CVE-2026-89856
In the Linux kernel, the following vulnerability has been resolved:
scsi: qla2xxx: Clamp MSI-X derived queue counts to avoid truncation
ha->msix_count is u16, but ha->max_req_queues, ha->max_rsp_queues and ha->max_qpairs are u8. Deriving the queue count as "ha->max_req_queues = ha->msix_count - 1" therefore truncates: a board (or a misconfigured/malicious hot-plugged device) advertising 257 MSI-X vectors yields msix_count - 1 == 256, which truncates to 0. An MSI-X count of 1 zeroes it as well, and in target mode the subsequent "ha->max_req_queues--" then underflows 0 to 255.
When the count is 0, qla2x00_alloc_queues() calls kzalloc_objs(struct req_que *, 0), which returns ZERO_SIZE_PTR.
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That is not NULL, so the allocation check passes and the following "ha->req_q_map[0] = req" dereferences ZERO_SIZE_PTR, corrupting memory or crashing the kernel.
Add qla_calc_queue_count() to clamp the derived value into [1, QLA_MAX_QUEUES - 1] so it always fits in u8 and is never zero, and use it at all three derivation sites (qla25xx_iospace_config(), qla83xx_iospace_config() and qla24xx_enable_msix()). Also guard the target-mode decrement so it cannot reintroduce a zero (which would in turn underflow max_qpairs).
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Puntuación base: 8.4
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.20%
- Percentil entre todas las CVEs puntuadas: 8
- 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).
🎯 Técnicas ATT&CK
Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.
- Explotación
T1068Exploitation for Privilege Escalationprivilege escalation75 % - Impacto principal
T1499.004Application or System Exploitationimpact60 % - Impacto secundario
T1565.001Stored Data Manipulationimpact55 %
Vulnerabilidad local de truncamiento en qla2xxx sin requerir privilegios (PR:N) que causa corrupción de memoria (C:H,I:H,A:H) o crash del kernel; escalada típica por malformación de dispositivo/syscall local.
Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.
🛡️ Mitigaciones ATT&CK que cubren estas técnicas
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/2efe50b2da829909023de4a2eb87badb7cfa53cc
- https://git.kernel.org/stable/c/33c77254e6e91f37c72c7fad4051777452b10de8
- https://git.kernel.org/stable/c/7a448f5ed0b283dbde4e9183dd1e98c221432dab
- https://git.kernel.org/stable/c/802068b9b683b8008fcccbf6e9ad133e597ec87c
- https://git.kernel.org/stable/c/9eeddbeaa896f39d943644b16d83a6ad0ceab255
- https://git.kernel.org/stable/c/cf623d32761b00f221a9cfded3303d56e84b429d
- https://git.kernel.org/stable/c/e80adfeac61b4d5db7ffe0f5af43999c33a4145e
- https://git.kernel.org/stable/c/ebfd35c64433821bd5619a6d07ccc2df8b5b1de3
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-89856",
"cveTags": [],
"metrics": {
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{
"type": "Secondary",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 8.4,
"attackVector": "LOCAL",
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"integrityImpact": "HIGH",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "HIGH",
"privilegesRequired": "NONE",
"confidentialityImpact": "HIGH"
},
"impactScore": 5.9,
"exploitabilityScore": 2.5
}
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"affectedData": [
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"drivers/scsi/qla2xxx/qla_isr.c",
"drivers/scsi/qla2xxx/qla_os.c"
],
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{
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],
"defaultStatus": "affected"
}
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}
],
"published": "2026-09-16T11:16:53.440",
"references": [
{
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}
],
"vulnStatus": "Received",
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nscsi: qla2xxx: Clamp MSI-X derived queue counts to avoid truncation\n\nha->msix_count is u16, but ha->max_req_queues, ha->max_rsp_queues and\nha->max_qpairs are u8. Deriving the queue count as\n\"ha->max_req_queues = ha->msix_count - 1\" therefore truncates: a board\n(or a misconfigured/malicious hot-plugged device) advertising 257 MSI-X\nvectors yields msix_count - 1 == 256, which truncates to 0. An MSI-X\ncount of 1 zeroes it as well, and in target mode the subsequent\n\"ha->max_req_queues--\" then underflows 0 to 255.\n\nWhen the count is 0, qla2x00_alloc_queues() calls\nkzalloc_objs(struct req_que *, 0), which returns ZERO_SIZE_PTR. That is\nnot NULL, so the allocation check passes and the following\n\"ha->req_q_map[0] = req\" dereferences ZERO_SIZE_PTR, corrupting memory\nor crashing the kernel.\n\nAdd qla_calc_queue_count() to clamp the derived value into\n[1, QLA_MAX_QUEUES - 1] so it always fits in u8 and is never zero, and\nuse it at all three derivation sites (qla25xx_iospace_config(),\nqla83xx_iospace_config() and qla24xx_enable_msix()). Also guard the\ntarget-mode decrement so it cannot reintroduce a zero (which would in\nturn underflow max_qpairs)."
}
],
"lastModified": "2026-09-16T15:18:13.507",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}