FKIE_CVE-2026-74589

Vulnerability from fkie_nvd - Published: 2026-08-22 16:16 - Updated: 2026-10-14 13:10
Severity
8.4 (High) - CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: bpf, sockmap: Fix sk_redir use-after-free in send verdict sk_psock_msg_verdict() takes a socket reference for psock->sk_redir. tcp_bpf_send_verdict() copies that pointer while holding the source socket lock, but does not take a reference for the local copy before dropping the lock around tcp_bpf_sendmsg_redir(). When apply_bytes keeps the cached verdict active, another sendmsg() on the same source socket can consume the remaining bytes and release the cached reference while the first thread still holds only the raw local pointer: CPU 0 CPU 1 sk_redir = psock->sk_redir apply_bytes remains nonzero release_sock(sk) lock_sock(sk) apply_bytes reaches zero psock->sk_redir = NULL release_sock(sk) tcp_bpf_sendmsg_redir(sk_redir) sock_put(sk_redir) tcp_bpf_sendmsg_redir(sk_redir) The final sock_put() can free sk_redir before CPU 0 dereferences it. KASAN reported: BUG: KASAN: slab-use-after-free in tcp_bpf_sendmsg_redir+0xf39/0x1020 Read of size 8 at addr ffff888108537090 by task poc/87 Call Trace: tcp_bpf_sendmsg_redir+0xf39/0x1020 tcp_bpf_sendmsg+0x977/0x1a50 __sys_sendto+0x32c/0x3a0 __x64_sys_sendto+0xdb/0x1b0 Allocated by task 85: sk_prot_alloc+0x56/0x210 sk_clone+0x6f/0x14b0 inet_csk_clone_lock+0x24/0x740 tcp_create_openreq_child+0x25/0x2710 tcp_v4_syn_recv_sock+0x10a/0xe00 Freed by task 0: __kasan_slab_free+0x43/0x70 slab_free_after_rcu_debug+0xa6/0x1e0 rcu_core+0x50a/0x1850 Last potentially related work creation: __sk_destruct+0x3da/0x540 sk_psock_destroy+0x81e/0xab0 process_one_work+0x63a/0x1070 Take a temporary socket reference while the source socket lock still protects psock->sk_redir, and drop it after tcp_bpf_sendmsg_redir() returns. This keeps each unlocked use independent of cached-verdict ownership.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/1cec526cf0a2227395f2c2f4b671cb052ff0b00e
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/41b7da0cb72ca5aa1e62b68dab323d0791fc6bdf
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/4c9d9aa809c261dc0490a0e19d675f7e8e4c85bf
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/90a19b0894ba79a699b48cf44421b36fbd566e99
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/9b4fbc371a6ecf1b4e43b5a629015cc0830d8de3
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/a14e4ef1d90c3418f01b3b6b8fd3a40a0a208a10
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/a76624733730e541e4955fdecf506af2f6b20558
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/d192cff2a37d59206dabe6ec2e60ceac6271f274
Impacted products
Vendor Product Version
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{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/ipv4/tcp_bpf.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "41b7da0cb72ca5aa1e62b68dab323d0791fc6bdf",
              "status": "affected",
              "version": "604326b41a6fb9b4a78b6179335decee0365cd8c",
              "versionType": "git"
            },
            {
              "lessThan": "9b4fbc371a6ecf1b4e43b5a629015cc0830d8de3",
              "status": "affected",
              "version": "604326b41a6fb9b4a78b6179335decee0365cd8c",
              "versionType": "git"
            },
            {
              "lessThan": "90a19b0894ba79a699b48cf44421b36fbd566e99",
              "status": "affected",
              "version": "604326b41a6fb9b4a78b6179335decee0365cd8c",
              "versionType": "git"
            },
            {
              "lessThan": "d192cff2a37d59206dabe6ec2e60ceac6271f274",
              "status": "affected",
              "version": "604326b41a6fb9b4a78b6179335decee0365cd8c",
              "versionType": "git"
            },
            {
              "lessThan": "4c9d9aa809c261dc0490a0e19d675f7e8e4c85bf",
              "status": "affected",
              "version": "604326b41a6fb9b4a78b6179335decee0365cd8c",
              "versionType": "git"
            },
            {
              "lessThan": "a14e4ef1d90c3418f01b3b6b8fd3a40a0a208a10",
              "status": "affected",
              "version": "604326b41a6fb9b4a78b6179335decee0365cd8c",
              "versionType": "git"
            },
            {
              "lessThan": "1cec526cf0a2227395f2c2f4b671cb052ff0b00e",
              "status": "affected",
              "version": "604326b41a6fb9b4a78b6179335decee0365cd8c",
              "versionType": "git"
            },
            {
              "lessThan": "a76624733730e541e4955fdecf506af2f6b20558",
              "status": "affected",
              "version": "604326b41a6fb9b4a78b6179335decee0365cd8c",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/ipv4/tcp_bpf.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "4.20"
            },
            {
