Linux Kernel up to 6.6.50/6.10.9 userfaultfd privilege escalation

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.6.50/6.10.9. It has been rated as problematic. Affected by this issue is some unknown functionality of the component userfaultfd. This manipulation causes an unknown weakness. The identification of this vulnerability is CVE-2024-46838. There is no exploit available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.6.50/6.10.9. It has been declared as problematic. Affected by this vulnerability is an unknown function of the component userfaultfd. The impact remains unknown. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: userfaultfd: don't BUG_ON() if khugepaged yanks our page table Since khugepaged was changed to allow retracting page tables in file mappings without holding the mmap lock, these BUG_ON()s are wrong - get rid of them. We could also remove the preceding "if (unlikely(...))" block, but then we could reach pte_offset_map_lock() with transhuge pages not just for file mappings but also for anonymous mappings - which would probably be fine but I think is not necessarily expected.

It is possible to read the advisory at git.kernel.org. This vulnerability is known as CVE-2024-46838 since 09/11/2024. The technical details are unknown and an exploit is not publicly available.

The vulnerability scanner Nessus provides a plugin with the ID 212724 (Ubuntu 22.04 LTS / 24.04 LTS : Linux kernel vulnerabilities (USN-7154-1)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.6.51 or 6.10.10 eliminates this vulnerability. Applying the patch 4a594acc12d5/db978287e908/4828d207dc51 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 databases at Tenable (212724) and CERT Bund (WID-SEC-2024-3050). Be aware that VulDB is the high quality source for vulnerability data.

Affected

• Google Container-Optimized OS
• Debian Linux
• Amazon Linux 2
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• Kyocera Printer
• RESF Rocky Linux
• Broadcom Brocade SANnav
• Open Source Linux Kernel
• IBM QRadar SIEM
• 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
• 6.6.31
• 6.6.32
• 6.6.33
• 6.6.34
• 6.6.35
• 6.6.36
• 6.6.37
• 6.6.38
• 6.6.39
• 6.6.40
• 6.6.41
• 6.6.42
• 6.6.43
• 6.6.44
• 6.6.45
• 6.6.46
• 6.6.47
• 6.6.48
• 6.6.49
• 6.6.50
• 6.10.0
• 6.10.1
• 6.10.2
• 6.10.3
• 6.10.4
• 6.10.5
• 6.10.6
• 6.10.7
• 6.10.8
• 6.10.9

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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CPE 2.2info

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CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

Be aware that VulDB is the high quality source for vulnerability data.

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