CVE-2026-80776
In the Linux kernel, the following vulnerability has been resolved:
futex: Fix race in futex_pivot_pending() during private hash resize
A task performing a custom private hash resize can remain blocked in uninterruptible sleep indefinitely. The hung-task detector reports:
futex_pivot_pending() allows the resize request to continue when either no replacement hash is pending (hash_new == NULL) or the current hash reference count has reached zero.
After the final-reference wake, another futex task can complete the pivot between the two observations:
The pivot changes the state from hash_new != NULL with a dead current hash to hash_new == NULL with a live current hash.
Leer descripción completaMostrar menos
Because futex_pivot_pending() reads hash_new and hash without serialization, the resize task can observe hash_new in the pre-pivot state and hash in the post-pivot state, causing futex_pivot_pending() to return false even though the pivot has completed. The task then goes to sleep after the wakeup has already been consumed.
Serialize state reads in futex_pivot_pending() using futex_mm_phash::lock. This guarantees that futex_pivot_pending() observes hash_new and hash atomically, eliminating the race condition.
Detalles técnicos trazas, registros y código del informe original
INFO: task futex-resizer:314 blocked for more than 10 seconds.
task:futex-resizer state:D stack:14824 pid:314 tgid:312 ppid:311
Call Trace:
__schedule+0x521/0xf30
schedule+0x22/0xa0
futex_hash_allocate+0x3db/0x490
__do_sys_prctl+0x6f5/0xbd0
do_syscall_64+0xf9/0x530
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Kernel panic - not syncing: hung_task: blocked tasks
T1 T2
futex_hash_allocate()
wait_var_event(mm, ...)
futex_pivot_pending(mm)
hash_new != NULL
futex_hash()
futex_ref_get(old) -> false
futex_pivot_hash(mm)
hash_new = NULL
__futex_pivot_hash(mm, new)
rcu_assign_pointer(hash, new)
fph = rcu_dereference(hash) /* new */
futex_ref_is_dead(fph) -> false
schedule()CVSS
NVD no ha asignado puntuación CVSS a esta CVE (habitual desde el cambio de política de abril de 2026).
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.21%
- Percentil entre todas las CVEs puntuadas: 10
- Fecha de la puntuación: 5/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
Tecnologías afectadas (1)
⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.
Referencias
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-80776",
"cveTags": [],
"metrics": {},
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "bd54df5ea7cadac520e346d5f0fe5d58e635b6ba",
"lessThan": "4a7e941ca29a608c6244cbd028d3599ecaef7207",
"versionType": "git"
},
{
"status": "affected",
"version": "bd54df5ea7cadac520e346d5f0fe5d58e635b6ba",
"lessThan": "19b4be0717fa83265d66aea836b7022d898422cf",
"versionType": "git"
},
{
"status": "affected",
"version": "bd54df5ea7cadac520e346d5f0fe5d58e635b6ba",
"lessThan": "8e7ff730dd96519a333d1570edf1c3fabb6d3629",
"versionType": "git"
}
],
"programFiles": [
"kernel/futex/core.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.16"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.16",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.18.46",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.1.11",
"versionType": "semver",
"lessThanOrEqual": "7.1.*"
},
{
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"kernel/futex/core.c"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2026-09-04T16:18:03.250",
"references": [
{
"url": "https://git.kernel.org/stable/c/19b4be0717fa83265d66aea836b7022d898422cf",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/4a7e941ca29a608c6244cbd028d3599ecaef7207",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/8e7ff730dd96519a333d1570edf1c3fabb6d3629",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Received",
"descriptions": [
{
"lang": "en",
"value": "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) -> 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) -> 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."
}
],
"lastModified": "2026-09-04T16:18:03.250",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}