CVE-2025-39944

Estado: ModificadaAlta (7.8)—

In the Linux kernel, the following vulnerability has been resolved:

octeontx2-pf: Fix use-after-free bugs in otx2_sync_tstamp()

The original code relies on cancel_delayed_work() in otx2_ptp_destroy(), which does not ensure that the delayed work item synctstamp_work has fully completed if it was already running. This leads to use-after-free scenarios where otx2_ptp is deallocated by otx2_ptp_destroy(), while synctstamp_work remains active and attempts to dereference otx2_ptp in otx2_sync_tstamp(). Furthermore, the synctstamp_work is cyclic, the likelihood of triggering the bug is nonnegligible.

A typical race condition is illustrated below:

Leer descripción completaMostrar menos

This is confirmed by a KASAN report:

Replace cancel_delayed_work() with cancel_delayed_work_sync() to ensure that the delayed work item is properly canceled before the otx2_ptp is deallocated.

This bug was initially identified through static analysis. To reproduce and test it, I simulated the OcteonTX2 PCI device in QEMU and introduced artificial delays within the otx2_sync_tstamp() 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)
otx2_remove()             |
  otx2_ptp_destroy()      | otx2_sync_tstamp()
    cancel_delayed_work() |
    kfree(ptp)            |
                          |   ptp = container_of(...); //UAF
                          |   ptp-> //UAF

BUG: KASAN: slab-use-after-free in __run_timer_base.part.0+0x7d7/0x8c0
Write of size 8 at addr ffff88800aa09a18 by task bash/136
...
Call Trace:
 <IRQ>
 dump_stack_lvl+0x55/0x70
 print_report+0xcf/0x610
 ? __run_timer_base.part.0+0x7d7/0x8c0
 kasan_report+0xb8/0xf0
 ? __run_timer_base.part.0+0x7d7/0x8c0
 __run_timer_base.part.0+0x7d7/0x8c0
 ? __pfx___run_timer_base.part.0+0x10/0x10
 ? __pfx_read_tsc+0x10/0x10
 ? ktime_get+0x60/0x140
 ? lapic_next_event+0x11/0x20
 ? clockevents_program_event+0x1d4/0x2a0
 run_timer_softirq+0xd1/0x190
 handle_softirqs+0x16a/0x550
 irq_exit_rcu+0xaf/0xe0
 sysvec_apic_timer_interrupt+0x70/0x80
 </IRQ>
...
Allocated by task 1:
 kasan_save_stack+0x24/0x50
 kasan_save_track+0x14/0x30
 __kasan_kmalloc+0x7f/0x90
 otx2_ptp_init+0xb1/0x860
 otx2_probe+0x4eb/0xc30
 local_pci_probe+0xdc/0x190
 pci_device_probe+0x2fe/0x470
 really_probe+0x1ca/0x5c0
 __driver_probe_device+0x248/0x310
 driver_probe_device+0x44/0x120
 __driver_attach+0xd2/0x310
 bus_for_each_dev+0xed/0x170
 bus_add_driver+0x208/0x500
 driver_register+0x132/0x460
 do_one_initcall+0x89/0x300
 kernel_init_freeable+0x40d/0x720
 kernel_init+0x1a/0x150
 ret_from_fork+0x10c/0x1a0
 ret_from_fork_asm+0x1a/0x30

Freed by task 136:
 kasan_save_stack+0x24/0x50
 kasan_save_track+0x14/0x30
 kasan_save_free_info+0x3a/0x60
 __kasan_slab_free+0x3f/0x50
 kfree+0x137/0x370
 otx2_ptp_destroy+0x38/0x80
 otx2_remove+0x10d/0x4c0
 pci_device_remove+0xa6/0x1d0
 device_release_driver_internal+0xf8/0x210
 pci_stop_bus_device+0x105/0x150
 pci_stop_and_remove_bus_device_locked+0x15/0x30
 remove_store+0xcc/0xe0
 kernfs_fop_write_iter+0x2c3/0x440
 vfs_write+0x871/0xd70
 ksys_write+0xee/0x1c0
 do_syscall_64+0xac/0x280
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
...

CVSS

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: 0.15%
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.

ExplotaciónT1068 Exploitation for Privilege Escalationprivilege escalation85 %
Impacto principalT1059 Command and Scripting Interpreterexecution75 %

Vulnerabilidad local (AV:L/PR:L) de use-after-free (CWE-416) en kernel Linux que permite ejecución de código arbitrario con privilegios elevados mediante condición de carrera en otx2_sync_tstamp().

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

Execution Prevention Threat Intelligence Program Restrict Web-Based Content Privileged Account Management Limit Software Installation Behavior Prevention on Endpoint

Tecnologías afectadas (1)

Linux — Linux Kernel

CWE

CWE-416

Referencias

JSON original (NVD)

