CVE-2026-31474 (GCVE-0-2026-31474)
Vulnerability from cvelistv5
Published
2026-04-22 13:54
Modified
2026-04-27 14:03
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: 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.
References
Impacted products
Vendor Product Version
Linux Linux Version: 96d1c81e6a0478535342dff6c730adb076cd84e8
Version: 96d1c81e6a0478535342dff6c730adb076cd84e8
Version: 96d1c81e6a0478535342dff6c730adb076cd84e8
Version: 96d1c81e6a0478535342dff6c730adb076cd84e8
Version: 96d1c81e6a0478535342dff6c730adb076cd84e8
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{
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      ],
      "cpeApplicability": [
        {
          "nodes": [
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              "cpeMatch": [
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              "operator": "OR"
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      "descriptions": [
        {
          "lang": "en",
          "value": "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."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          }
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-04-27T14:03:28.176Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
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          "url": "https://git.kernel.org/stable/c/cb3d6efa78460e6d50bf68806d0db66265709f64"
        },
        {
          "url": "https://git.kernel.org/stable/c/9649d051e54413049c009638ec1dc23962c884a4"
        },
        {
          "url": "https://git.kernel.org/stable/c/eec8a1b18a79600bd4419079dc0026c1db72a830"
        },
        {
          "url": "https://git.kernel.org/stable/c/2e62e7051eca75a7f2e3d52d62ec10d7d7aa358c"
        },
        {
          "url": "https://git.kernel.org/stable/c/424e95d62110cdbc8fd12b40918f37e408e35a92"
        }
      ],
      "title": "can: isotp: fix tx.buf use-after-free in isotp_sendmsg()",
      "x_generator": {
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  "cveMetadata": {
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    "assignerShortName": "Linux",
    "cveId": "CVE-2026-31474",
    "datePublished": "2026-04-22T13:54:03.100Z",
    "dateReserved": "2026-03-09T15:48:24.098Z",
    "dateUpdated": "2026-04-27T14:03:28.176Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


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