CVE-2023-52495

What it actually does

Incomplete port index validation in the Qualcomm PMIC GLINK altmode driver allows a notification for an unsupported port number to index beyond the two-element port array, resulting in out-of-bounds memory read/write and potential kernel memory corruption.

Why it matters to the business

Systems running affected Linux kernels on Qualcomm platforms may experience unexpected crashes, memory corruption, or loss of USB/altmode functionality, increasing downtime and operational risk on embedded and mobile devices until kernels are updated.

How an attack unfolds

An attacker with the ability to inject or trigger PMIC GLINK notifications (via compromised firmware, hardware manipulation, or a local process) supplies a port index greater than one; the missing bounds check then permits access outside the allocated port array, enabling memory corruption that can be leveraged for denial of service or, with further effort, privilege escalation.

How to fix it

Update to a Linux kernel containing commit 532a5557da6892a6b2d5793052e1bce1f4c9e177 or later; rebuild and deploy the updated kernel on all affected Qualcomm-based devices; apply vendor-supplied kernel packages as soon as they become available.

How to confirm the fix worked

Confirm the running kernel source contains commit 532a5557da6892a6b2d5793052e1bce1f4c9e177; verify the port sanity check now rejects indices outside 0-1 before any array access; test with synthetic notifications that previously triggered the flaw.

Typical attack path

1. Obtain local access or control over PMIC GLINK notification path on target Qualcomm-based system
2. Craft and deliver a notification referencing port index >= 2
3. Driver performs unchecked array access leading to out-of-bounds memory operation
4. Corrupt adjacent kernel structures to achieve denial of service or escalate privileges

How to detect it

Review kernel logs for oops or panic messages referencing pmic_glink_altmode or port array access; examine dmesg and syslog around the time of any unexplained crashes on Qualcomm platforms for signs of invalid port notifications.

What your security team should do

• Prioritize kernel updates on all Qualcomm-based Linux systems within the next patching cycle
• Monitor vendor advisories for backported fixes in supported LTS branches
• Restrict untrusted local code execution on embedded devices until patched
• Include the updated commit hash in SBOM and kernel configuration validation