CVE-2026-89577 dm-io: report non-retryable errors separatedly
A flaw in the Linux kernel dm-io subsystem could cause unnecessary RAID leg failures, leading to denial of service for local users.
- 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-2026-89577?
CVE-2026-89577 is a denial of service vulnerability in Linux, published on 11 Sep 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:
dm-io: report non-retryable errors separatedly
The error codes BLK_STS_NOTSUPP and BLK_STS_INVAL should not cause leg failure on dm-raid1. This patch changes the interface to dm-io, so that it reports two error bitmaps - error_bits and unsup_bits. The unsup_bit bitmap tracks BLK_STS_NOTSUPP or BLK_STS_INVAL errors, the error_bits bitmap tracks all the other errors.
dm-raid1 is changed so that it won't fail a leg if it receives an error in the unsup_bits bitmap.
This patch (with 62dc37a819a5) fixes misbehavior if the user uses unaligned bio vectors on dm-raid1.
Which versions are affected by CVE-2026-89577?
How do I fix CVE-2026-89577?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-89577 being exploited?
There is no known exploitation of CVE-2026-89577 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-89577, DEBIAN-CVE-2026-89577, GHSA-fm7m-v5fw-6w27, UBUNTU-CVE-2026-89577.