Linux Kernel up to 6.6.30/6.8.9 userfaultfd close memory corruption

Summaryinfo

A vulnerability, which was classified as critical, was found in Linux Kernel up to 6.6.30/6.8.9. Affected by this vulnerability is the function close of the component userfaultfd. Such manipulation leads to memory corruption. This vulnerability is listed as CVE-2024-36881. There is no available exploit. You should upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as critical, has been found in Linux Kernel up to 6.6.30/6.8.9. Affected by this issue is the function close of the component userfaultfd. The manipulation with an unknown input leads to a memory corruption vulnerability. Using CWE to declare the problem leads to CWE-119. The product performs operations on a memory buffer, but it can read from or write to a memory location that is outside of the intended boundary of the buffer. Impacted is confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: mm/userfaultfd: reset ptes when close() for wr-protected ones Userfaultfd unregister includes a step to remove wr-protect bits from all the relevant pgtable entries, but that only covered an explicit UFFDIO_UNREGISTER ioctl, not a close() on the userfaultfd itself. Cover that too. This fixes a WARN trace. The only user visible side effect is the user can observe leftover wr-protect bits even if the user close()ed on an userfaultfd when releasing the last reference of it. However hopefully that should be harmless, and nothing bad should happen even if so. This change is now more important after the recent page-table-check patch we merged in mm-unstable (446dd9ad37d0 ("mm/page_table_check: support userfault wr-protect entries")), as we'll do sanity check on uffd-wp bits without vma context. So it's better if we can 100% guarantee no uffd-wp bit leftovers, to make sure each report will be valid.

The advisory is available at git.kernel.org. This vulnerability is handled as CVE-2024-36881. The exploitation is known to be easy. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 08/28/2025).

Upgrading to version 6.6.31 or 6.8.10 eliminates this vulnerability. Applying the patch 377f3a9a3d03/8d8b68a5b0c9/c88033efe9a3 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at CERT Bund (WID-SEC-2024-1259). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Affected

• Debian Linux
• Amazon Linux 2
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• IBM InfoSphere Guardium
• Oracle Linux
• Oracle VM
• NetApp FAS
• EMC Avamar
• NetApp AFF
• Dell NetWorker
• NetApp ActiveIQ Unified Manager
• IBM Security Guardium
• RESF Rocky Linux
• Broadcom Brocade SANnav
• Open Source Linux Kernel
• IBM Business Automation Workflow
• IBM QRadar SIEM
• Dell Avamar
• IBM Storage Scale
• IBM Spectrum Protect Plus
• Juniper Junos Space
• IBM Storage Scale System
• SolarWinds Security Event Manager

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.6.0
• 6.6.1
• 6.6.2
• 6.6.3
• 6.6.4
• 6.6.5
• 6.6.6
• 6.6.7
• 6.6.8
• 6.6.9
• 6.6.10
• 6.6.11
• 6.6.12
• 6.6.13
• 6.6.14
• 6.6.15
• 6.6.16
• 6.6.17
• 6.6.18
• 6.6.19
• 6.6.20
• 6.6.21
• 6.6.22
• 6.6.23
• 6.6.24
• 6.6.25
• 6.6.26
• 6.6.27
• 6.6.28
• 6.6.29
• 6.6.30
• 6.8.0
• 6.8.1
• 6.8.2
• 6.8.3
• 6.8.4
• 6.8.5
• 6.8.6
• 6.8.7
• 6.8.8
• 6.8.9

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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CPE 2.2info

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CVSSv4info

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Exploitinginfo

Threat Intelligenceinfo

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Timelineinfo

Sourcesinfo

Entryinfo

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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