CVE-2026-53281 iommu/vt-d: Avoid NULL pointer dereference or refcount corruption
A NULL pointer dereference in the Linux kernel IOMMU driver can cause a crash or potential use-after-free during device teardown.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-53281?
CVE-2026-53281 is a high-severity vulnerability in Linux kernel, published on 26 Jun 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:
iommu/vt-d: Avoid NULL pointer dereference or refcount corruption
Commit 60f030f7418d ("iommu/vt-d: Avoid use of NULL after WARN_ON_ONCE") fixed a NULL pointer dereference in an unlikely situation partly.
If dev_pasid is not found in the dev_pasids list, it remains NULL. However, the teardown operations are executed unconditionally, this lead to a NULL pointer dereference or refcount corruption.
If the domain was never attached to this IOMMU, info will be NULL, which would cause an immediate dereference when checking --info->refcnt.
Even if info is not NULL, decrementing the refcount without having removed a valid PASID might unbalance the count. This could lead to premature dropping of the refcount to 0, potentially causing a use-after-free for the remaining active devices sharing the domain.
Fix it by returning early if dev_pasid is NULL, before executing the teardown operations.
Issue found by AI review and suggested by Kevin Tian. https://sashiko.dev/#/patchset/20260421031347.1408890-1-zhenzhong.duan%40intel.com
Weakness: CWE-476
Which versions are affected by CVE-2026-53281?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-53281?
Apply the vendor's patch.
Is CVE-2026-53281 being exploited?
There is no known exploitation of CVE-2026-53281 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2026-53281, DEBIAN-CVE-2026-53281, GHSA-p9cf-q2gf-35mq, ROOT-OS-DEBIAN-13-CVE-2026-53281, ROOT-OS-UBUNTU-2404-CVE-2026-53281, UBUNTU-CVE-2026-53281.