Description

In the Linux kernel, the following vulnerability has been resolved: phy: qcom-qusb2: Fix NULL pointer dereference on early suspend Enabling runtime PM before attaching the QPHY instance as driver data can lead to a NULL pointer dereference in runtime PM callbacks that expect valid driver data. There is a small window where the suspend callback may run after PM runtime enabling and before runtime forbid. This causes a sporadic crash during boot: ``` Unable to handle kernel NULL pointer dereference at virtual address 00000000000000a1 [...] CPU: 0 UID: 0 PID: 11 Comm: kworker/0:1 Not tainted 6.16.7+ #116 PREEMPT Workqueue: pm pm_runtime_work pstate: 20000005 (nzCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : qusb2_phy_runtime_suspend+0x14/0x1e0 [phy_qcom_qusb2] lr : pm_generic_runtime_suspend+0x2c/0x44 [...] ``` Attach the QPHY instance as driver data before enabling runtime PM to prevent NULL pointer dereference in runtime PM callbacks. Reorder pm_runtime_enable() and pm_runtime_forbid() to prevent a short window where an unnecessary runtime suspend can occur. Use the devres-managed version to ensure PM runtime is symmetrically disabled during driver removal for proper cleanup.

References 4

• git.kernel.org https://git.kernel.org/stable/c/1ca52c0983c34fca506921791202ed5bdafd5306
• git.kernel.org https://git.kernel.org/stable/c/4ac15caa27ff842b068a54f1c6a8ff8b31f658e7
• git.kernel.org https://git.kernel.org/stable/c/beba460a299150b5d8dcbe3474a8f4bdf0205180
• git.kernel.org https://git.kernel.org/stable/c/d50a9b7fd07296a1ab81c49ceba14cae3d31df86

Remediation