{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "c4b28963fd79457315783b3b0f21c01eb88cfdc1"
            },
            {
              "fixed": "9a1b12c06c192290b8479de48f66f1e75d89c4b7"
            },
            {
              "fixed": "3fc8044251de21555fb02c365fa681bab8b0db55"
            },
            {
              "fixed": "1838c704bcb4fd3556cf67513c6f97a39099e35c"
            },
            {
              "fixed": "5d10d4e19e6daa487f0cd0ea6cba472325de92f9"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "5.10.0"
            },
            {
              "fixed": "6.12.109"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.50"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.2.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89759.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/kmemleak: avoid soft lockup when scanning task stacks\n\nPatch series \"mm/kmemleak: avoid soft lockup when scanning task\", v3.\n\nkmemleak_scan() scans every task stack under one rcu_read_lock() with no\nreschedule point, which can trip the soft lockup watchdog on hosts with\nvery many threads.\n\nThat prints the following message, depending on the workload+host\nconfiguration:\n\n      watchdog: BUG: soft lockup - CPU#35 stuck for 22s! [kmemleak:537]\n       scan_block\n       kmemleak_scan\n       kmemleak_scan_thread\n       kthread\n\nPatch 1 walks the tasks with find_ge_pid() so the scan reschedules between\ntasks\n\nPatches 2-3 let the scan loops stop early once a scan is interrupted.\n\n\nThis patch (of 3):\n\nkmemleak_scan() walks every thread and scans its kernel stack under a\nsingle rcu_read_lock() with no reschedule point.  On a host with very many\nthreads -- amplified by KASAN/lockdep in debug builds -- this loop can hog\na CPU long enough to trip the soft lockup watchdog:\n\n  watchdog: BUG: soft lockup - CPU#35 stuck for 22s! [kmemleak:537]\n   scan_block\n   kmemleak_scan\n   kmemleak_scan_thread\n   kthread\n\nA cond_resched() cannot be added directly: the loop runs inside an RCU\nread-side critical section.\n\nWalk the tasks one PID at a time with find_ge_pid(), taking the RCU read\nlock only to look up and pin each task.  The stack is then scanned with no\nlock held, so cond_resched() runs between tasks and the scan stops early\non scan_should_stop().  This follows the next_tgid()/task_seq_get_next()\niteration pattern and keeps each RCU critical section short.",
  "id": "CVE-2026-89759",
  "modified": "2026-09-13T03:30:37.263780785Z",
  "published": "2026-09-11T19:47:01.313Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/1838c704bcb4fd3556cf67513c6f97a39099e35c"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/3fc8044251de21555fb02c365fa681bab8b0db55"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/5d10d4e19e6daa487f0cd0ea6cba472325de92f9"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/9a1b12c06c192290b8479de48f66f1e75d89c4b7"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89759.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-89759"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.9.0",
  "summary": "mm/kmemleak: avoid soft lockup when scanning task stacks"
}