CVE-2025-39945
Estado: ModificadaAlta (7.8)—
In the Linux kernel, the following vulnerability has been resolved:
cnic: Fix use-after-free bugs in cnic_delete_task
The original code uses cancel_delayed_work() in cnic_cm_stop_bnx2x_hw(), which does not guarantee that the delayed work item 'delete_task' has fully completed if it was already running. Additionally, the delayed work item is cyclic, the flush_workqueue() in cnic_cm_stop_bnx2x_hw() only blocks and waits for work items that were already queued to the workqueue prior to its invocation.
Leer descripción completaMostrar menos
Any work items submitted after flush_workqueue() is called are not included in the set of tasks that the flush operation awaits. This means that after the cyclic work items have finished executing, a delayed work item may still exist in the workqueue. This leads to use-after-free scenarios where the cnic_dev is deallocated by cnic_free_dev(), while delete_task remains active and attempt to dereference cnic_dev in cnic_delete_task().
A typical race condition is illustrated below:
Replace cancel_delayed_work() with cancel_delayed_work_sync() to ensure that the cyclic delayed work item is properly canceled and that any ongoing execution of the work item completes before the cnic_dev is deallocated. Furthermore, since cancel_delayed_work_sync() uses __flush_work(work, true) to synchronously wait for any currently executing instance of the work item to finish, the flush_workqueue() becomes redundant and should be removed.
This bug was identified through static analysis. To reproduce the issue and validate the fix, I simulated the cnic PCI device in QEMU and introduced intentional delays — such as inserting calls to ssleep() within the cnic_delete_task() function — to increase the likelihood of triggering the bug.
Detalles técnicos trazas, registros y código del informe original
CPU 0 (cleanup) | CPU 1 (delayed work callback)
cnic_netdev_event() |
cnic_stop_hw() | cnic_delete_task()
cnic_cm_stop_bnx2x_hw() | ...
cancel_delayed_work() | /* the queue_delayed_work()
flush_workqueue() | executes after flush_workqueue()*/
| queue_delayed_work()
cnic_free_dev(dev)//free | cnic_delete_task() //new instance
| dev = cp->dev; //useCVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Puntuación base: 7.8
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.16%
- Percentil entre todas las CVEs puntuadas: 4
- 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
T1059Command and Scripting Interpreterexecution60 %
Vulnerabilidad de use-after-free (CWE-416) con vector AV:L/PR:L en kernel Linux. La escalada de privilegios local mediante race condition en cnic_delete_task permite ejecución de código con contexto de kernel. Requiere acceso local con permisos limitados.
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)
CWE
- CWE-416
Referencias
- https://git.kernel.org/stable/c/0405055930264ea8fd26f4131466fa7652e5e47d
- https://git.kernel.org/stable/c/0627e1481676669cae2df0d85b5ff13e7d24c390
- https://git.kernel.org/stable/c/6e33a7eed587062ca8161ad1f4584882a860d697
- https://git.kernel.org/stable/c/7b6a5b0a6b392263c3767fc945b311ea04b34bbd
- https://git.kernel.org/stable/c/8eeb2091e72d75df8ceaa2172638d61b4cf8929a
- https://git.kernel.org/stable/c/cfa7d9b1e3a8604afc84e9e51d789c29574fb216
- https://git.kernel.org/stable/c/e1fcd4a9c09feac0902a65615e866dbf22616125
- https://git.kernel.org/stable/c/fde6e73189f40ebcf0633aed2b68e731c25f3aa3
JSON original (NVD)
Mostrar
{
"id": "CVE-2025-39945",
"cveTags": [],
"metrics": {
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2025-39945",
"role": "CISA Coordinator",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "total"
}
],
"version": "2.0.3",
"timestamp": "2026-06-10T20:41:21.785248Z"
}
}
],
"cvssMetricV31": [
{
"type": "Secondary",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 7.8,
"attackVector": "LOCAL",
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"integrityImpact": "HIGH",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "HIGH",
"privilegesRequired": "LOW",
