CVE-2024-38622

What it actually does

In dpu_core_irq_callback_handler a function pointer is compared to NULL yet unconditionally dereferenced and invoked, allowing a NULL pointer dereference or execution of an invalid address inside the kernel IRQ path.

Why it matters to the business

Kernel crashes on affected Linux systems can cause sudden loss of graphics, display, or entire system availability, requiring reboots and interrupting user workloads or services.

How an attack unfolds

An attacker with the ability to trigger or manipulate IRQ callbacks in the msm dpu driver (for example via crafted graphics operations or device interaction) supplies a NULL or invalid callback pointer; the missing conditional check lets the kernel dereference and jump to it, resulting in a crash that may be turned into denial of service or, in some contexts, further kernel memory corruption.

How to fix it

Apply the upstream fix present in commit 873f67699114452c2a996c4e10faac8ff860c241 or later; rebuild and deploy the updated kernel package for all affected distributions; test display and IRQ paths after upgrade.

How to confirm the fix worked

Confirm the running kernel contains commit 873f67699114452c2a996c4e10faac8ff860c241; review source for the added conditional return before the callback invocation; exercise display IRQ paths under load to verify stability.

Typical attack path

1. Identify a system running an unpatched Linux kernel with msm/dpu display driver enabled
2. Trigger graphics or display operations that reach dpu_core_irq_callback_handler
3. Supply or force a NULL callback pointer through driver state manipulation
4. Observe kernel panic or use the resulting corruption for privilege escalation or denial of service

How to detect it

Review kernel logs for NULL pointer dereference oops or panic messages originating from dpu_core_irq_callback_handler; correlate with recent display or graphics activity; examine crash dumps for instruction pointer values near the callback call site.

What your security team should do

• Prioritize kernel updates on all systems using the msm/dpu driver
• Monitor vendor advisories for distribution-specific backports of commit 873f67699114452c2a996c4e10faac8ff860c241
• Restrict untrusted graphics or display workloads until patches are applied
• Include the updated kernel in the next maintenance window for non-critical systems