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GHSA-6P7X-C5RV-9W7V

Vulnerability from github – Published: 2026-04-22 15:31 – Updated: 2026-06-30 03:36
VLAI
Details

In the Linux kernel, the following vulnerability has been resolved:

can: isotp: fix tx.buf use-after-free in isotp_sendmsg()

isotp_sendmsg() uses only cmpxchg() on so->tx.state to serialize access to so->tx.buf. isotp_release() waits for ISOTP_IDLE via wait_event_interruptible() and then calls kfree(so->tx.buf).

If a signal interrupts the wait_event_interruptible() inside close() while tx.state is ISOTP_SENDING, the loop exits early and release proceeds to force ISOTP_SHUTDOWN and continues to kfree(so->tx.buf) while sendmsg may still be reading so->tx.buf for the final CAN frame in isotp_fill_dataframe().

The so->tx.buf can be allocated once when the standard tx.buf length needs to be extended. Move the kfree() of this potentially extended tx.buf to sk_destruct time when either isotp_sendmsg() and isotp_release() are done.

Severity
7.8 (High)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
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{
  "affected": [],
  "aliases": [
    "CVE-2026-31474"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-364",
      "CWE-416"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-04-22T14:16:44Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\ncan: isotp: fix tx.buf use-after-free in isotp_sendmsg()\n\nisotp_sendmsg() uses only cmpxchg() on so-\u003etx.state to serialize access\nto so-\u003etx.buf. isotp_release() waits for ISOTP_IDLE via\nwait_event_interruptible() and then calls kfree(so-\u003etx.buf).\n\nIf a signal interrupts the wait_event_interruptible() inside close()\nwhile tx.state is ISOTP_SENDING, the loop exits early and release\nproceeds to force ISOTP_SHUTDOWN and continues to kfree(so-\u003etx.buf)\nwhile sendmsg may still be reading so-\u003etx.buf for the final CAN frame\nin isotp_fill_dataframe().\n\nThe so-\u003etx.buf can be allocated once when the standard tx.buf length needs\nto be extended. Move the kfree() of this potentially extended tx.buf to\nsk_destruct time when either isotp_sendmsg() and isotp_release() are done.",
  "id": "GHSA-6p7x-c5rv-9w7v",
  "modified": "2026-06-30T03:36:22Z",
  "published": "2026-04-22T15:31:42Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-31474"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:27288"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:27731"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:27789"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/security/cve/CVE-2026-31474"
    },
    {
      "type": "WEB",
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2460646"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2e62e7051eca75a7f2e3d52d62ec10d7d7aa358c"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/424e95d62110cdbc8fd12b40918f37e408e35a92"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/9649d051e54413049c009638ec1dc23962c884a4"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/cb3d6efa78460e6d50bf68806d0db66265709f64"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/eec8a1b18a79600bd4419079dc0026c1db72a830"
    },
    {
      "type": "WEB",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-31474.json"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}



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