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FKIE_CVE-2026-64190

Vulnerability from fkie_nvd - Published: 2026-07-20 17:18 - Updated: 2026-08-11 19:06
Summary
In the Linux kernel, the following vulnerability has been resolved: net: team: fix NULL pointer dereference in team_xmit during mode change __team_change_mode() clears team->ops with memset() before restoring safe dummy handlers via team_adjust_ops(). A concurrent team_xmit() running under RCU on another CPU can read team->ops.transmit during this window and call a NULL function pointer, crashing the kernel. The race requires a mode change (CAP_NET_ADMIN) concurrent with transmit on the team device. BUG: kernel NULL pointer dereference, address: 0000000000000000 Oops: 0010 [#1] SMP KASAN NOPTI RIP: 0010:0x0 Call Trace: team_xmit (drivers/net/team/team_core.c:1853) dev_hard_start_xmit (net/core/dev.c:3904) __dev_queue_xmit (net/core/dev.c:4871) packet_sendmsg (net/packet/af_packet.c:3109) __sys_sendto (net/socket.c:2265) The original code assumed that no ports means no traffic, so mode changes could freely memset()/memcpy() the ops. AF_PACKET with forced carrier breaks that assumption. Prevent the race instead of making it safe: replace memset()/memcpy() with per-field updates that never touch transmit or receive. Those two handlers are managed solely by team_adjust_ops(), which already installs dummies when tx_en_port_count == 0 (always true during mode change since no ports are present). WRITE_ONCE/READ_ONCE prevent store/load tearing on the handler pointers. synchronize_net() before exit_op() drains in-flight readers that may still reference old mode state from before port removal switched the handlers to dummies.
Impacted products

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/net/team/team_core.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "03e9405c518c4d61f28079492f252d6d4e2bac5c",
              "status": "affected",
              "version": "3d249d4ca7d0ed6629a135ea1ea21c72286c0d80",
              "versionType": "git"
            },
            {
              "lessThan": "25fe708bbc59289d3d1ea4b126fbc1b460a072a5",
              "status": "affected",
              "version": "3d249d4ca7d0ed6629a135ea1ea21c72286c0d80",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/net/team/team_core.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "3.3"
            },
            {
              "lessThan": "3.3",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.35",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "07BA7427-9CE4-4A52-8983-5A2B47E91E3A",
              "versionEndExcluding": "6.18.35",
              "versionStartIncluding": "3.3",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "0F56D2D7-70AB-4452-A0E3-BDA402CF049E",
              "versionEndExcluding": "7.1",
              "versionStartIncluding": "6.19",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:*",
              "matchCriteriaId": "B1EF7059-E670-45F4-B422-54C40FA86390",
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              "matchCriteriaId": "EC732D08-5F7B-46D9-B154-E60C7F4F0A97",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:*",
              "matchCriteriaId": "E5910A9D-F60A-409A-B486-FE66BFEBA9B9",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc5:*:*:*:*:*:*",
              "matchCriteriaId": "81DFF19E-9CF8-49C6-8C36-1E4038622933",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: team: fix NULL pointer dereference in team_xmit during mode change\n\n__team_change_mode() clears team-\u003eops with memset() before restoring\nsafe dummy handlers via team_adjust_ops(). A concurrent team_xmit()\nrunning under RCU on another CPU can read team-\u003eops.transmit during\nthis window and call a NULL function pointer, crashing the kernel.\n\nThe race requires a mode change (CAP_NET_ADMIN) concurrent with\ntransmit on the team device.\n\n BUG: kernel NULL pointer dereference, address: 0000000000000000\n Oops: 0010 [#1] SMP KASAN NOPTI\n RIP: 0010:0x0\n Call Trace:\n  team_xmit (drivers/net/team/team_core.c:1853)\n  dev_hard_start_xmit (net/core/dev.c:3904)\n  __dev_queue_xmit (net/core/dev.c:4871)\n  packet_sendmsg (net/packet/af_packet.c:3109)\n  __sys_sendto (net/socket.c:2265)\n\nThe original code assumed that no ports means no traffic, so mode\nchanges could freely memset()/memcpy() the ops.  AF_PACKET with\nforced carrier breaks that assumption.\n\nPrevent the race instead of making it safe: replace memset()/memcpy()\nwith per-field updates that never touch transmit or receive.  Those\ntwo handlers are managed solely by team_adjust_ops(), which already\ninstalls dummies when tx_en_port_count == 0 (always true during mode\nchange since no ports are present).  WRITE_ONCE/READ_ONCE prevent\nstore/load tearing on the handler pointers.\n\nsynchronize_net() before exit_op() drains in-flight readers that may\nstill reference old mode state from before port removal switched the\nhandlers to dummies."
    }
  ],
  "id": "CVE-2026-64190",
  "lastModified": "2026-08-11T19:06:38.500",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 5.5,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 3.6,
        "source": "nvd@nist.gov",
        "type": "Primary"
      }
    ]
  },
  "published": "2026-07-20T17:18:22.117",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/03e9405c518c4d61f28079492f252d6d4e2bac5c"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/25fe708bbc59289d3d1ea4b126fbc1b460a072a5"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-476"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}



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