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        "text": "This content is licensed under the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/). If you distribute this content, or a modified version of it, you must provide attribution to Cloud Linux Inc. and provide a link to the original.",
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        "full_product_name": {
          "name": "linux-headers-4.19.0-28-amd64-0:4.19.325-1+tuxcare.els1.amd64 as a component of Debian 10",
          "product_id": "Debian-10:linux-headers-4.19.0-28-amd64-0:4.19.325-1+tuxcare.els1.amd64"
        },
        "product_reference": "linux-headers-4.19.0-28-amd64-0:4.19.325-1+tuxcare.els1.amd64",
        "relates_to_product_reference": "Debian-10"
      },
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "hyperv-daemons-0:4.19.325-1+tuxcare.els1.amd64 as a component of Debian 10",
          "product_id": "Debian-10:hyperv-daemons-0:4.19.325-1+tuxcare.els1.amd64"
        },
        "product_reference": "hyperv-daemons-0:4.19.325-1+tuxcare.els1.amd64",
        "relates_to_product_reference": "Debian-10"
      },
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "linux-image-4.19.0-28-amd64-unsigned-0:4.19.325-1+tuxcare.els1.amd64 as a component of Debian 10",
          "product_id": "Debian-10:linux-image-4.19.0-28-amd64-unsigned-0:4.19.325-1+tuxcare.els1.amd64"
        },
        "product_reference": "linux-image-4.19.0-28-amd64-unsigned-0:4.19.325-1+tuxcare.els1.amd64",
        "relates_to_product_reference": "Debian-10"
      }
    ]
  },
  "vulnerabilities": [
    {
      "cve": "CVE-2026-64109",
      "cwe": {
        "id": "CWE-416",
        "name": "Use After Free"
      },
      "notes": [
        {
          "category": "description",
          "text": "In the Linux kernel, the following vulnerability has been resolved:\n\naf_unix: Fix UAF read of tail->len in unix_stream_data_wait()\n\nunix_stream_data_wait() does skb_peek_tail(&sk->sk_receive_queue) without\nholding any lock that prevents SKBs on that queue from being dequeued and\nfreed.\nThis has been the case since commit 79f632c71bea (\"unix/stream: fix\npeeking with an offset larger than data in queue\").\nThe first consequence of this is that the pointer comparison\n`tail != last` can be false even if `last` semantically refers to an\nalready-freed SKB while `tail` is a new SKB allocated at the same address;\nwhich can cause unix_stream_data_wait() to wrongly keep blocking after new\ndata has arrived, but only in a weird scenario where a peeking recv() and\na normal recv() on the same socket are racing, which is probably not a\nreal problem.\n\nBut since commit 2b514574f7e8 (\"net: af_unix: implement splice for stream\naf_unix sockets\"), `tail` is actually dereferenced, which can cause UAF in\nthe following race scenario (where test_setup() runs single-threaded,\nand afterwards, test_thread1() and test_thread2() run concurrently in\ntwo threads:\n```\nstatic int socks[2];\nvoid test_setup(void) {\n  socketpair(AF_UNIX, SOCK_STREAM, 0, socks);\n  send(socks[1], \"A\", 1, 0);\n  int peekoff = 1;\n  setsockopt(socks[0], SOL_SOCKET, SO_PEEK_OFF, &peekoff, sizeof(peekoff));\n}\nvoid test_thread1(void) {\n  char dummy;\n  recv(socks[0], &dummy, 1, MSG_PEEK);\n}\nvoid test_thread2(void) {\n  char dummy;\n  recv(socks[0], &dummy, 1, 0);\n  shutdown(socks[1], SHUT_WR);\n}\n```\n\nwhen racing like this:\n```\nthread1                       thread2\nunix_stream_read_generic\n  mutex_lock(&u->iolock)\n  skb_peek(&sk->sk_receive_queue)\n  skb_peek_next(skb, &sk->sk_receive_queue)\n  mutex_unlock(&u->iolock)\n                              unix_stream_read_generic\n                                unix_state_lock(sk)\n                                skb_peek(&sk->sk_receive_queue)\n                                unix_state_unlock(sk)\n  unix_stream_data_wait\n    unix_state_lock(sk)\n    tail = skb_peek_tail(&sk->sk_receive_queue)\n                                spin_lock(&sk->sk_receive_queue.lock)\n                                __skb_unlink(skb, &sk->sk_receive_queue)\n                                spin_unlock(&sk->sk_receive_queue.lock)\n                                consume_skb(skb) [frees the SKB]\n    `tail != last`: false\n    `tail`: true\n    `tail->len != last_len` ***UAF***\n```\n\nFix the UAF by removing the read of tail->len; checking tail->len would\nonly make sense if SKBs in the receive queue of a UNIX socket could grow,\nwhich can no longer happen.