CVE-2026-98580

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: nfc: llcp: Fix race condition in accept_queue lifecycle In nfc_llcp_socket_release(), sockets and listener accept queues are walked under the local sockets rwlock and bh_lock_sock(). However, bh_lock_sock() does not synchronise against process-context lock_sock() held by nfc_llcp_accept_dequeue() during accept(). Because socket_release() does not check sock_owned_by_user(), both paths can concurrently unlink and release the same child socket, resulting in use-after-free or a NULL pointer dereference of child->parent in nfc_llcp_accept_unlink(). Fix this synchronisation race by having nfc_llcp_socket_release() use process-context lock_sock() instead of bh_lock_sock(): 1. Pop sockets from the local sockets list under the write lock using nfc_llcp_sock_list_pop() so lock_sock() can be acquired without holding the rwlock. 2. Because lock_sock() can sleep, defer the final release of the nfc_llcp_local structure to a workqueue (release_work). This avoids a sleeping-in-atomic bug when the last local reference is dropped from softirq context. Additionally, hold a single device reference on local from registration until final destruction. 3. In nfc_llcp_local_get(), use kref_get_unless_zero() to prevent resurrecting a local object whose teardown has been scheduled. 4. In llcp_sock_accept(), verify that the listener socket state is still LLCP_LISTEN after waking from schedule_timeout() to prevent hangs if the listener is closed concurrently. 5. When unlinking unaccepted child sockets during listener release, unlink them from local->sockets, call sock_orphan(), and drop their initial sk_alloc creation reference via sock_put(). 6. Make nfc_llcp_accept_unlink() idempotent by guarding parent access with a NULL check.

Severity

Not scored

CVSS score

Not available

Vulnerability status

Received

Source identifier

416baaa9-dc9f-4396-8d5f-8c081fb06d67

Published

2026-10-18 16:17:10.483000

Last modified

2026-10-19 10:19:18.640000

View original CVE JSON

{
  "id": "CVE-2026-98580",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-10-18T16:17:10.483",
  "lastModified": "2026-10-19T10:19:18.640",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnfc: llcp: Fix race condition in accept_queue lifecycle\n\nIn nfc_llcp_socket_release(), sockets and listener accept queues are\nwalked under the local sockets rwlock and bh_lock_sock().  However,\nbh_lock_sock() does not synchronise against process-context lock_sock()\nheld by nfc_llcp_accept_dequeue() during accept().  Because\nsocket_release() does not check sock_owned_by_user(), both paths can\nconcurrently unlink and release the same child socket, resulting in\nuse-after-free or a NULL pointer dereference of child->parent in\nnfc_llcp_accept_unlink().\n\nFix this synchronisation race by having nfc_llcp_socket_release() use\nprocess-context lock_sock() instead of bh_lock_sock():\n\n1. Pop sockets from the local sockets list under the write lock using\n   nfc_llcp_sock_list_pop() so lock_sock() can be acquired without\n   holding the rwlock.\n\n2. Because lock_sock() can sleep, defer the final release of the\n   nfc_llcp_local structure to a workqueue (release_work).  This avoids\n   a sleeping-in-atomic bug when the last local reference is dropped\n   from softirq context.  Additionally, hold a single device reference\n   on local from registration until final destruction.\n\n3. In nfc_llcp_local_get(), use kref_get_unless_zero() to prevent\n   resurrecting a local object whose teardown has been scheduled.\n\n4. In llcp_sock_accept(), verify that the listener socket state is still\n   LLCP_LISTEN after waking from schedule_timeout() to prevent hangs if\n   the listener is closed concurrently.\n\n5. When unlinking unaccepted child sockets during listener release,\n   unlink them from local->sockets, call sock_orphan(), and drop their\n   initial sk_alloc creation reference via sock_put().\n\n6. Make nfc_llcp_accept_unlink() idempotent by guarding parent access with\n   a NULL check."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "net/nfc/llcp.h",
            "net/nfc/llcp_core.c",
            "net/nfc/llcp_sock.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "50b78b2a6500d0e97c204c1b6c51df8c17358bbe",
              "lessThan": "54adcabb0f1deef1bdae5fc64779ed6d442721c9",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "50b78b2a6500d0e97c204c1b6c51df8c17358bbe",
              "lessThan": "7c938aad5108382c6ad7453c4b5ee8ae3f3252ed",
              "versionType": "git",
              "status": "affected"
            },
            {
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              "lessThan": "d2093a0981138876212bc5f473bdbfba0786e064",
              "versionType": "git",
              "status": "affected"
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            {
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              "lessThan": "41256821762a7114906b178826d17098e2fa5992",
              "versionType": "git",
              "status": "affected"
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            {
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              "lessThan": "53867f6acb1af7f12d6485fa8a2819318f89083b",
              "versionType": "git",
              "status": "affected"
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            {
              "version": "50b78b2a6500d0e97c204c1b6c51df8c17358bbe",
              "lessThan": "da8a07757383614a8380a0f7dd54749d2687b82e",
              "versionType": "git",
              "status": "affected"
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            {
              "version": "50b78b2a6500d0e97c204c1b6c51df8c17358bbe",
              "lessThan": "d5e1c92d09caed19f2988739695ce611a86ba6f8",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "50b78b2a6500d0e97c204c1b6c51df8c17358bbe",
              "lessThan": "c3eef2f988a3db9690369d7cef9a3344dd9788d3",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "net/nfc/llcp.h",
            "net/nfc/llcp_core.c",
            "net/nfc/llcp_sock.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "3.7",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "3.7",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "5.10.271",
              "lessThanOrEqual": "5.10.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "5.15.222",
              "lessThanOrEqual": "5.15.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.1.189",
              "lessThanOrEqual": "6.1.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.6.158",
              "lessThanOrEqual": "6.6.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.12.112",
              "lessThanOrEqual": "6.12.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.55",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2.9",
              "lessThanOrEqual": "7.2.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.3",
              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {},
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/41256821762a7114906b178826d17098e2fa5992",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
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      "url": "https://git.kernel.org/stable/c/c3eef2f988a3db9690369d7cef9a3344dd9788d3",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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}