CVE-2026-98801
Description
A flaw was found in the Linux kernel. A local user can cause a Denial of Service (DoS) or kernel memory corruption by manipulating socket memory reservation settings. Due to a lack of upper-bound validation and missing locking mechanisms when applied to User Datagram Protocol (UDP) sockets, integer overflows and race conditions can corrupt internal memory accounting. This flaw compromises system stability and may lead to a kernel crash.
Statement
SO_RESERVE_MEM can corrupt socket and memcg memory accounting through two related flaws. UDP receive and release paths protect sk_forward_alloc with sk_receive_queue.lock, while reservation updates use lock_sock, allowing concurrent operations to race and produce inconsistent accounting. Values near INT_MAX can also overflow sk_mem_pages(delta) and pages shifted by PAGE_SHIFT, corrupting sk_forward_alloc and sk_reserved_mem even without the UDP race. For the CVSS the PR:L value is used because a local process can create a socket and invoke setsockopt without requiring full administrative control. Remote UDP traffic may help exercise the race, but remote packets alone cannot invoke SO_RESERVE_MEM, so the issue is local rather than network reachable. The demonstrated impact is incorrect socket and memcg accounting with possible resource exhaustion or service disruption. A direct UAF, OOB access, arbitrary write, or reliable privilege escalation primitive is not established.
Mitigation
Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
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 | 5.5 | N/A | N/A |
| Attack Vector | Local | N/A | N/A |
| Attack Complexity | Low | 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 | None | N/A | N/A |
| Integrity Impact | None | N/A | N/A |
| Availability Impact | High | N/A | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Crash, Exit, or Restart; DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory); DoS: Resource Consumption (Other)
If an attacker can trigger the allocation of the limited resources, but the number or size of the resources is not controlled, then the most common result is denial of service. This would prevent valid users from accessing the product, and it could potentially have an impact on the surrounding environment, i.e., the product may slow down, crash due to unhandled errors, or lock out legitimate users. For example, a memory exhaustion attack against an application could slow down the application as well as its host operating system.
Access Control,Other
Technical Impact: Bypass Protection Mechanism; Other
In some cases it may be possible to force the product to "fail open" in the event of resource exhaustion. The state of the product -- and possibly the security functionality - may then be compromised.
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