Base Severity

5.5