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FKIE_CVE-2026-74594

Vulnerability from fkie_nvd - Published: 2026-08-22 16:16 - Updated: 2026-08-25 06:18
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: sched/psi: Shut down rtpoll_timer in psi_cgroup_free() psi_schedule_rtpoll_work() is called locklessly from the scheduler hotpath and can race psi_trigger_destroy() taking down the last rtpoll trigger under rtpoll_trigger_lock: psi_schedule_rtpoll_work() psi_trigger_destroy() rcu_read_lock(); task = rcu_dereference(rtpoll_task); rcu_assign_pointer(rtpoll_task, NULL); timer_delete(&rtpoll_timer); mod_timer(&rtpoll_timer, ...); rcu_read_unlock(); synchronize_rcu(); kthread_stop(task_to_destroy); The group can then be freed with the re-armed timer still pending, and poll_timer_fn() runs on freed memory. 461daba06bdc ("psi: eliminate kthread_worker from psi trigger scheduling mechanism") deleted the timer synchronously after the synchronize_rcu(), which prevented this but raced trigger creation instead: the deletion could cancel the timer that a new trigger set armed during the grace period and, as creation also reinitialized the timer at the time, corrupt it. 8f91efd870ea ("psi: Fix race between psi_trigger_create/destroy") moved the initialization into group_init() and the deletion into the locked section, trading the creation races for the window above. Neither placement in the destruction path works. A pending timer firing while the group is alive is harmless though. poll_timer_fn() just wakes the rtpoll waitqueue and doesn't re-arm itself. Bind the timer to the group's lifetime instead and shut it down in psi_cgroup_free(). Nothing can arm it by then. timer_shutdown_sync() because the timer is never armed again.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/1e5ca82eee59caca6988f9d6e859786aab8a5fa0
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/310b5a537a78c358a4cd244bd767c1a517a05459
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/4addb102154b7cf6e2310ccbe20c3c08619e520d
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/5457025fa8ca3c0d2732109513de839e3e797190
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/611e7821c4f83a671455658797336faecc3a5196
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/8037c5b2b2a447df52542f4d8535895d837bdcbd
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/806fcff98c1d7cb3c1dc0015e55ebdbe819e6b08
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/894a9300d7fb2e2951da92e565ae6de7ddfb0a69
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "kernel/sched/psi.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "4addb102154b7cf6e2310ccbe20c3c08619e520d",
              "status": "affected",
              "version": "6bfcb6178925b1fd28c102e53d403091b8f49396",
              "versionType": "git"
            },
            {
              "lessThan": "894a9300d7fb2e2951da92e565ae6de7ddfb0a69",
              "status": "affected",
              "version": "8f91efd870ea5d8bc10b0fcc9740db51cd4c0c83",
              "versionType": "git"
            },
            {
              "lessThan": "1e5ca82eee59caca6988f9d6e859786aab8a5fa0",
              "status": "affected",
              "version": "8f91efd870ea5d8bc10b0fcc9740db51cd4c0c83",
              "versionType": "git"
            },
            {
              "lessThan": "310b5a537a78c358a4cd244bd767c1a517a05459",
              "status": "affected",
              "version": "8f91efd870ea5d8bc10b0fcc9740db51cd4c0c83",
              "versionType": "git"
            },
            {
              "lessThan": "806fcff98c1d7cb3c1dc0015e55ebdbe819e6b08",
              "status": "affected",
              "version": "8f91efd870ea5d8bc10b0fcc9740db51cd4c0c83",
              "versionType": "git"
            },
            {
              "lessThan": "8037c5b2b2a447df52542f4d8535895d837bdcbd",
              "status": "affected",
              "version": "8f91efd870ea5d8bc10b0fcc9740db51cd4c0c83",
              "versionType": "git"
            },
            {
              "lessThan": "611e7821c4f83a671455658797336faecc3a5196",
              "status": "affected",
              "version": "8f91efd870ea5d8bc10b0fcc9740db51cd4c0c83",
              "versionType": "git"
            },
            {
              "lessThan": "5457025fa8ca3c0d2732109513de839e3e797190",
              "status": "affected",
              "version": "8f91efd870ea5d8bc10b0fcc9740db51cd4c0c83",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "e1e5e263bbe0e6e9c3db36aa48a3c8acf546fa49",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "979965c33f734a1666af67900408f997ac669c23",
              "versionType": "git"
            },
            {
              "lessThan": "5.10.266",
              "status": "affected",
              "version": "5.10.50",
              "versionType": "semver"
            },
            {
              "lessThan": "5.13",
              "status": "affected",
              "version": "5.12.17",
              "versionType": "semver"
            },
            {
              "lessThan": "5.14",
              "status": "affected",
              "version": "5.13.2",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "kernel/sched/psi.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.14"
            },
            {
              "lessThan": "5.14",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.266",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.217",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.183",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.152",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.104",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.45",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.9",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsched/psi: Shut down rtpoll_timer in psi_cgroup_free()\n\npsi_schedule_rtpoll_work() is called locklessly from the scheduler hotpath\nand can race psi_trigger_destroy() taking down the last rtpoll trigger under\nrtpoll_trigger_lock:\n\n  psi_schedule_rtpoll_work()        psi_trigger_destroy()\n\n  rcu_read_lock();\n  task = rcu_dereference(rtpoll_task);\n                                    rcu_assign_pointer(rtpoll_task, NULL);\n                                    timer_delete(\u0026rtpoll_timer);\n  mod_timer(\u0026rtpoll_timer, ...);\n  rcu_read_unlock();\n                                    synchronize_rcu();\n                                    kthread_stop(task_to_destroy);\n\nThe group can then be freed with the re-armed timer still pending, and\npoll_timer_fn() runs on freed memory.\n\n461daba06bdc (\"psi: eliminate kthread_worker from psi trigger scheduling\nmechanism\") deleted the timer synchronously after the synchronize_rcu(),\nwhich prevented this but raced trigger creation instead: the deletion could\ncancel the timer that a new trigger set armed during the grace period and,\nas creation also reinitialized the timer at the time, corrupt it.\n8f91efd870ea (\"psi: Fix race between psi_trigger_create/destroy\") moved the\ninitialization into group_init() and the deletion into the locked section,\ntrading the creation races for the window above.\n\nNeither placement in the destruction path works. A pending timer firing\nwhile the group is alive is harmless though. poll_timer_fn() just wakes the\nrtpoll waitqueue and doesn\u0027t re-arm itself. Bind the timer to the group\u0027s\nlifetime instead and shut it down in psi_cgroup_free(). Nothing can arm it\nby then. timer_shutdown_sync() because the timer is never armed again."
    }
  ],
  "id": "CVE-2026-74594",
  "lastModified": "2026-08-25T06:18:34.890",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 7.8,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.9,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-08-22T16:16:31.680",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/1e5ca82eee59caca6988f9d6e859786aab8a5fa0"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/310b5a537a78c358a4cd244bd767c1a517a05459"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/4addb102154b7cf6e2310ccbe20c3c08619e520d"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/5457025fa8ca3c0d2732109513de839e3e797190"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/611e7821c4f83a671455658797336faecc3a5196"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/8037c5b2b2a447df52542f4d8535895d837bdcbd"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/806fcff98c1d7cb3c1dc0015e55ebdbe819e6b08"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/894a9300d7fb2e2951da92e565ae6de7ddfb0a69"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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