CVE-2026-31493: RDMA/efa: Fix use of completion ctx after free
In the Linux kernel, the following vulnerability has been resolved:
RDMA/efa: Fix use of completion ctx after free
On admin queue completion handling, if the admin command completed with error we print data from the completion context. The issue is that we already freed the completion context in polling/interrupts handler which means we print data from context in an unknown state (it might be already used again). Change the admin submission flow so alloc/dealloc of the context will be symmetric and dealloc will be called after any potential use of the context.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
ubuntu/linux-nvidia-tegrato a version that resolves this vulnerability.Fixed in 6.8.0-1035.38 - Compensating control
Change the RDMA/efa admin submission flow so completion-context allocation and deallocation are symmetric, and defer deallocation until after all potential uses of the context, including printing completion data when an admin command completes with an error.
Event History
Frequently Asked Questions
What is the severity of CVE-2026-31493?
CVE-2026-31493 is classified as a medium severity vulnerability due to the risk of information exposure.
How do I fix CVE-2026-31493?
To fix CVE-2026-31493, update to the latest version of the Linux kernel where this vulnerability has been patched.
What type of vulnerability is CVE-2026-31493?
CVE-2026-31493 is a memory corruption vulnerability that involves the improper handling of completion contexts after they have been freed.
Who is affected by CVE-2026-31493?
CVE-2026-31493 affects users and systems running vulnerable versions of the Linux kernel that utilize RDMA functionality.
What is the impact of CVE-2026-31493?
The impact of CVE-2026-31493 includes potential information leaks and undefined behaviors that could lead to system instability.