# CVE-2026-90387: swiotlb: Preserve allocation virtual address for dynamic pools

> Incorrect virtual address handling in Linux kernel swiotlb dynamic pools can cause memory free failures, potentially leading to system crashes.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **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:** Yes
- **Published:** 17 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-102470, BELL-CVE-2026-90387, DEBIAN-CVE-2026-90387, GHSA-rw87-3jgx-gg57, UBUNTU-CVE-2026-90387

## What is CVE-2026-90387?

CVE-2026-90387 is a high-severity vulnerability in Linux, published on 17 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:

swiotlb: Preserve allocation virtual address for dynamic pools

swiotlb_alloc_tlb() can allocate from the DMA atomic pool when a decrypted
pool is needed from atomic context. With CONFIG_DMA_DIRECT_REMAP, the
atomic pool is backed by remapped virtual addresses, which are not the same
as the direct-map addresses returned by phys_to_virt().

swiotlb_init_io_tlb_pool() currently reconstructs the pool virtual address
from the physical start address. For atomic-pool backed allocations this
stores the wrong address in pool->vaddr. Later, swiotlb_free_tlb() passes
that address to dma_free_from_pool(), which will fail to recognize the
chunk

Pass the virtual address returned by the allocation path into
swiotlb_init_io_tlb_pool(), and store that address in pool->vaddr. This
keeps the pool free path using the same virtual address as the allocator.

## Which versions are affected by CVE-2026-90387?


## How do I fix CVE-2026-90387?

Apply the vendor's patch.

## Is CVE-2026-90387 being exploited?

There is no known exploitation of CVE-2026-90387 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-90387 and fix it if it is affected.

What it is: CVE-2026-90387 is a high-severity vulnerability in Linux, published on 17 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-90387 in the wild and no public exploit code.

Affected product: Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-90387/ (Markdown: https://insights.sbomify.com/CVE-2026-90387/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-90387
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-90387
- OSV: https://osv.dev/vulnerability/CVE-2026-90387

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-90387/
Summaries are generated and may contain mistakes; the official description above is the record.