Linux Kernel up to 6.18.26/7.0.3 mmap_prepare reference count

Summaryinfo

A vulnerability described as critical has been identified in Linux Kernel up to 6.18.26/7.0.3. Affected by this vulnerability is the function mmap_prepare. Executing a manipulation can lead to reference count. This vulnerability is tracked as CVE-2026-46100. No exploit exists. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability has been found in Linux Kernel up to 6.18.26/7.0.3 and classified as critical. This vulnerability affects the function mmap_prepare. The manipulation with an unknown input leads to a reference count vulnerability. The CWE definition for the vulnerability is CWE-911. The product uses a reference count to manage a resource, but it does not update or incorrectly updates the reference count. As an impact it is known to affect availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: fs: afs: revert mmap_prepare() change Partially reverts commit 9d5403b1036c ("fs: convert most other generic_file_*mmap() users to .mmap_prepare()"). This is because the .mmap invocation establishes a refcount, but .mmap_prepare is called at a point where a merge or an allocation failure might happen after the call, which would leak the refcount increment. Functionality is being added to permit the use of .mmap_prepare in this case, but in the interim, we need to fix this.

The advisory is available at git.kernel.org. This vulnerability was named CVE-2026-46100 since 05/13/2026. Technical details are known, but there is no available exploit.

Upgrading to version 6.18.27, 7.0.4 or 7.1-rc1 eliminates this vulnerability. Applying the patch f51f85c044809fbd39ac8ae07ac99bc43ce32bd5/48c7a0eaeea41da17d1d84d2d7a4c40be122b246/fbfc6578eaca12daa0c09df1e9ba7f2c657b49da 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.

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

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.18.0
• 6.18.1
• 6.18.2
• 6.18.3
• 6.18.4
• 6.18.5
• 6.18.6
• 6.18.7
• 6.18.8
• 6.18.9
• 6.18.10
• 6.18.11
• 6.18.12
• 6.18.13
• 6.18.14
• 6.18.15
• 6.18.16
• 6.18.17
• 6.18.18
• 6.18.19
• 6.18.20
• 6.18.21
• 6.18.22
• 6.18.23
• 6.18.24
• 6.18.25
• 6.18.26
• 7.0.0
• 7.0.1
• 7.0.2
• 7.0.3

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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Entryinfo

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