CVE-2024-26952

What it actually does

Invalid buffer offset fields in ksmbd SMB requests allow out-of-bounds memory access when the offset is below the minimum buffer offset value.

Why it matters to the business

Local attackers on affected Linux systems can achieve full code execution or system crashes, risking data breaches and service disruption; high downstream kernel prevalence increases exposure across servers and embedded devices.

How an attack unfolds

An attacker with local access crafts SMB requests containing invalid buffer offset values targeting ksmbd, triggering out-of-bounds access that can be leveraged for privilege escalation or denial of service.

How to fix it

Upgrade the Linux kernel to commit 480469f145e5abf83361e608734e421b7d99693d or later stable releases containing the fix; rebuild and reboot systems using affected ksmbd-enabled kernels.

How to confirm the fix worked

Verify kernel version or git commit includes 480469f145e5abf83361e608734e421b7d99693d; test ksmbd request handling with offset validation enabled.

Typical attack path

1. Obtain local user access on target system
2. Identify ksmbd service exposure
3. Craft and send SMB request with invalid buffer offset
4. Trigger out-of-bounds memory operation
5. Escalate privileges or crash kernel

How to detect it

Review kernel logs for ksmbd buffer offset validation failures or oops messages; inspect audit logs for unusual SMB request patterns from local processes.

What your security team should do

• Prioritize kernel updates on all internet-facing or multi-user Linux systems within 30 days
• Disable ksmbd if SMB server functionality is not required
• Monitor for local privilege escalation attempts post-remediation
• Apply vendor backports where full kernel upgrade is delayed