CVE-2026-80810
Description
A flaw was found in the Linux kernel. An integer overflow vulnerability in the io_uring/rsrc component, specifically within the io_vec_fill_bvec() function, can lead to incorrect memory calculations when handling very large memory pages. This error causes the kernel to access memory outside of its intended boundaries, which could result in system instability or a denial of service. A local attacker could potentially leverage this to corrupt kernel memory.
Mitigation
Disable io_uring system-wide using sysctl to prevent creation and registration of io_uring buffers.
To apply this change immediately on running systems:
sh
sysctl -w kernel.io_uring_disabled=2
To persist this setting across system boots:
sh
echo "kernel.io_uring_disabled = 2" > /etc/sysctl.d/99-disable-io-uring.conf
Caveats:
Disabling io_uring will cause services and applications that depend on io_uring asynchronous I/O to fail or fall back to synchronous operations. Active processes with existing io_uring instances must be restarted for the restriction to take full effect. Systems running on x86_64 are not exposed, and on vulnerable architectures, avoiding the allocation of 16GB gigantic hugetlb pages also prevents exposure.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7 | N/A | N/A |
| Attack Vector | Local | N/A | N/A |
| Attack Complexity | High | N/A | N/A |
| Privileges Required | Low | N/A | N/A |
| User Interaction | None | N/A | N/A |
| Scope | Unchanged | N/A | N/A |
| Confidentiality | High | N/A | N/A |
| Integrity Impact | High | N/A | N/A |
| Availability Impact | High | N/A | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Integrity
Technical Impact: Modify Memory; Execute Unauthorized Code or Commands
Write operations could cause memory corruption. In some cases, an adversary can modify control data such as return addresses in order to execute unexpected code.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
Attempting to access out-of-range, invalid, or unauthorized memory could cause the product to crash.
Other
Technical Impact: Unexpected State
Subsequent write operations can produce undefined or unexpected results.
Frequently Asked Questions
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