Bug 2516772 (CVE-2026-74373)

Summary: CVE-2026-74373 kernel: md/raid1,raid10: fix bio accounting for split md cloned bios
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
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Priority: low    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel's md/raid1 and raid10 components. This flaw involves incorrect accounting of block I/O (bio) operations for split cloned bios. When a failed bio is split and resubmitted, the system may either double count or miss accounting for these bios. This can lead to resource management issues and potential system instability.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-08-15 06:32:41 UTC 
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.
Comment 1 gkamathe 2026-08-19 08:10:15 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026081503-CVE-2026-74373-9244@gregkh/T