CVE-2026-93182
Estado: RecibidaSin puntuar—
In the Linux kernel, the following vulnerability has been resolved:
sched/fair: Fix overflow in update_tg_cfs_runnable()
A divide-by-zero crash is observed when running hackbench:
The divide-by-zero happens here:
gcfs_rq->load.weight is an insane large value and is truncated to the lower 32 bits by div_u64, which happen to be 0.
Using AI for investigation, the cause is a u32 overflow in update_tg_cfs_runnable(), and flat pickup became a victim when using tg_tasks():
The following sequence shows how this triggers the crash:
Fix by widening new_sum from u32 to u64 (no need to force tg_tasks() to return unsigned long after this fix)
Detalles técnicos trazas, registros y código del informe original
[14697.488452] CPU: 112 UID: 0 PID: 124791 Comm: hackbench Not tainted 7.1.0-rc2+
[14697.492627] RIP: 0010:propagate_entity_load_avg+0x35f/0x3e0
[14697.506799] <TASK>
[14697.507411] __dequeue_task+0x2b4/0xc70
[14697.508677] dequeue_task_fair+0x36/0x370
[14697.509047] dequeue_task+0x101/0x2f0
[14697.509426] __schedule+0x1b1/0x1a00
[14697.510868] anon_pipe_read+0x3da/0x450
[14697.511400] vfs_read+0x361/0x390
[14697.512053] __x64_sys_read+0x19/0x30
if (scale_load_down(gcfs_rq->load.weight)) {
load_sum = div_u64(gcfs_rq->avg.load_sum,
scale_load_down(gcfs_rq->load.weight));
}
u32 new_sum, divider;
...
new_sum = se->avg.runnable_avg * divider; <-- boom
propagate_entity_load_avg()
update_tg_cfs_runnable() # u32 overflow corrupts runnable_sum
__update_load_avg_cfs_rq()
___update_load_avg() # computes insane runnable_avg
update_tg_load_avg() # propagates to tg->runnable_avg
update_cfs_group()
calc_concur_shares()
tg_tasks() # long-to-int truncation, negative nr
reweight_entity() # corrupted se->load.weight
update_load_add() # corrupted cfs_rq->load.weight
propagate_entity_load_avg()
update_tg_cfs_load()
div_u64() # divide-by-zeroCVSS
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: 11
- Fecha de la puntuación: 6/10/2026
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
- https://git.kernel.org/stable/c/18fdd0978ec3dda0ff6865cd273e47e022180710
- https://git.kernel.org/stable/c/39d707097a0820c6e87eff4195f0940e8ff1147e
- https://git.kernel.org/stable/c/4f166adb5cb0525d9e32d45729fd8f28c80acbee
- https://git.kernel.org/stable/c/69fafae4eb2c9fc9bcff1bcbfcccf5d197434d75
- https://git.kernel.org/stable/c/7cc237e3bc1733928313d2462b413ae441b0eef3
- https://git.kernel.org/stable/c/f94e62d21faad5e244d0874598a4d0ebbc0ea405
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-93182",
"cveTags": [],
"metrics": {},
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
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{
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],
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},
{
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{
"status": "affected",
"version": "5.17"
},
{
"status": "unaffected",
"version": "0",
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"versionType": "semver"
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{
"status": "unaffected",
"version": "6.1.188",
"versionType": "semver",
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},
{
"status": "unaffected",
"version": "6.6.157",
"versionType": "semver",
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},
{
"status": "unaffected",
"version": "6.12.110",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.52",
"versionType": "semver",
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},
{
"status": "unaffected",
"version": "7.2.6",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
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"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
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],
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}
]
}
],
"published": "2026-09-17T17:18:14.153",
"references": [
{
"url": "https://git.kernel.org/stable/c/18fdd0978ec3dda0ff6865cd273e47e022180710",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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{
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"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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{
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"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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{
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"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
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{
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"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Received",
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsched/fair: Fix overflow in update_tg_cfs_runnable()\n\nA divide-by-zero crash is observed when running hackbench:\n\n [14697.488452] CPU: 112 UID: 0 PID: 124791 Comm: hackbench Not tainted 7.1.0-rc2+\n [14697.492627] RIP: 0010:propagate_entity_load_avg+0x35f/0x3e0\n [14697.506799] <TASK>\n [14697.507411] __dequeue_task+0x2b4/0xc70\n [14697.508677] dequeue_task_fair+0x36/0x370\n [14697.509047] dequeue_task+0x101/0x2f0\n [14697.509426] __schedule+0x1b1/0x1a00\n [14697.510868] anon_pipe_read+0x3da/0x450\n [14697.511400] vfs_read+0x361/0x390\n [14697.512053] __x64_sys_read+0x19/0x30\n\nThe divide-by-zero happens here:\n\n if (scale_load_down(gcfs_rq->load.weight)) {\n load_sum = div_u64(gcfs_rq->avg.load_sum,\n scale_load_down(gcfs_rq->load.weight));\n }\n\ngcfs_rq->load.weight is an insane large value and is truncated\nto the lower 32 bits by div_u64, which happen to be 0.\n\nUsing AI for investigation, the cause is a u32 overflow in\nupdate_tg_cfs_runnable(), and flat pickup became a victim when using\ntg_tasks():\n\n u32 new_sum, divider;\n ...\n new_sum = se->avg.runnable_avg * divider; <-- boom\n\nThe following sequence shows how this triggers the crash:\n\n propagate_entity_load_avg()\n update_tg_cfs_runnable() # u32 overflow corrupts runnable_sum\n\n __update_load_avg_cfs_rq()\n ___update_load_avg() # computes insane runnable_avg\n update_tg_load_avg() # propagates to tg->runnable_avg\n\n update_cfs_group()\n calc_concur_shares()\n tg_tasks() # long-to-int truncation, negative nr\n reweight_entity() # corrupted se->load.weight\n update_load_add() # corrupted cfs_rq->load.weight\n\n propagate_entity_load_avg()\n update_tg_cfs_load()\n div_u64() # divide-by-zero\n\nFix by widening new_sum from u32 to u64 (no need to force tg_tasks()\nto return unsigned long after this fix)"
}
],
"lastModified": "2026-09-17T17:18:14.153",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}