CVE-2023-52494

What it actually does

Missing alignment validation on the MHI event ring read pointer allows an unaligned value (not 128-bit aligned to struct mhi_ring_element) to pass the existing buffer-range check, enabling out-of-bounds access that can corrupt ring-buffer memory or trigger a denial of service.

Why it matters to the business

Systems using MHI-based modems or similar hardware may experience kernel crashes or memory corruption, reducing availability of network or device-dependent services until the kernel is updated.

How an attack unfolds

An attacker who can influence the event ring read pointer (via local code execution, compromised driver, or malformed hardware responses) supplies an unaligned pointer value; when the ring-processing code dereferences it, the kernel either reads invalid memory or writes outside the intended buffer, resulting in corruption or a crash.

How to fix it

Upgrade the Linux kernel to a version containing commit 94991728c84f8df54fd9eec9b85855ef9057ea08 (or the equivalent stable back-port) so that the added alignment check for the event ring read pointer is present.

How to confirm the fix worked

Confirm the fix by inspecting the kernel source for the new alignment test after the existing is_valid_ring_ptr call, or verify the running kernel reports a build that includes the referenced commit hash.

Typical attack path

1. Obtain local execution or hardware control sufficient to set the MHI event ring read pointer
2. Write an unaligned pointer value that still lies inside the ring buffer range
3. Trigger MHI event ring processing (normal device activity or crafted stimulus)
4. Observe kernel memory corruption or panic

How to detect it

Examine kernel logs (dmesg, /var/log/kern.log) for MHI ring-related warnings, alignment faults, or unexpected panics; no public exploitation artifacts have been observed.

What your security team should do

• Prioritize kernel updates on all systems that use MHI host drivers
• Apply the patch or newer stable release within normal change windows after testing
• Review downstream distributions for back-ported fixes and schedule deployment accordingly