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CVE-2026-64190

Full vulnerability record from the local CVENow database.

Description

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.

Severity
MEDIUM
CVSS score
5.5 (v3.1)
Vulnerability status
Modified
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-07-20 17:18:22.117000
Last modified
2026-10-30 13:19:33.157000
View original CVE JSON 
{
  "id": "CVE-2026-64190",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-07-20T17:18:22.117",
  "lastModified": "2026-10-30T13:19:33.157",
  "vulnStatus": "Modified",
  "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->ops with memset() before restoring\nsafe dummy handlers via team_adjust_ops(). A concurrent team_xmit()\nrunning under RCU on another CPU can read team->ops.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."
    }
  ],
  "affected": [
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      "affectedData": [
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          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
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          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
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        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "drivers/net/team/team_core.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
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              "version": "3.3",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "3.3",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "5.10.273",
              "lessThanOrEqual": "5.10.*",
              "versionType": "semver",
              "status": "unaffected"
            },
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              "version": "5.15.224",
              "lessThanOrEqual": "5.15.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.1.191",
              "lessThanOrEqual": "6.1.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.6.160",
              "lessThanOrEqual": "6.6.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.12.114",
              "lessThanOrEqual": "6.12.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.35",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.1",
              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "[email protected]",
        "type": "Primary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
          "baseScore": 5.5,
          "baseSeverity": "MEDIUM",
          "attackVector": "LOCAL",
          "attackComplexity": "LOW",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 3.6
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Primary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-476"
        }
      ]
    }
  ],
  "configurations": [
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          "negate": false,
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  "references": [
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      "url": "https://git.kernel.org/stable/c/03e9405c518c4d61f28079492f252d6d4e2bac5c",
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}