CVE-2026-31474 (GCVE-0-2026-31474)

Vulnerability from cvelistv5 – Published: 2026-04-22 13:54 – Updated: 2026-04-22 13:54
VLAI?
Title
can: isotp: fix tx.buf use-after-free in isotp_sendmsg()
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.
Severity ?
No CVSS data available.
Assigner
References
Impacted products
Vendor Product Version
Linux Linux Affected: 96d1c81e6a0478535342dff6c730adb076cd84e8 , < cb3d6efa78460e6d50bf68806d0db66265709f64 (git)
Affected: 96d1c81e6a0478535342dff6c730adb076cd84e8 , < 9649d051e54413049c009638ec1dc23962c884a4 (git)
Affected: 96d1c81e6a0478535342dff6c730adb076cd84e8 , < eec8a1b18a79600bd4419079dc0026c1db72a830 (git)
Affected: 96d1c81e6a0478535342dff6c730adb076cd84e8 , < 2e62e7051eca75a7f2e3d52d62ec10d7d7aa358c (git)
Affected: 96d1c81e6a0478535342dff6c730adb076cd84e8 , < 424e95d62110cdbc8fd12b40918f37e408e35a92 (git)
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    Linux Linux Affected: 6.4
Unaffected: 0 , < 6.4 (semver)
Unaffected: 6.6.131 , ≤ 6.6.* (semver)
Unaffected: 6.12.80 , ≤ 6.12.* (semver)
Unaffected: 6.18.21 , ≤ 6.18.* (semver)
Unaffected: 6.19.11 , ≤ 6.19.* (semver)
Unaffected: 7.0 , ≤ * (original_commit_for_fix)
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{
  "containers": {
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      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/can/isotp.c"
          ],
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          "vendor": "Linux",
          "versions": [
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              "status": "unaffected",
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              "versionType": "semver"
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              "versionType": "semver"
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              "status": "unaffected",
              "version": "6.18.21",
              "versionType": "semver"
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            {
              "lessThanOrEqual": "6.19.*",
              "status": "unaffected",
              "version": "6.19.11",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.0",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
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                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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                  "vulnerable": true
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                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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                  "versionStartIncluding": "6.4",
                  "vulnerable": true
                },
                {
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              "negate": false,
              "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."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-04-22T13:54:03.100Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
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          "url": "https://git.kernel.org/stable/c/cb3d6efa78460e6d50bf68806d0db66265709f64"
        },
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          "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()",
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        "engine": "bippy-1.2.0"
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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": "2026-04-22T13:54:03.100Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-31474\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-04-22T14:16:44.053\",\"lastModified\":\"2026-04-22T14:16:44.053\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"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\":{},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/2e62e7051eca75a7f2e3d52d62ec10d7d7aa358c\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/424e95d62110cdbc8fd12b40918f37e408e35a92\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/9649d051e54413049c009638ec1dc23962c884a4\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/cb3d6efa78460e6d50bf68806d0db66265709f64\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/eec8a1b18a79600bd4419079dc0026c1db72a830\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}"
  }
}


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