CVE-2024-50091

What it actually does

Use-after-free in dm-vdo due to dereferencing a dedupe_context pointer after ownership is released without clearing the reference.

Why it matters to the business

Linux systems using VDO storage may experience kernel instability, crashes, or potential code execution that disrupts operations and requires urgent patching across fleets.

How an attack unfolds

An attacker triggers VDO deduplication paths to cause the context release, then forces subsequent code paths to examine the now-freed pointer, enabling memory corruption or control-flow hijacking.

How to fix it

Upgrade the Linux kernel to a version containing commit 63ef073084c67878d7a92e15ad055172da3f05a3 or later; rebuild and reboot affected systems.

How to confirm the fix worked

Confirm kernel source contains the pointer-clearing change; run VDO stress tests and verify absence of use-after-free warnings in kernel logs.

Typical attack path

1. Gain local access or trigger VDO workloads on target kernel
2. Induce dedupe_context allocation and release sequence
3. Reference the stale pointer via data_vio operations
4. Leverage resulting memory state for privilege escalation or denial of service

How to detect it

Search kernel logs for dm-vdo related oops, use-after-free warnings, or data_vio dereference faults; correlate with VDO deduplication activity spikes.

What your security team should do

• Prioritize kernel upgrades on all systems exposing VDO volumes
• Review and apply stable kernel updates containing the referenced commit
• Limit untrusted local access until patches are deployed
• Monitor kernel update channels for backports to distribution kernels