{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "bd54df5ea7cadac520e346d5f0fe5d58e635b6ba"
            },
            {
              "fixed": "4a7e941ca29a608c6244cbd028d3599ecaef7207"
            },
            {
              "fixed": "19b4be0717fa83265d66aea836b7022d898422cf"
            },
            {
              "fixed": "8e7ff730dd96519a333d1570edf1c3fabb6d3629"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "6.16.0"
            },
            {
              "fixed": "6.18.46"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.1.11"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/80xxx/CVE-2026-80776.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nfutex: Fix race in futex_pivot_pending() during private hash resize\n\nA task performing a custom private hash resize can remain blocked in\nuninterruptible sleep indefinitely.  The hung-task detector reports:\n\n  INFO: task futex-resizer:314 blocked for more than 10 seconds.\n  task:futex-resizer state:D stack:14824 pid:314 tgid:312 ppid:311\n\n  Call Trace:\n   __schedule+0x521/0xf30\n   schedule+0x22/0xa0\n   futex_hash_allocate+0x3db/0x490\n   __do_sys_prctl+0x6f5/0xbd0\n   do_syscall_64+0xf9/0x530\n   entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\n  Kernel panic - not syncing: hung_task: blocked tasks\n\nfutex_pivot_pending() allows the resize request to continue when\neither no replacement hash is pending (hash_new == NULL) or the current\nhash reference count has reached zero.\n\nAfter the final-reference wake, another futex task can complete the\npivot between the two observations:\n\n  T1                                  T2\n\n  futex_hash_allocate()\n    wait_var_event(mm, ...)\n      futex_pivot_pending(mm)\n        hash_new != NULL\n                                      futex_hash()\n                                        futex_ref_get(old) -\u003e false\n                                        futex_pivot_hash(mm)\n                                          hash_new = NULL\n                                          __futex_pivot_hash(mm, new)\n                                            rcu_assign_pointer(hash, new)\n        fph = rcu_dereference(hash) /* new */\n        futex_ref_is_dead(fph) -\u003e false\n      schedule()\n\nThe pivot changes the state from hash_new != NULL with a dead current\nhash to hash_new == NULL with a live current hash.  Because\nfutex_pivot_pending() reads hash_new and hash without serialization,\nthe resize task can observe hash_new in the pre-pivot state and hash in\nthe post-pivot state, causing futex_pivot_pending() to return false even\nthough the pivot has completed.  The task then goes to sleep after the\nwakeup has already been consumed.\n\nSerialize state reads in futex_pivot_pending() using futex_mm_phash::lock.\nThis guarantees that futex_pivot_pending() observes hash_new and hash\natomically, eliminating the race condition.",
  "id": "CVE-2026-80776",
  "modified": "2026-09-06T03:30:50.338377529Z",
  "published": "2026-09-04T15:12:48.314Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/19b4be0717fa83265d66aea836b7022d898422cf"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/4a7e941ca29a608c6244cbd028d3599ecaef7207"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/8e7ff730dd96519a333d1570edf1c3fabb6d3629"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/80xxx/CVE-2026-80776.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-80776"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.9.0",
  "summary": "futex: Fix race in futex_pivot_pending() during private hash resize"
}