CVE-2024-42096

What it actually does

The flaw in x86 profile_pc() performs unsafe direct reads from the stack pointer under invalid assumptions about spinlock stack frames (no frame or PUSHF eflags copy), leading to invalid memory accesses and KASAN warnings classified as memory corruption.

Why it matters to the business

Can trigger kernel instability or crashes during timer-based profiling on affected Linux systems, reducing availability in development, testing, or specialized production workloads. Low operational urgency due to stable low EPSS, no KEV listing, and removal of the code path.

How an attack unfolds

A local attacker enables timer profiling and exercises spinlock paths to trigger the faulty stack-layout assumptions in profile_pc(); listed threat actors associated with Linux kernel memory issues could leverage similar conditions, though exploitation maturity remains none.

How to fix it

Upgrade the Linux kernel to the fixed commit 65ebdde16e7f5da99dbf8a548fb635837d78384e (or equivalent stable release containing the removal of profile_pc stack games).

How to confirm the fix worked

Confirm the commit 65ebdde16e7f5da99dbf8a548fb635837d78384e is present in the kernel source or git history; recompile and test that profile_pc no longer contains the stack-pointer dereference logic.

Typical attack path

1. Gain local user access on x86 Linux
2. Enable or trigger timer-based kernel profiling
3. Exercise spinlock code paths to hit invalid stack reads
4. Induce KASAN-detected memory corruption or crash

How to detect it

Review kernel logs and KASAN reports for warnings or crashes referencing profile_pc and stack pointer accesses during profiling; correlate with timer interrupt activity.

• profile_pc
• KASAN: profile_pc
• stack games in profile_pc

What your security team should do

• Apply the kernel update containing commit 65ebdde16e7f5da99dbf8a548fb635837d78384e across all affected systems
• Monitor KASAN reports for profile_pc references until patched
• Disable timer profiling where feasible to reduce exposure