Linux Kernel up to 6.8.9 task_mmu make_uffd_wp_pte denial of service

Summaryinfo

A vulnerability marked as problematic has been reported in Linux Kernel up to 6.8.9. The affected element is the function make_uffd_wp_pte of the component task_mmu. Performing a manipulation results in denial of service. This vulnerability was named CVE-2024-36943. There is no available exploit. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.8.9. It has been classified as problematic. This affects the function make_uffd_wp_pte of the component task_mmu. The manipulation with an unknown input leads to a denial of service vulnerability. CWE is classifying the issue as CWE-404. The product does not release or incorrectly releases a resource before it is made available for re-use. This is going to have an impact on availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: fs/proc/task_mmu: fix loss of young/dirty bits during pagemap scan make_uffd_wp_pte() was previously doing: pte = ptep_get(ptep); ptep_modify_prot_start(ptep); pte = pte_mkuffd_wp(pte); ptep_modify_prot_commit(ptep, pte); But if another thread accessed or dirtied the pte between the first 2 calls, this could lead to loss of that information. Since ptep_modify_prot_start() gets and clears atomically, the following is the correct pattern and prevents any possible race. Any access after the first call would see an invalid pte and cause a fault: pte = ptep_modify_prot_start(ptep); pte = pte_mkuffd_wp(pte); ptep_modify_prot_commit(ptep, pte);

The advisory is shared at git.kernel.org. This vulnerability is uniquely identified as CVE-2024-36943. The exploitability is told to be difficult. Technical details are known, but no exploit is available.

Upgrading to version 6.8.10 eliminates this vulnerability. Applying the patch 74b3d66f91d9/c70dce4982ce 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.

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Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 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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