Linux Kernel raid1/raid10 md_cloned_bio out-of-bounds write

Summaryinfo

A vulnerability identified as very critical has been detected in Linux Kernel. Impacted is the function md_cloned_bio of the component raid1/raid10. The manipulation leads to out-of-bounds write. This vulnerability is traded as CVE-2026-74373. An attack has to be approached locally. There is no exploit available.

Detailsinfo

A vulnerability was found in Linux Kernel (affected version not known). It has been rated as very critical. This issue affects the function md_cloned_bio of the component raid1/raid10. The manipulation with an unknown input leads to a out-of-bounds write vulnerability. Using CWE to declare the problem leads to CWE-787. The product writes data past the end, or before the beginning, of the intended buffer. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: md/raid1,raid10: fix bio accounting for split md cloned bios Use md_cloned_bio() to control bio accounting instead of relying on r1bio_existed in raid1 or the io_accounting flag in raid10. The previous logic does not reliably reflect whether a bio is an md cloned bio. When a failed bio is split and resubmitted via bio_submit_split_bioset() on the error path, this can lead to either double accounting for md cloned bios, or missing accounting for bios returned from bio_submit_split_bioset() Fix this by using md_cloned_bio() to detect md cloned bios and skip accounting accordingly.

The advisory is shared at git.kernel.org. The identification of this vulnerability is CVE-2026-74373 since 08/15/2026. The exploitation is known to be easy. An attack has to be approached locally. Additional levels of successful authentication are needed for exploitation. Technical details are known, but no exploit is available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 08/15/2026).

Applying the patch bb8d7ea74206b419aa05d7773a15a923b668c9f0/ba976e3501111d11c550848b3b7341a73035f582 is able to eliminate this problem.

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

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

License

• open-source

Website

• Vendor: https://www.kernel.org/

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

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