CVE-2026-72438 md/raid10: fix writes_pending and barrier reference leaks on discard failures
A flaw in the Linux kernel's RAID10 driver causes resource leaks on discard failures, potentially leading to denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-72438?
CVE-2026-72438 is a high-severity denial of service vulnerability in Linux, published on 15 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
md/raid10: fix writes_pending and barrier reference leaks on discard failures
raid10_make_request() acquires a writes_pending reference with md_write_start() before calling raid10_handle_discard(). Several failure paths in raid10_handle_discard() complete the bio and return without releasing the corresponding reference, causing md_write_end() to be skipped.
Call md_write_end() before returning from these failure paths to keep writes_pending accounting balanced.
Additionally, discard split allocation failures can occur after wait_barrier() succeeds. Those paths return without calling allow_barrier(), leaking the associated barrier reference.
Release the barrier before returning from those paths.
Which versions are affected by CVE-2026-72438?
How do I fix CVE-2026-72438?
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-2026-72438 being exploited?
There is no known exploitation of CVE-2026-72438 in the wild and no public exploit code.
Sources
Also known as AZL-96063, BELL-CVE-2026-72438, DEBIAN-CVE-2026-72438, GHSA-cxhw-2fw5-695j, UBUNTU-CVE-2026-72438.