CVE-2026-74373 md/raid1,raid10: fix bio accounting for split md cloned bios
A bug in Linux kernel RAID1/10 bio accounting causes incorrect statistics, potentially leading to resource management issues or denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-74373?
CVE-2026-74373 is a vulnerability in Linux, published on 15 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
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.
Which versions are affected by CVE-2026-74373?
How do I fix CVE-2026-74373?
Apply the vendor's patch.
Is CVE-2026-74373 being exploited?
There is no known exploitation of CVE-2026-74373 in the wild and no public exploit code.
Sources
Also known as AZL-96323, BELL-CVE-2026-74373, DEBIAN-CVE-2026-74373, GHSA-w5h2-43j2-4p8f, UBUNTU-CVE-2026-74373.