\n\nKuniyuki explained:\n\n> When commit 869e7c62486e (\"net: af_unix: implement stream sendpage\n> support\") added sendpage() support, data could be appended to the last\n> skb in the receiver's queue.\n>\n> That's why we needed to check if the length of the last skb was changed\n> while waiting for new data in unix_stream_data_wait().\n>\n> However, commit a0dbf5f818f9 (\"af_unix: Support MSG_SPLICE_PAGES\") and\n> commit 57d44a354a43 (\"unix: Convert unix_stream_sendpage() to use\n> MSG_SPLICE_PAGES\") refactored sendmsg(), and now data is always added\n> to a new skb.\n\nThat means this fix is not suitable for kernels before 6.5.",
          "title": "Vulnerability description"
        }
      ],
      "product_status": {
        "under_investigation": [
          "Debian-10:hyperv-daemons-0:4.19.325-1+tuxcare.els1.amd64",
          "Debian-10:libbpf-dev-0:4.19.325-1+tuxcare.els1.amd64",
          "Debian-10:libbpf4.19-0:4.19.325-1+tuxcare.els1.amd64",
          "Debian-10:libcpupower-dev-0:4.19.325-1+tuxcare.els1.amd64",
          "Debian-10:libcpupower1-0:4.19.325-1+tuxcare.els1.amd64",
          "Debian-10:linux-compiler-gcc-8-x86-0:4.19.325-1+tuxcare.els1.amd64",
          "Debian-10:linux-config-4.19-0:4.19.325-1+tuxcare.els1.amd64",
          "Debian-10:linux-cpupower-0:4.19.325-1+tuxcare.els1.amd64",
          "Debian-10:linux-doc-4.19-0:4.19.325-1+tuxcare.els1.all",
          "Debian-10:linux-headers-4.19.0-28-all-0:4.19.325-1+tuxcare.els1.amd64",
          "Debian-10:linux-headers-4.19.0-28-all-amd64-0:4.19.325-1+tuxcare.els1.amd64",
          "Debian-10:linux-headers-4.19.0-28-amd64-0:4.19.325-1+tuxcare.els1.amd64",
          "Debian-10:linux-headers-4.19.0-28-common-0:4.19.325-1+tuxcare.els1.all",
          "Debian-10:linux-image-4.19.0-28-amd64-unsigned-0:4.19.325-1+tuxcare.els1.amd64",
          "Debian-10:linux-image-amd64-signed-template-0:4.19.325-1+tuxcare.els1.amd64",
          "Debian-10:linux-kbuild-4.19-0:4.19.325-1+tuxcare.els1.amd64",
          "Debian-10:linux-libc-dev-0:4.19.325-1+tuxcare.els1.amd64",
          "Debian-10:linux-perf-4.19-0:4.19.325-1+tuxcare.els1.amd64",
          "Debian-10:linux-source-4.19-0:4.19.325-1+tuxcare.els1.all",
          "Debian-10:linux-support-4.19.0-28-0:4.19.325-1+tuxcare.els1.all"
        ]
      },
      "references": [
        {
          "category": "self",
          "summary": "Canonical URL",
          "url": "https://cve.tuxcare.com/els/cve/CVE-2026-64109"
        },
        {
          "category": "external",
          "summary": "https://git.kernel.org/stable/c/26342087fac93b3932e6af61dc91ec029cb8a623",
          "url": "https://git.kernel.org/stable/c/26342087fac93b3932e6af61dc91ec029cb8a623"
        },
        {
          "category": "external",
          "summary": "https://git.kernel.org/stable/c/38bccb927d83d7d52e5b20015a172a0b6101d11e",
          "url": "https://git.kernel.org/stable/c/38bccb927d83d7d52e5b20015a172a0b6101d11e"
        },
        {
          "category": "external",
          "summary": "https://git.kernel.org/stable/c/5f162f95a95834f06a8ec6140889272ad12e842f",
          "url": "https://git.kernel.org/stable/c/5f162f95a95834f06a8ec6140889272ad12e842f"
        },
        {
          "category": "external",
          "summary": "https://git.kernel.org/stable/c/acdff9907478e82208475b1151700d0b71dcdc63",
          "url": "https://git.kernel.org/stable/c/acdff9907478e82208475b1151700d0b71dcdc63"
        },
        {
          "category": "external",
          "summary": "https://git.kernel.org/stable/c/be309f8eae8b474a4a617eaae01324da996fc719",
          "url": "https://git.kernel.org/stable/c/be309f8eae8b474a4a617eaae01324da996fc719"
        }
      ],
      "release_date": "2026-07-19T16:17:00Z",
      "remediations": [
        {
          "category": "none_available",
          "date": "2026-08-13T13:17:35.463974Z",
          "details": "Affected",
          "product_ids": [
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}