Mostrar

{
  "id": "CVE-2025-39944",
  "cveTags": [],
  "metrics": {
    "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": "2958d17a898416c6193431676f6130b68a2cb9fc",
              "lessThan": "2786879aebf363806a13d41e8d5f99202ddd23d9",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "2958d17a898416c6193431676f6130b68a2cb9fc",
              "lessThan": "d2cfefa14ce8137b17f99683f968bebf134b6a48",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "2958d17a898416c6193431676f6130b68a2cb9fc",
              "lessThan": "ff27e23b311fed4d25e3852e27ba693416d4c7b3",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "2958d17a898416c6193431676f6130b68a2cb9fc",
              "lessThan": "5ca20bb7b4bde72110c3ae78423cbfdd0157aa36",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "2958d17a898416c6193431676f6130b68a2cb9fc",
              "lessThan": "f8b4687151021db61841af983f1cb7be6915d4ef",
              "versionType": "git"
            }
          ],
          "programFiles": [
            "drivers/net/ethernet/marvell/octeontx2/nic/otx2_ptp.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.1"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "6.1",
              "versionType": "semver"
            },
            {
              "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/marvell/octeontx2/nic/otx2_ptp.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2025-10-04T08:15:47.480",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/2786879aebf363806a13d41e8d5f99202ddd23d9",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/5ca20bb7b4bde72110c3ae78423cbfdd0157aa36",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/d2cfefa14ce8137b17f99683f968bebf134b6a48",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/f8b4687151021db61841af983f1cb7be6915d4ef",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/ff27e23b311fed4d25e3852e27ba693416d4c7b3",
      "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\nocteontx2-pf: Fix use-after-free bugs in otx2_sync_tstamp()\n\nThe original code relies on cancel_delayed_work() in otx2_ptp_destroy(),\nwhich does not ensure that the delayed work item synctstamp_work has fully\ncompleted if it was already running. This leads to use-after-free scenarios\nwhere otx2_ptp is deallocated by otx2_ptp_destroy(), while synctstamp_work\nremains active and attempts to dereference otx2_ptp in otx2_sync_tstamp().\nFurthermore, the synctstamp_work is cyclic, the likelihood of triggering\nthe bug is nonnegligible.\n\nA typical race condition is illustrated below:\n\nCPU 0 (cleanup)           | CPU 1 (delayed work callback)\notx2_remove()             |\n  otx2_ptp_destroy()      | otx2_sync_tstamp()\n    cancel_delayed_work() |\n    kfree(ptp)            |\n                          |   ptp = container_of(...); //UAF\n                          |   ptp-> //UAF\n\nThis is confirmed by a KASAN report:\n\nBUG: KASAN: slab-use-after-free in __run_timer_base.part.0+0x7d7/0x8c0\nWrite of size 8 at addr ffff88800aa09a18 by task bash/136\n...\nCall Trace:\n <IRQ>\n dump_stack_lvl+0x55/0x70\n print_report+0xcf/0x610\n ? __run_timer_base.part.0+0x7d7/0x8c0\n kasan_report+0xb8/0xf0\n ? __run_timer_base.part.0+0x7d7/0x8c0\n __run_timer_base.part.0+0x7d7/0x8c0\n ? __pfx___run_timer_base.part.0+0x10/0x10\n ? __pfx_read_tsc+0x10/0x10\n ? ktime_get+0x60/0x140\n ? lapic_next_event+0x11/0x20\n ? clockevents_program_event+0x1d4/0x2a0\n run_timer_softirq+0xd1/0x190\n handle_softirqs+0x16a/0x550\n irq_exit_rcu+0xaf/0xe0\n sysvec_apic_timer_interrupt+0x70/0x80\n </IRQ>\n...\nAllocated by task 1:\n kasan_save_stack+0x24/0x50\n kasan_save_track+0x14/0x30\n __kasan_kmalloc+0x7f/0x90\n otx2_ptp_init+0xb1/0x860\n otx2_probe+0x4eb/0xc30\n local_pci_probe+0xdc/0x190\n pci_device_probe+0x2fe/0x470\n really_probe+0x1ca/0x5c0\n __driver_probe_device+0x248/0x310\n driver_probe_device+0x44/0x120\n __driver_attach+0xd2/0x310\n bus_for_each_dev+0xed/0x170\n bus_add_driver+0x208/0x500\n driver_register+0x132/0x460\n do_one_initcall+0x89/0x300\n kernel_init_freeable+0x40d/0x720\n kernel_init+0x1a/0x150\n ret_from_fork+0x10c/0x1a0\n ret_from_fork_asm+0x1a/0x30\n\nFreed by task 136:\n kasan_save_stack+0x24/0x50\n kasan_save_track+0x14/0x30\n kasan_save_free_info+0x3a/0x60\n __kasan_slab_free+0x3f/0x50\n kfree+0x137/0x370\n otx2_ptp_destroy+0x38/0x80\n otx2_remove+0x10d/0x4c0\n pci_device_remove+0xa6/0x1d0\n device_release_driver_internal+0xf8/0x210\n pci_stop_bus_device+0x105/0x150\n pci_stop_and_remove_bus_device_locked+0x15/0x30\n remove_store+0xcc/0xe0\n kernfs_fop_write_iter+0x2c3/0x440\n vfs_write+0x871/0xd70\n ksys_write+0xee/0x1c0\n do_syscall_64+0xac/0x280\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n...\n\nReplace cancel_delayed_work() with cancel_delayed_work_sync() to ensure\nthat the delayed work item is properly canceled before the otx2_ptp is\ndeallocated.\n\nThis bug was initially identified through static analysis. To reproduce\nand test it, I simulated the OcteonTX2 PCI device in QEMU and introduced\nartificial delays within the otx2_sync_tstamp() function to increase the\nlikelihood of triggering the bug."
    }
  ],
  "lastModified": "2026-07-30T06:23:59.413",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "A57D06D5-F248-4BF0-8580-9873AB71028A",
              "versionEndExcluding": "6.1.154",
              "versionStartIncluding": "6.1"
            },
            {
              "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"
}