FKIE_CVE-2026-74666

Vulnerability from fkie_nvd - Published: 2026-08-22 16:16 - Updated: 2026-08-27 13:18
Severity
7.8 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: packet: synchronize pressure clearing with ring reconfiguration packet_set_ring() updates the RX ring state under sk_receive_queue.lock, but used to publish the tpacket receive mode through po->prot_hook.func after releasing that lock. packet_poll() and packet_recvmsg() can then run the pressure clearing path after the ring has been cleared while still seeing tpacket_rcv, causing __packet_rcv_has_room() to dereference stale or NULL ring storage. Move the existing receive hook assignment into the same sk_receive_queue.lock section as the ring state update. Keep the assignment otherwise unchanged, including on TX ring reconfiguration, to avoid adding behavior changes that are not required for the fix. Serialize packet_recvmsg() pressure clearing with the same queue lock only after PACKET_SOCK_PRESSURE has been observed. If the flag is clear and the socket has moved away from tpacket_rcv, packet_set_ring() has already detached the socket and waited for synchronize_net(), so no new packet input can set the flag again. packet_poll() already holds sk_receive_queue.lock, so it uses the new unlocked helper directly.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/1a35da325cac4d5bcad76a2aa943408a6f1d9000
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/2c7b5eb87b2b288cdbde825f21d2b83b2f5da747
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/8cfb2e71926a682f36c4240067d424074dd8f70f
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/a08196c3cc105947746ec21309edfbb60275fcdb
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/ad740b4990347521f0db260d381f9f74e7b340ba
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/bf3c8e86bc8ad111be3f3136125e255344bcb3da
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/cf8189b82bb93f219ab740e0346c919ad65ada62
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/f015c9de92b731814059a343b765c60c0196225c
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/packet/af_packet.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "bf3c8e86bc8ad111be3f3136125e255344bcb3da",
              "status": "affected",
              "version": "2ccdbaa6d55b0656244ba57c4b56765a0af76c0a",
              "versionType": "git"
            },
            {
              "lessThan": "8cfb2e71926a682f36c4240067d424074dd8f70f",
              "status": "affected",
              "version": "2ccdbaa6d55b0656244ba57c4b56765a0af76c0a",
              "versionType": "git"
            },
            {
              "lessThan": "f015c9de92b731814059a343b765c60c0196225c",
              "status": "affected",
              "version": "2ccdbaa6d55b0656244ba57c4b56765a0af76c0a",
              "versionType": "git"
            },
            {
              "lessThan": "cf8189b82bb93f219ab740e0346c919ad65ada62",
              "status": "affected",
              "version": "2ccdbaa6d55b0656244ba57c4b56765a0af76c0a",
              "versionType": "git"
            },
            {
              "lessThan": "ad740b4990347521f0db260d381f9f74e7b340ba",
              "status": "affected",
              "version": "2ccdbaa6d55b0656244ba57c4b56765a0af76c0a",
              "versionType": "git"
            },
            {
              "lessThan": "2c7b5eb87b2b288cdbde825f21d2b83b2f5da747",
              "status": "affected",
              "version": "2ccdbaa6d55b0656244ba57c4b56765a0af76c0a",
              "versionType": "git"
            },
            {
              "lessThan": "a08196c3cc105947746ec21309edfbb60275fcdb",
              "status": "affected",
              "version": "2ccdbaa6d55b0656244ba57c4b56765a0af76c0a",
              "versionType": "git"
            },
            {
              "lessThan": "1a35da325cac4d5bcad76a2aa943408a6f1d9000",
              "status": "affected",
              "version": "2ccdbaa6d55b0656244ba57c4b56765a0af76c0a",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/packet/af_packet.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "4.2"
            },
            {
              "lessThan": "4.2",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.267",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.218",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.185",
              "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\npacket: synchronize pressure clearing with ring reconfiguration\n\npacket_set_ring() updates the RX ring state under sk_receive_queue.lock,\nbut used to publish the tpacket receive mode through po-\u003eprot_hook.func\nafter releasing that lock. packet_poll() and packet_recvmsg() can then\nrun the pressure clearing path after the ring has been cleared while\nstill seeing tpacket_rcv, causing __packet_rcv_has_room() to dereference\nstale or NULL ring storage.\n\nMove the existing receive hook assignment into the same\nsk_receive_queue.lock section as the ring state update. Keep the\nassignment otherwise unchanged, including on TX ring reconfiguration, to\navoid adding behavior changes that are not required for the fix.\n\nSerialize packet_recvmsg() pressure clearing with the same queue lock\nonly after PACKET_SOCK_PRESSURE has been observed. If the flag is clear\nand the socket has moved away from tpacket_rcv, packet_set_ring() has\nalready detached the socket and waited for synchronize_net(), so no new\npacket input can set the flag again.\n\npacket_poll() already holds sk_receive_queue.lock, so it uses the new\nunlocked helper directly."
    }
  ],
  "id": "CVE-2026-74666",
  "lastModified": "2026-08-27T13:18:36.643",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 7.8,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.9,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-08-22T16:16:40.467",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/1a35da325cac4d5bcad76a2aa943408a6f1d9000"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/2c7b5eb87b2b288cdbde825f21d2b83b2f5da747"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/8cfb2e71926a682f36c4240067d424074dd8f70f"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/a08196c3cc105947746ec21309edfbb60275fcdb"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/ad740b4990347521f0db260d381f9f74e7b340ba"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/bf3c8e86bc8ad111be3f3136125e255344bcb3da"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/cf8189b82bb93f219ab740e0346c919ad65ada62"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/f015c9de92b731814059a343b765c60c0196225c"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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