CVE-2026-64375 (GCVE-0-2026-64375)
Vulnerability from cvelistv5
Published
2026-07-25 08:50
Modified
2026-08-17 04:54
Summary
In the Linux kernel, the following vulnerability has been resolved: proc: protect ptrace_may_access() with exec_update_lock (FD links) proc_pid_get_link() and proc_pid_readlink() currently look up the task from the pid once, then do the ptrace access check on that task, then look up the task from the pid a second time to do the actual access. That's racy in several ways. To fix it, pass the task to the ->proc_get_link() handler, and instead of proc_fd_access_allowed(), introduce a new helper call_proc_get_link() that looks up and locks the task, does the access check, and calls ->proc_get_link().
Impacted products
Vendor Product Version
Linux Linux Version: 778c1144771f0064b6f51bee865cceb0d996f2f9
Version: 778c1144771f0064b6f51bee865cceb0d996f2f9
Version: 778c1144771f0064b6f51bee865cceb0d996f2f9
Version: 778c1144771f0064b6f51bee865cceb0d996f2f9
Version: 778c1144771f0064b6f51bee865cceb0d996f2f9
Version: 778c1144771f0064b6f51bee865cceb0d996f2f9
Version: 778c1144771f0064b6f51bee865cceb0d996f2f9
Version: 778c1144771f0064b6f51bee865cceb0d996f2f9
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/proc/base.c",
            "fs/proc/fd.c",
            "fs/proc/internal.h"
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          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
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          "product": "Linux",
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            "fs/proc/fd.c",
            "fs/proc/internal.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
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              "status": "affected",
              "version": "2.6.18"
            },
            {
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              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.261",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.212",
              "versionType": "semver"
            },
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              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.178",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.145",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.97",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.40",
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            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.10.261",
                  "versionStartIncluding": "2.6.18",
                  "vulnerable": true
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                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.15.212",
                  "versionStartIncluding": "2.6.18",
                  "vulnerable": true
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                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.1.178",
                  "versionStartIncluding": "2.6.18",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.145",
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                  "vulnerable": true
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                {
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                {
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                  "vulnerable": true
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                  "vulnerable": true
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                {
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                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nproc: protect ptrace_may_access() with exec_update_lock (FD links)\n\nproc_pid_get_link() and proc_pid_readlink() currently look up the task from\nthe pid once, then do the ptrace access check on that task, then look up\nthe task from the pid a second time to do the actual access.\nThat\u0027s racy in several ways.\n\nTo fix it, pass the task to the -\u003eproc_get_link() handler, and instead of\nproc_fd_access_allowed(), introduce a new helper call_proc_get_link() that\nlooks up and locks the task, does the access check, and calls\n-\u003eproc_get_link()."
        }
      ],
      "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"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - Exploitation uses local open/openat or readlink syscalls against /proc/$pid symlinks; no network or physical access path reaches the flaw.\nAC:L - The attacker can launch the setuid target process and race concurrent procfs accesses repeatedly, thereby controlling both sides of the race.\nPR:L - A basic unprivileged user can pass the initial ptrace check against a same-UID dumpable child before it performs privileged exec; no capability is required.\nUI:N - The attacker can create and race the target by launching the setuid program directly, without action from another user.\nS:U - The procfs authorization bypass compromises privileged resources on the same host and constitutes ordinary local privilege escalation rather than crossing a VM or hardware isolation boundary.\nC:H - The race can redirect an authorized pre-exec lookup to a private post-setuid memfd whose permissive shmem inode allows the attacker to read all privileged contents, including secrets.\nI:H - The attacker can obtain write and truncation access to the privileged memfd; corruption of trusted data or executable content consumed by the setuid process can yield root-level code execution.\nA:H - Tampering with a privileged process\u0027s trusted memfd can crash or disable critical privileged services, and resulting root-level execution permits complete system availability loss."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-17T04:54:26.202Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/6253dfee5afba536bb54fc6fe6c091c3758fafe1"
        },
        {
          "url": "https://git.kernel.org/stable/c/65bf0d2b6e914f1448d6a2fde193dcf60936a651"
        },
        {
          "url": "https://git.kernel.org/stable/c/de497d7aa2fae453a7e7c8f7d3e8682e565e3aaf"
        },
        {
          "url": "https://git.kernel.org/stable/c/138c692d2b2d63d26f2eb957d0e4fcc5d61f9ff2"
        },
        {
          "url": "https://git.kernel.org/stable/c/83b17872e3166c295c599279fc9562ac3840c638"
        },
        {
          "url": "https://git.kernel.org/stable/c/497c6bae5167428596575f20af6613ff5671f383"
        },
        {
          "url": "https://git.kernel.org/stable/c/dfd1894cb64cbd8758b461ed713800fe73db4f82"
        },
        {
          "url": "https://git.kernel.org/stable/c/6255da28d4bb5349fe18e84cb043ccd394eba75d"
        }
      ],
      "title": "proc: protect ptrace_may_access() with exec_update_lock (FD links)",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-64375",
    "datePublished": "2026-07-25T08:50:26.869Z",
    "dateReserved": "2026-07-19T15:36:31.784Z",
    "dateUpdated": "2026-08-17T04:54:26.202Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


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  • Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
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