"confidentialityImpact": "HIGH"
},
"impactScore": 5.9,
"exploitabilityScore": 1.8
},
{
"type": "Primary",
"source": "nvd@nist.gov",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 7.8,
"attackVector": "LOCAL",
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"integrityImpact": "HIGH",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "HIGH",
"privilegesRequired": "LOW",
"confidentialityImpact": "HIGH"
},
"impactScore": 5.9,
"exploitabilityScore": 1.8
}
]
},
"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": "fdf24086f4752aee5dfb40143c736250df017820",
"lessThan": "fde6e73189f40ebcf0633aed2b68e731c25f3aa3",
"versionType": "git"
},
{
"status": "affected",
"version": "fdf24086f4752aee5dfb40143c736250df017820",
"lessThan": "7b6a5b0a6b392263c3767fc945b311ea04b34bbd",
"versionType": "git"
},
{
"status": "affected",
"version": "fdf24086f4752aee5dfb40143c736250df017820",
"lessThan": "0405055930264ea8fd26f4131466fa7652e5e47d",
"versionType": "git"
},
{
"status": "affected",
"version": "fdf24086f4752aee5dfb40143c736250df017820",
"lessThan": "e1fcd4a9c09feac0902a65615e866dbf22616125",
"versionType": "git"
},
{
"status": "affected",
"version": "fdf24086f4752aee5dfb40143c736250df017820",
"lessThan": "8eeb2091e72d75df8ceaa2172638d61b4cf8929a",
"versionType": "git"
},
{
"status": "affected",
"version": "fdf24086f4752aee5dfb40143c736250df017820",
"lessThan": "6e33a7eed587062ca8161ad1f4584882a860d697",
"versionType": "git"
},
{
"status": "affected",
"version": "fdf24086f4752aee5dfb40143c736250df017820",
"lessThan": "0627e1481676669cae2df0d85b5ff13e7d24c390",
"versionType": "git"
},
{
"status": "affected",
"version": "fdf24086f4752aee5dfb40143c736250df017820",
"lessThan": "cfa7d9b1e3a8604afc84e9e51d789c29574fb216",
"versionType": "git"
}
],
"programFiles": [
"drivers/net/ethernet/broadcom/cnic.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "2.6.37"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "2.6.37",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.4.300",
"versionType": "semver",
"lessThanOrEqual": "5.4.*"
},
{
"status": "unaffected",
"version": "5.10.245",
"versionType": "semver",
"lessThanOrEqual": "5.10.*"
},
{
"status": "unaffected",
"version": "5.15.194",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.154",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.108",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.49",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.16.9",
"versionType": "semver",
"lessThanOrEqual": "6.16.*"
},
{
"status": "unaffected",
"version": "6.17",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"drivers/net/ethernet/broadcom/cnic.c"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2025-10-04T08:15:47.613",
"references": [
{
"url": "https://git.kernel.org/stable/c/0405055930264ea8fd26f4131466fa7652e5e47d",
"tags": [
"Patch"
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/0627e1481676669cae2df0d85b5ff13e7d24c390",
"tags": [
"Patch"
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/6e33a7eed587062ca8161ad1f4584882a860d697",
"tags": [
"Patch"
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/7b6a5b0a6b392263c3767fc945b311ea04b34bbd",
"tags": [
"Patch"
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/8eeb2091e72d75df8ceaa2172638d61b4cf8929a",
"tags": [
"Patch"
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/cfa7d9b1e3a8604afc84e9e51d789c29574fb216",
"tags": [
"Patch"
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/e1fcd4a9c09feac0902a65615e866dbf22616125",
"tags": [
"Patch"
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/fde6e73189f40ebcf0633aed2b68e731c25f3aa3",
"tags": [
"Patch"
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Modified",
"weaknesses": [
{
"type": "Primary",
"source": "nvd@nist.gov",
"description": [
{
"lang": "en",
