{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "include/linux/mm_types.h",
            "include/linux/sched.h",
            "kernel/exit.c",
            "kernel/sched/fair.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "852ecb6bc0bc0106f44f74ba3944524732486025",
              "status": "affected",
              "version": "df0d98475954d655571979aa061ecb07d7e00392",
              "versionType": "git"
            },
            {
              "lessThan": "28f9c0e0a0b94c5d3e1b634db545f6e1f94858c5",
              "status": "affected",
              "version": "df0d98475954d655571979aa061ecb07d7e00392",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "include/linux/mm_types.h",
            "include/linux/sched.h",
            "kernel/exit.c",
            "kernel/sched/fair.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "7.2"
            },
            {
              "lessThan": "7.2",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.9",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.9",
                  "versionStartIncluding": "7.2",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3",
                  "versionStartIncluding": "7.2",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsched/cache: Decouple sched_cache_group from mm to fix UAF\n\nCurrently the sched cache grouping is by mm and the scheduling statistics\nsched_cache_stat lives in the mm structure.  This ties the life cycle\nof scheduling stats with mm.\n\nIn account_mm_sched(), the scheduling stats are accessed by\ntask-\u003emm-\u003esc_stat.  However, a task may be switching mm on one CPU when\nanother CPU is running account_mm_sched(), and possibly accessing the\nold mm that was freed.  This problem was found when running tests with\nKASAN by Hyunwoo:\n\n  https://lore.kernel.org/lkml/apPb-Dr4nPYuHQOK@v4bel/\n\nInstead of serializing the mm access by introducing extra acquisition of\nrq lock in the mm free path, extract sched_cache_stat from mm_struct,\nrename it as sched_cache_group and manage its life cycle apart from\nmm_struct with its own ref counting.  This allows us in the next patch\naccess sched_cache_group directly from task, and add a refcount\non sched_cache_group when a task links to it. This prevents the use\nafter free issue when accessing stale and released old mm and its\nsched cache stat a task switches to a new mm while account_mm_sched()\nis done elsewhere.\n\nThe other benefit of this restructure is in the future, the grouping of\ntasks to a LLC would have the flexibility to be associated with a user\ndefined grouping, or cgroup, cookie group, numa_group or others instead\nof just with a single mm address space.\n\nRename sched_cache_stat to sched_cache_group and turn it into a refcounted\nobject allocated from mm_struct.  The mm_struct now holds a pointer\n(sched_cache_grp) to this object instead of embedding it."
        }
      ],
      "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 - An unprivileged local write(2) to an attacker-created pipe reaches anon_pipe_write()-\u003etry_to_wake_up()-\u003ettwu_queue()-\u003eenqueue_task_fair()-\u003eupdate_curr()-\u003eupdate_se()-\u003eaccount_mm_sched(), while the attacker\u0027s execveat(2) frees rq-\u003ecurr\u0027s old mm. No protocol supplies the trigger.\nAC:L - On a qualifying multi-LLC SMP host, CONFIG_SCHED_CACHE and sysctl_sched_cache_user both default enabled. The attacker controls both race sides by repeatedly waking or updating its queued task and execveat()ing its pinned trampoline, and can groom the freed per-CPU slot.\nPR:L - user_check_sched_setscheduler() permits the same-owner SCHED_IDLE/lower-priority sched_setattr() used to force update_curr() without CAP_SYS_NICE; pipe creation, permitted CPU affinity, and execveat() of the attacker\u0027s memfd also require no capability.\nUI:N - The attacker creates the pipe and tasks, drives sched_setattr() or write(), and calls execveat() to replace and release its own mm; no other user must mount, open, or approve anything.\nS:U - account_mm_sched() and mm_destroy_sched() are host-kernel scheduler/mm code, and the demonstrated result is UID-0 execution under that same kernel authority, not a guest-to-host or IOMMU boundary crossing.\nC:H - After mm_destroy_sched() frees sc_stat.pcpu_sched, __update_mm_sched() accesses its reclaimed epoch and runtime. The demonstrated reclaim corrupts a futex reference and reaches UID 0 through pipe/page-cache manipulation, enabling unrestricted data reads.\nI:H - The stale pcpu_sched-\u003eepoch write changes a reclaimed futex per-CPU reference from 1 to 0; the demonstrated follow-on UAF decrements pipe_buffer.flags, enables page-cache overwrite of /usr/bin/newgrp, and executes as UID 0.\nA:H - __update_mm_sched() and pcpu_sched-\u003eruntime += delta_exec access freed per-CPU storage; if reclamation is not steered, these writes can corrupt reused kernel objects and cause an oops or panic."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-24T14:08:42.034Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/852ecb6bc0bc0106f44f74ba3944524732486025"
        },
        {
          "url": "https://git.kernel.org/stable/c/28f9c0e0a0b94c5d3e1b634db545f6e1f94858c5"
        }
      ],
      "title": "sched/cache: Decouple sched_cache_group from mm to fix UAF",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-98385",
    "datePublished": "2026-10-12T05:48:52.248Z",
    "dateReserved": "2026-09-25T10:25:14.345Z",
    "dateUpdated": "2026-10-24T14:08:42.034Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}