CVE-2024-27039

What it actually does

Incorrect pointer arithmetic on an array allocated for clock registration in the hi3559a driver can cause devm_kfree to release the wrong memory region when a clk_register call fails, resulting in memory corruption or use-after-free conditions within the Linux kernel.

Why it matters to the business

Systems using affected HiSilicon hardware may experience kernel instability or crashes that interrupt services and require reboots, with higher urgency on devices running older kernel versions from the stable tree.

How an attack unfolds

An attacker able to induce clk_register failures in the hi3559a clock initialization path can trigger the erroneous free, corrupting kernel memory structures that may be further leveraged to achieve local privilege escalation or denial of service.

How to fix it

Apply the kernel fix present in commit 3f8445f1c746fda180a7f75372ed06b24e9cefe2; rebuild and deploy updated kernels containing the corrected devm_kfree logic for the hi3559a driver.

How to confirm the fix worked

Confirm the fix by inspecting kernel source for proper pointer handling before the devm_kfree call or by verifying the commit hash is included in the deployed kernel tree.

Typical attack path

1. Gain local access on a hi3559a-based Linux system
2. Trigger conditions that cause clk_register to fail during driver initialization
3. Force the incremented p_clk pointer to reference incorrect memory for deallocation
4. Exploit resulting memory corruption for privilege escalation or system crash

How to detect it

Review kernel logs and oops traces for references to hi3559a clk registration failures or erroneous memory frees involving p_clk; correlate with boot-time driver initialization events.

What your security team should do

• Update affected kernels to the fixed commit on all hi3559a hardware as soon as possible
• Test updated kernels in non-production environments before broad rollout
• Monitor kernel logs for clock driver initialization errors or memory fault traces