"value": "CWE-416"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncnic: Fix use-after-free bugs in cnic_delete_task\n\nThe original code uses cancel_delayed_work() in cnic_cm_stop_bnx2x_hw(),\nwhich does not guarantee that the delayed work item 'delete_task' has\nfully completed if it was already running. Additionally, the delayed work\nitem is cyclic, the flush_workqueue() in cnic_cm_stop_bnx2x_hw() only\nblocks and waits for work items that were already queued to the\nworkqueue prior to its invocation. Any work items submitted after\nflush_workqueue() is called are not included in the set of tasks that the\nflush operation awaits. This means that after the cyclic work items have\nfinished executing, a delayed work item may still exist in the workqueue.\nThis leads to use-after-free scenarios where the cnic_dev is deallocated\nby cnic_free_dev(), while delete_task remains active and attempt to\ndereference cnic_dev in cnic_delete_task().\n\nA typical race condition is illustrated below:\n\nCPU 0 (cleanup) | CPU 1 (delayed work callback)\ncnic_netdev_event() |\n cnic_stop_hw() | cnic_delete_task()\n cnic_cm_stop_bnx2x_hw() | ...\n cancel_delayed_work() | /* the queue_delayed_work()\n flush_workqueue() | executes after flush_workqueue()*/\n | queue_delayed_work()\n cnic_free_dev(dev)//free | cnic_delete_task() //new instance\n | dev = cp->dev; //use\n\nReplace cancel_delayed_work() with cancel_delayed_work_sync() to ensure\nthat the cyclic delayed work item is properly canceled and that any\nongoing execution of the work item completes before the cnic_dev is\ndeallocated. Furthermore, since cancel_delayed_work_sync() uses\n__flush_work(work, true) to synchronously wait for any currently\nexecuting instance of the work item to finish, the flush_workqueue()\nbecomes redundant and should be removed.\n\nThis bug was identified through static analysis. To reproduce the issue\nand validate the fix, I simulated the cnic PCI device in QEMU and\nintroduced intentional delays — such as inserting calls to ssleep()\nwithin the cnic_delete_task() function — to increase the likelihood\nof triggering the bug."
}
],
"lastModified": "2026-07-30T06:23:59.567",
"configurations": [
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "7175A0F5-9125-4D84-A39A-3FA75A464894",
"versionEndExcluding": "5.4.300",
"versionStartIncluding": "2.6.37"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "B0E443AF-02FC-45A1-9CD7-3F80A65F1A15",
"versionEndExcluding": "5.10.245",
"versionStartIncluding": "5.5"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "CF862263-DC8D-4324-A52A-DA1D7880B35A",
"versionEndExcluding": "5.15.194",
"versionStartIncluding": "5.11"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "E49CD91E-FC55-45B0-BB63-9AD5F5D70CAA",
"versionEndExcluding": "6.1.154",
"versionStartIncluding": "5.16"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "A7E8EAEE-7731-4996-9578-696255D61EA2",
"versionEndExcluding": "6.6.108",
"versionStartIncluding": "6.2"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "CAA033E9-A2C5-4976-A83E-9804D8FB827F",
"versionEndExcluding": "6.12.49",
"versionStartIncluding": "6.7"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "638DD910-1189-4F5E-98BF-2D436B695112",
"versionEndExcluding": "6.16.9",
"versionStartIncluding": "6.13"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:6.17:rc1:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "327D22EF-390B-454C-BD31-2ED23C998A1C"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:6.17:rc2:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "C730CD9A-D969-4A8E-9522-162AAF7C0EE9"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:6.17:rc3:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "39982C4B-716E-4B2F-8196-FA301F47807D"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:6.17:rc4:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "340BEEA9-D70D-4290-B502-FBB1032353B1"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:6.17:rc5:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "47E4C5C0-079F-4838-971B-8C503D48FCC2"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:6.17:rc6:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "5A4516A6-C12E-42A4-8C0E-68AEF3264504"
}
],
"operator": "OR"
}
]
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}