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Medium severity5.5NVD Advisory· Published May 30, 2024· Updated May 12, 2026

CVE-2024-36020

CVE-2024-36020

Description

In the Linux kernel, the following vulnerability has been resolved:

i40e: fix vf may be used uninitialized in this function warning

To fix the regression introduced by commit 52424f974bc5, which causes servers hang in very hard to reproduce conditions with resets races. Using two sources for the information is the root cause. In this function before the fix bumping v didn't mean bumping vf pointer. But the code used this variables interchangeably, so stale vf could point to different/not intended vf.

Remove redundant "v" variable and iterate via single VF pointer across whole function instead to guarantee VF pointer validity.

AI Insight

LLM-synthesized narrative grounded in this CVE's description and references.

A use-uninitialized variable in the Linux kernel i40e driver could cause hangs during VF reset races; fixed by using a single VF pointer.

Vulnerability

Overview

CVE-2024-36020 is a medium-severity vulnerability in the Linux kernel's i40e network driver, specifically in the handling of Virtual Function (VF) operations. The issue was introduced by commit 52424f974bc5, which led to a regression where servers could hang under very hard-to-reproduce conditions involving reset races. The root cause is that the code used two sources of information (v and vf variables) interchangeably, but bumping the v variable did not necessarily correspond to a valid vf pointer. This could cause stale vf pointers to point to a different or unintended VF, leading to undefined behavior.

Exploitation

Conditions

Exploitation requires an attacker to be able to trigger reset races on the i40e device, which typically involves having local access to the system or being able to manipulate VF state from a guest VM. No authentication is needed if the attacker can orchestrate the reset conditions, but this is generally limited to scenarios where they control a VF or the network interface. The race condition is difficult to trigger reliably, but when it occurs, it can cause system hangs.

Impact

If successfully triggered, the vulnerability can cause the server to hang, resulting in a denial of service (DoS). The CVSS v3 score of 5.5 (Medium) reflects the availability impact, though exploitation requires specific conditions and local access or control of VFs. No privilege escalation or data leakage is reported.

Mitigation

The fix removes the redundant v variable and iterates using a single VF pointer across the entire function, ensuring pointer validity is maintained. The patch has been applied to the Linux kernel stable branches, as seen in references [2], [3], and [4]. Users should update their kernels to incorporate the fix. Siemens also lists this CVE as affecting the SIMATIC S7-1500 TM MFP - GNU/Linux subsystem in their advisory [1], recommending appropriate remediation.

References
  1. SSA-265688
  2. Making sure you're not a bot!
  3. Making sure you're not a bot!
  4. Making sure you're not a bot!

AI Insight generated on May 20, 2026. Synthesized from this CVE's description and the cited reference URLs; citations are validated against the source bundle.

Affected products

161

Patches

0

No patches discovered yet.

Vulnerability mechanics

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References

11

News mentions

0

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