CVE-2026-93154
Description
A flaw was found in the Linux kernel's RDMA/irdma component. This vulnerability allows a local user to deregister Memory Regions (MRs) that are actively backing Queue Pair (QP), Completion Queue (CQ), and Shared Receive Queue (SRQ) rings. By doing so, a malicious user could potentially disrupt network communication or cause system instability, leading to a denial of service.
Statement
The irdma driver did not pin the lifetime of user MRs that back QP/CQ/SRQ ring objects. A local process with access to RDMA uverbs could associate an MR with a user ring and then deregister that MR while the QP CQ or SRQ object still kept references to the backing PBL or MR state. This creates a use-after-free candidate rather than a simple resource leak, because later destroy resize or queue handling paths may touch memory whose owning MR lifetime has ended. For the CVSS the PR:L is used because reliable triggering requires local code execution with access to the RDMA uverbs device, but it does not require full administrator privileges in systems where RDMA access is delegated to users or service accounts. The issue is not directly network reachable because a remote peer cannot deregister the local MR by itself. Impact is at least local denial of service via kernel crash and in the paranoid case may include confidentiality and integrity impact due to possible memory corruption or privilege escalation.
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 | 7.8 |
| Attack Vector | Local | N/A | Local |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | Low | N/A | Low |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | None | N/A | High |
| Integrity Impact | None | N/A | High |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
cve.org: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Integrity
Technical Impact: Modify Memory
The use of previously freed memory may corrupt valid data, if the memory area in question has been allocated and used properly elsewhere.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
If chunk consolidation occurs after the use of previously freed data, the process may crash when invalid data is used as chunk information.
Confidentiality
Technical Impact: Read Memory
Read operations on freed memory can sometimes leak sensitive information instead of causing a crash
Integrity,Confidentiality,Availability
Technical Impact: Execute Unauthorized Code or Commands
If malicious data is entered before chunk consolidation can take place, it may be possible to take advantage of a write-what-where primitive to execute arbitrary code. If the newly allocated data happens to hold a class, in C++ for example, various function pointers may be scattered within the heap data. If one of these function pointers is overwritten with an address to valid shellcode, execution of arbitrary code can be achieved.
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