CVE-2024-35940

What it actually does

Missing null pointer check after kasprintf() in pstore/zone psz_kmsg_read allows NULL dereference on allocation failure, resulting in kernel crash or panic.

Why it matters to the business

Linux systems may experience unexpected crashes and loss of availability when reading persistent kernel logs under memory pressure; low EPSS and no KEV status indicate limited active exploitation risk but patching remains necessary for stability.

How an attack unfolds

An attacker with local access triggers low-memory conditions during pstore kmsg read to force kasprintf failure, leading to NULL dereference and denial of service; listed Android kernel threat actor context does not align with this local memory issue.

How to fix it

Update the Linux kernel to commit 98e2b97acb875d65bdfc75fc408e67975cef3041 or equivalent fixed version in the stable tree; apply the patch that adds the null pointer check after kasprintf.

How to confirm the fix worked

Inspect the psz_kmsg_read function in pstore/zone.c for the added NULL check on the kasprintf result after applying the update; confirm kernel builds and boots without regression in pstore functionality.

Typical attack path

1. Obtain local user access on affected Linux kernel
2. Induce memory pressure to cause kasprintf failure in pstore zone
3. Invoke psz_kmsg_read path to trigger NULL dereference and kernel panic

How to detect it

Search kernel logs and crash dumps for oops/panic entries referencing pstore, zone, or kmsg_read functions around unexpected reboots; monitor for allocation failure patterns preceding the crash.

What your security team should do

• Prioritize kernel updates on all affected systems within standard maintenance windows given low exploit maturity
• Test the fixed kernel in staging environments before broad deployment
• Review pstore usage and consider disabling if not required to reduce attack surface