              "lessThan": "4.20",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.265",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.216",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.183",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.152",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.104",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.45",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.9",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf, sockmap: Fix sk_redir use-after-free in send verdict\n\nsk_psock_msg_verdict() takes a socket reference for psock-\u003esk_redir.\ntcp_bpf_send_verdict() copies that pointer while holding the source socket\nlock, but does not take a reference for the local copy before dropping the\nlock around tcp_bpf_sendmsg_redir().\n\nWhen apply_bytes keeps the cached verdict active, another sendmsg() on the\nsame source socket can consume the remaining bytes and release the cached\nreference while the first thread still holds only the raw local pointer:\n\n  CPU 0                                  CPU 1\n  sk_redir = psock-\u003esk_redir\n  apply_bytes remains nonzero\n  release_sock(sk)\n                                         lock_sock(sk)\n                                         apply_bytes reaches zero\n                                         psock-\u003esk_redir = NULL\n                                         release_sock(sk)\n                                         tcp_bpf_sendmsg_redir(sk_redir)\n                                         sock_put(sk_redir)\n  tcp_bpf_sendmsg_redir(sk_redir)\n\nThe final sock_put() can free sk_redir before CPU 0 dereferences it.\n\nKASAN reported:\n\n  BUG: KASAN: slab-use-after-free in tcp_bpf_sendmsg_redir+0xf39/0x1020\n  Read of size 8 at addr ffff888108537090 by task poc/87\n  Call Trace:\n   tcp_bpf_sendmsg_redir+0xf39/0x1020\n   tcp_bpf_sendmsg+0x977/0x1a50\n   __sys_sendto+0x32c/0x3a0\n   __x64_sys_sendto+0xdb/0x1b0\n  Allocated by task 85:\n   sk_prot_alloc+0x56/0x210\n   sk_clone+0x6f/0x14b0\n   inet_csk_clone_lock+0x24/0x740\n   tcp_create_openreq_child+0x25/0x2710\n   tcp_v4_syn_recv_sock+0x10a/0xe00\n  Freed by task 0:\n   __kasan_slab_free+0x43/0x70\n   slab_free_after_rcu_debug+0xa6/0x1e0\n   rcu_core+0x50a/0x1850\n  Last potentially related work creation:\n   __sk_destruct+0x3da/0x540\n   sk_psock_destroy+0x81e/0xab0\n   process_one_work+0x63a/0x1070\n\nTake a temporary socket reference while the source socket lock still\nprotects psock-\u003esk_redir, and drop it after tcp_bpf_sendmsg_redir()\nreturns.  This keeps each unlocked use independent of cached-verdict\nownership."
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nbpf, sockmap: Correcci\u00f3n de uso despu\u00e9s de liberaci\u00f3n de sk_redir en el veredicto de env\u00edo\n\nsk_psock_msg_verdict() toma una referencia de socket para psock -\u003e sk_redir.\ntcp_bpf_send_verdict() copia ese puntero mientras mantiene el bloqueo del socket de origen, pero no toma una referencia para la copia local antes de liberar el bloqueo alrededor de tcp_bpf_sendmsg_redir().\n\nCuando apply_bytes mantiene activo el veredicto en cach\u00e9, otro sendmsg() en el mismo socket de origen puede consumir los bytes restantes y liberar la referencia en cach\u00e9 mientras el primer hilo a\u00fan mantiene solo el puntero local sin procesar:\n\n  CPU 0                                  CPU 1\n  sk_redir = psock -\u003e sk_redir\n  apply_bytes permanece distinto de cero\n  release_sock(sk)\n                                         lock_sock(sk)\n                                         apply_bytes llega a cero\n                                         psock -\u003e sk_redir = NULL\n                                         release_sock(sk)\n                                         tcp_bpf_sendmsg_redir(sk_redir)\n                                         sock_put(sk_redir)\n  tcp_bpf_sendmsg_redir(sk_redir)\n\nEl sock_put() final puede liberar sk_redir antes de que la CPU 0 lo desreferencie.\n\nKASAN inform\u00f3:\n\n  BUG: KASAN: uso despu\u00e9s de liberaci\u00f3n de slab en tcp_bpf_sendmsg_redir+0xf39/0x1020\n  Lectura de tama\u00f1o 8 en la direcci\u00f3n ffff888108537090 por la tarea PoC/87\n  Traza de Llamada:\n   tcp_bpf_sendmsg_redir+0xf39/0x1020\n   tcp_bpf_sendmsg+0x977/0x1a50\n   __sys_sendto+0x32c/0x3a0\n   __x64_sys_sendto+0xdb/0x1b0\n  Asignado por la tarea 85:\n   sk_prot_alloc+0x56/0x210\n   sk_clone+0x6f/0x14b0\n   inet_csk_clone_lock+0x24/0x740\n   tcp_create_openreq_child+0x25/0x2710\n   tcp_v4_syn_recv_sock+0x10a/0xe00\n  Liberado por la tarea 0:\n   __kasan_slab_free+0x43/0x70\n   slab_free_after_rcu_debug+0xa6/0x1e0\n   rcu_core+0x50a/0x1850\n  \u00daltima creaci\u00f3n de trabajo potencialmente relacionada:\n   __sk_destruct+0x3da/0x540\n   sk_psock_destroy+0x81e/0xab0\n   process_one_work+0x63a/0x1070\n\nToma una referencia de socket temporal mientras el bloqueo del socket de origen a\u00fan protege psock -\u003e sk_redir, y lib\u00e9rala despu\u00e9s de que tcp_bpf_sendmsg_redir() retorne. Esto mantiene cada uso desbloqueado independiente de la propiedad del veredicto en cach\u00e9."
    }
  ],
  "id": "CVE-2026-74589",
  "lastModified": "2026-10-14T13:10:00.187",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 8.4,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 2.5,
        "impactScore": 5.9,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-08-22T16:16:31.097",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/1cec526cf0a2227395f2c2f4b671cb052ff0b00e"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/41b7da0cb72ca5aa1e62b68dab323d0791fc6bdf"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/4c9d9aa809c261dc0490a0e19d675f7e8e4c85bf"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/90a19b0894ba79a699b48cf44421b36fbd566e99"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/9b4fbc371a6ecf1b4e43b5a629015cc0830d8de3"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/a14e4ef1d90c3418f01b3b6b8fd3a40a0a208a10"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/a76624733730e541e4955fdecf506af2f6b20558"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/d192cff2a37d59206dabe6ec2e60ceac6271f274"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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