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dmaengine: wait for RCU readers before releasing dma_device

Type: advisorySources: OSV

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.

Products
Kernel
Affected versions
Not specified
Fixed versions
5.10.271, 5.15.222, 6.1.189, 6.12.112, 6.18.54, 6.6.158, 7.2.8
CVEs
CVE-2026-98342
Confirmed fixed CVEs
Not specified
Updated in this feed
5 Nov 2026, 00:54 UTC · Revision 1

Source evidence

dmaengine: wait for RCU readers before releasing dma_device

core-osv · Original source

Published 6 Oct 2026, 08:46 UTC

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.

osv:CVE-2026-98342

Kernel

Fixed versions: 5.10.271, 5.15.222, 6.1.189, 6.6.158, 6.12.112, 6.18.54, 7.2.8

Complete source record
{
  "id": "2de8d789930f2ca4338e13ad2367ab5ad7f4e25ab0f3ac0d750bc5eb866487ea",
  "url": "https://osv.dev/vulnerability/CVE-2026-98342",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "dmaengine: wait for RCU readers before releasing dma_device",
    "summary": "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.",
    "evidence": "osv:CVE-2026-98342",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "5.10.271",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "5.15.222",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.1.189",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.6.158",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.12.112",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.18.54",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "7.2.8",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2026-98342",
      "aliases": [
        "CVE-2026-98342"
      ],
      "affected": [
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              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
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                {
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                {
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                {
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          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98342.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "2.6.29"
                },
                {
                  "fixed": "5.10.271"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "5.11.0"
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                {
                  "fixed": "5.15.222"
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              ]
            },
            {
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                {
                  "introduced": "5.16.0"
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            },
            {
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            {
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                  "introduced": "6.7.0"
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            },
            {
              "type": "ECOSYSTEM",
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                  "introduced": "6.13.0"
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                {
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            },
            {
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          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98342.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:40.933149764Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/14578c78405d51fa92e4ada4502a45f537c0fcb8",
        "https://git.kernel.org/stable/c/4448a539a0c39141cccc67be6cacde0f35024313",
        "https://git.kernel.org/stable/c/4aed7e47a10b94ea3c5171e8d1382081accd2e03",
        "https://git.kernel.org/stable/c/8577a5ec4f7e00443015ef99f646def093121a1b",
        "https://git.kernel.org/stable/c/ac8ce9f89638d6d79875cca7d8ae42566a9bde15",
        "https://git.kernel.org/stable/c/cbb3310a5167e868a5e763e32b9a23b4d50669ee",
        "https://git.kernel.org/stable/c/dc750422170a563c7a81f6e49d36bb02c62ae37f",
        "https://git.kernel.org/stable/c/fc1f4884f1d46fc7a8cee6e2997ecc9e8d1c7f77",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98342.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-98342",
        "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
      ],
      "provider_metadata": {
        "cna_assigner": "Linux",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98342.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-98342",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 508724,
  "published_at": "2026-10-06T08:46:32.366+00:00"
}