CVE-2024-49985

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> i2c: stm32f7: Do not prepare/unprepare clock during runtime suspend/resume<br /> <br /> In case there is any sort of clock controller attached to this I2C bus<br /> controller, for example Versaclock or even an AIC32x4 I2C codec, then<br /> an I2C transfer triggered from the clock controller clk_ops .prepare<br /> callback may trigger a deadlock on drivers/clk/clk.c prepare_lock mutex.<br /> <br /> This is because the clock controller first grabs the prepare_lock mutex<br /> and then performs the prepare operation, including its I2C access. The<br /> I2C access resumes this I2C bus controller via .runtime_resume callback,<br /> which calls clk_prepare_enable(), which attempts to grab the prepare_lock<br /> mutex again and deadlocks.<br /> <br /> Since the clock are already prepared since probe() and unprepared in<br /> remove(), use simple clk_enable()/clk_disable() calls to enable and<br /> disable the clock on runtime suspend and resume, to avoid hitting the<br /> prepare_lock mutex.