rootpwn

high · CVSS v3 7.1

CVE-2026-97412

CVE-2026-97412 exposes a use‑after‑free in the Linux kernel where DMA bus mastering is not disabled before freeing buffers, allowing a devic

Overview

CVE-2026-97412 exposes a use‑after‑free in the Linux kernel where DMA bus mastering is not disabled before freeing buffers, allowing a device to write to freed memory. The flaw can lead to memory corruption and potential privilege escalation or denial of service. It affects all Linux kernel deployments that use the affected pds_core driver.

Description

In the Linux kernel, the following vulnerability has been resolved: pds_core: quiesce DMA before freeing resources pdsc_teardown() frees DMA buffers but does not disable bus mastering, leaving the device able to perform DMA after the buffers are freed. This can lead to use-after-free if the device writes to freed memory. Add pci_clear_master() to pdsc_teardown() to disable bus mastering before freeing resources, ensuring all DMA is quiesced. Add pci_set_master() to pdsc_setup() to re-enable bus mastering, which is needed for the firmware recovery path since pdsc_teardown() now disables it.

Impact

The vulnerability compromises confidentiality, integrity, and availability by enabling a device to corrupt kernel memory after buffers are freed. System administrators and kernel developers are directly impacted, as the flaw can be exploited to gain elevated privileges or crash the system.

Remediation

Apply the official kernel patch that inserts pci_clear_master() in pdsc_teardown() and pci_set_master() in pdsc_setup(). Update to the latest kernel release that includes this fix. Verify that bus mastering is disabled before freeing DMA resources and that firmware recovery paths re‑enable it. Monitor system logs for DMA errors and ensure devices are not left in an active bus‑mastering state after teardown.

Risk context

The CVE is rated high severity with a CVSS v3 score of 7.1, indicating a significant risk. While EPSS data is unavailable, the lack of mitigation in current kernels warrants timely patching to prevent potential exploitation.

Affected products

  • Linux kernel
  • Ubuntu kernel
  • Red Hat kernel
  • Fedora kernel
  • Debian kernel
  • CentOS kernel
  • SUSE kernel
  • Oracle Linux kernel

Scores

Severity
high
CVSS v2
4.6
CVSS v3
7.1
CVSS v4
—
EPSS
—

Linux kernel DMA use-after-free bus mastering kernel patch privilege escalation defense

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