CVE-2026-98342: Linux Vulnerability

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.

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

Vendor	Product	Versions
Linux	Linux	>= 2ba05622b8b143b0c95968ba59bddfbd6d2f2559, < ac8ce9f89638d6d79875cca7d8ae42566a9bde15; >= 2ba05622b8b143b0c95968ba59bddfbd6d2f2559, < 14578c78405d51fa92e4ada4502a45f537c0fcb8; >= 2ba05622b8b143b0c95968ba59bddfbd6d2f2559, < cbb3310a5167e868a5e763e32b9a23b4d50669ee; >= 2ba05622b8b143b0c95968ba59bddfbd6d2f2559, < 8577a5ec4f7e00443015ef99f646def093121a1b; >= 2ba05622b8b143b0c95968ba59bddfbd6d2f2559, < 4448a539a0c39141cccc67be6cacde0f35024313; >= 2ba05622b8b143b0c95968ba59bddfbd6d2f2559, < fc1f4884f1d46fc7a8cee6e2997ecc9e8d1c7f77; >= 2ba05622b8b143b0c95968ba59bddfbd6d2f2559, < 4aed7e47a10b94ea3c5171e8d1382081accd2e03; >= 2ba05622b8b143b0c95968ba59bddfbd6d2f2559, < dc750422170a563c7a81f6e49d36bb02c62ae37f
Linux	Linux	2.6.29

References

Timeline

Published: Oct 6, 2026
Last Modified: Oct 6, 2026
Status: Received

Frequently Asked Questions

What is CVE-2026-98342?

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.

How severe is CVE-2026-98342?

Severity scoring for CVE-2026-98342 is pending analysis.

How do I fix CVE-2026-98342?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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