Vulnerability-Lookup

GHSA-FG66-CP5R-9M26

Vulnerability from github – Published: 2026-07-20 18:32 – Updated: 2026-07-20 18:32

Details

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.

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{
  "affected": [],
  "aliases": [
    "CVE-2026-64190"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-07-20T17:18:22Z",
    "severity": null
  },
  "details": "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": "GHSA-fg66-cp5r-9m26",
  "modified": "2026-07-20T18:32:33Z",
  "published": "2026-07-20T18:32:33Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-64190"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/03e9405c518c4d61f28079492f252d6d4e2bac5c"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/25fe708bbc59289d3d1ea4b126fbc1b460a072a5"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

CVE-2026-64190 (GCVE-0-2026-64190)

Vulnerability from cvelistv5 – Published: 2026-07-20 16:27 – Updated: 2026-07-20 16:27

Title

net: team: fix NULL pointer dereference in team_xmit during mode change

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.

Severity

No CVSS data available.

Assigner

Linux

References

2 references

URL	Tags
https://git.kernel.org/stable/c/03e9405c518c4d61f…
https://git.kernel.org/stable/c/25fe708bbc59289d3…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 3d249d4ca7d0ed6629a135ea1ea21c72286c0d80 , < 03e9405c518c4d61f28079492f252d6d4e2bac5c (git) Affected: 3d249d4ca7d0ed6629a135ea1ea21c72286c0d80 , < 25fe708bbc59289d3d1ea4b126fbc1b460a072a5 (git)
Linux	Linux	Affected: 3.3 Unaffected: 0 , < 3.3 (semver) Unaffected: 6.18.35 , ≤ 6.18.* (semver) Unaffected: 7.1 , ≤ * (original_commit_for_fix)

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "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"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.35",
                  "versionStartIncluding": "3.3",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1",
                  "versionStartIncluding": "3.3",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "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."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-07-20T16:27:48.314Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/03e9405c518c4d61f28079492f252d6d4e2bac5c"
        },
        {
          "url": "https://git.kernel.org/stable/c/25fe708bbc59289d3d1ea4b126fbc1b460a072a5"
        }
      ],
      "title": "net: team: fix NULL pointer dereference in team_xmit during mode change",
      "x_generator": {
        "engine": "bippy-1.2.0"
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  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-64190",
    "datePublished": "2026-07-20T16:27:48.314Z",
    "dateReserved": "2026-07-19T07:54:57.040Z",
    "dateUpdated": "2026-07-20T16:27:48.314Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.

Action not permitted

GHSA-FG66-CP5R-9M26

CVE-2026-64190 (GCVE-0-2026-64190)

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Nomenclature