CVE-2024-50260

What it actually does

A NULL pointer dereference in sock_map_link_update_prog() triggered by a race condition where sockmap_link->map is set to NULL during link detachment while an update attempts sock_map_prog_link_lookup.

Why it matters to the business

Can cause kernel crashes leading to system instability, reboots, or denial of service on affected Linux systems with low exploit likelihood.

How an attack unfolds

An attacker with local access triggers concurrent sock_map_link_detach and sock_map_link_update_prog calls protected by sockmap_mutex, causing the map pointer to become NULL when looked up during the race.

How to fix it

Apply the upstream kernel patch adding a NULL pointer check in sock_map_link_update_prog() and update to a fixed kernel version; for the listed flashplugin-nonfree package on Ubuntu 14.04 LTS use version 11.2.202.535ubuntu0.14.04.1.

How to confirm the fix worked

Confirm updated kernel or package version, review source for the added NULL check, and test concurrent link detach/update operations for stability.

Typical attack path

1. Gain local access to a vulnerable Linux system
2. Identify and target sockmap link operations
3. Trigger concurrent detach and update operations under the mutex
4. Force NULL pointer dereference leading to kernel panic

How to detect it

Review kernel logs and dmesg for NULL dereference oops involving sock_map_link_update_prog or sockmap functions; no widespread exploitation reported.

What your security team should do

• Prioritize kernel updates on exposed systems despite low EPSS
• Monitor system logs for related kernel oops or panics
• Restrict untrusted local code execution where possible