Linux Kernel up to 5.18.7 filemap_get_read_batch null pointer dereference

Summaryinfo

A vulnerability marked as problematic has been reported in Linux Kernel up to 5.18.7. This impacts the function filemap_get_read_batch. Performing a manipulation results in null pointer dereference. This vulnerability was named CVE-2022-49699. There is no available exploit. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as problematic, was found in Linux Kernel up to 5.18.7. This affects the function filemap_get_read_batch. The manipulation with an unknown input leads to a null pointer dereference vulnerability. CWE is classifying the issue as CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. This is going to have an impact on availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: filemap: Handle sibling entries in filemap_get_read_batch() If a read races with an invalidation followed by another read, it is possible for a folio to be replaced with a higher-order folio. If that happens, we'll see a sibling entry for the new folio in the next iteration of the loop. This manifests as a NULL pointer dereference while holding the RCU read lock. Handle this by simply returning. The next call will find the new folio and handle it correctly. The other ways of handling this rare race are more complex and it's just not worth it.

The advisory is shared at git.kernel.org. This vulnerability is uniquely identified as CVE-2022-49699 since 02/26/2025. The exploitability is told to be difficult. Technical details are known, but no exploit is available.

Upgrading to version 5.18.8 eliminates this vulnerability. Applying the patch a66f131d30e53000f08301776bf85c912ef47aad/cb995f4eeba9d268fd4b56c2423ad6c1d1ea1b82 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

• 5.18.0
• 5.18.1
• 5.18.2
• 5.18.3
• 5.18.4
• 5.18.5
• 5.18.6
• 5.18.7

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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CPE 2.2info

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Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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