CVE-2024-26710

What it actually does

KASAN-enabled powerpc builds could exceed available stack space (leading to overflow on 32-bit systems) or trigger assembler operand-range errors when the stack was unconditionally doubled.

Why it matters to the business

Affected Linux kernels on powerpc hardware may become unstable or fail to compile when KASAN is active, disrupting embedded, server, or specialized workloads that rely on memory-safety instrumentation.

How an attack unfolds

An attacker with the ability to drive deep kernel call stacks on a vulnerable powerpc system with KASAN enabled can exhaust the limited stack, resulting in a kernel panic or memory corruption that may be leveraged for denial of service.

How to fix it

Upgrade the Linux kernel to version 6.1.76 or later, or apply commit f9a4c401bf4c5af3437ad221c0a5880a518068d4; rebuild with the corrected KASAN stack-size logic that only increases the stack when the base size is below 32 KB.

How to confirm the fix worked

Verify the running kernel version is 6.1.76 or newer; inspect powerpc Kconfig and switch.S to confirm the conditional 32 KB stack-size limit for KASAN is present and that the build completes without operand-range errors.

Typical attack path

1. Identify powerpc target running a KASAN-enabled kernel build
2. Trigger sequences of kernel functions that consume 2-3 KB or more of stack
3. Force stack overflow leading to panic or corruption

How to detect it

Review kernel crash logs and panics on powerpc systems for stack-overflow signatures; correlate with KASAN build configurations and recent changes to thread stack size.

What your security team should do

• Prioritize patching production powerpc systems to 6.1.76 or newer
• Audit any custom KASAN-enabled kernel builds for the unconditional doubling change
• Consider disabling KASAN on 32-bit powerpc targets where memory-safety checks are not required