Cloudanix VulnDB

CVE-2026-92514

None

CVSS

—

EPSS

0.2%

Published

Sep 17, 2026

CISA due date

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Cloudanix analysis

Schedule a fix SSVC: Track

A flaw in a Linux network driver can let an attacker who already has access to the machine crash the system or gain higher privileges when certain hardware components are removed or reset.

Exploitation
Local Privilege
Attacker needs
Local User
Complexity
Moderate
Impact
Privilege Gain
Component
OS kernel
Class
Use After Free
Remediation
Upgrade
Effort
Medium
Patch risk
Low

What it actually does

Use-after-free occurs when a scheduled tasklet continues to access DMA-coherent EQ ring buffers and doorbell records after erdma_ceqs_uninit frees the IRQ and destroys the EQ structures, because free_irq does not synchronize with already-queued tasklets.

Why it matters to the business

Systems using the erdma RDMA driver can experience kernel crashes, memory corruption, or potential local privilege escalation during driver unload or device removal events, disrupting high-performance networking workloads and requiring urgent patching on affected Linux kernels.

How an attack unfolds

An attacker with local access triggers repeated load/unload cycles or hardware removal events on the erdma device while a completion event is being processed; the tasklet scheduled by the interrupt handler then dereferences freed memory, allowing control of kernel execution flow if the freed objects are reallocated with attacker-controlled data.

How to fix it

Update to a Linux kernel containing the fix that kills the tasklet after free_irq and before EQ buffer release; apply the patch from the RDMA/erdma commit that resolves the CEQ tasklet use-after-free.

How to confirm the fix worked

Confirm the presence of the upstream fix in erdma_ceqs_uninit that calls tasklet_kill after free_irq; test by exercising module unload under interrupt load and verify no use-after-free reports in kernel logs or KASAN output.

Typical attack path

  1. Obtain local unprivileged access on a system with the erdma RDMA driver loaded
  2. Trigger device removal or module unload while completion events are active
  3. Race the tasklet execution against erdma_eq_destroy to access freed qbuf and dbrec structures
  4. Reallocate the freed memory with controlled content to corrupt kernel state or redirect execution

How to detect it

Review kernel logs for use-after-free warnings or oops traces referencing erdma_ceq_completion_handler, erdma_eq_destroy, or CEQ tasklet activity during module unload; correlate with audit logs showing erdma module removal or device hot-unplug events.

What your security team should do

  • Prioritize kernel updates on all systems exposing the erdma driver, especially those handling RDMA traffic
  • Restrict unprivileged local access and module loading until patched
  • Monitor for kernel oops or panic events during driver lifecycle operations

The record

In the Linux kernel, the following vulnerability has been resolved: RDMA/erdma: Fix CEQ tasklet use-after-free on removal Each CEQ interrupt handler only schedules eqc->tasklet. The tasklet calls erdma_ceq_completion_handler(), which reads the DMA-coherent EQ ring through get_next_valid_eqe() and updates eq->dbrec through notify_eq(). erdma_ceqs_uninit() frees each CEQ IRQ and then destroys its EQ. free_irq() prevents another hard IRQ and waits for an in-flight handler, but it does not drain a tasklet that the handler already scheduled. The tasklet can therefore access eq->qbuf or eq->dbrec after erdma_eq_destroy() frees them. Clearing ceq_cb->ready does not synchronize with a tasklet that already passed the check at the start of erdma_ceq_completion_handler(). Kill the tasklet after free_irq(), when no handler can schedule it again, and before erdma_ceq_uninit_one() releases the EQ buffers.

Affected packages

Ecosystem Package Introduced Fixed