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CVE-2026-63884

Estado: Pendiente de análisisAlta (7.8)—

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

drm/i915: Fix potential UAF in TTM object purge

A user reported hitting the following bug under heavy use on DG2:

Results from decode_stacktrace.sh pointed to dereference of a file pointer field of a i915 TTM page vector container associated with an object being purged on eviction. That path is taken when the object is marked as no longer needed.

Code analysis revealed a possibility of the i915 TTM page vector container being replaced with a new instance inside a function that purges content of the object, should it be still busy. That function is called, indirectly via a more general function that changes the object's placement and caching policy, ---truncated---

Detalles técnicos trazas, registros y código del informe original
TLDR: The bo->ttm object might be changed by calling ttm_bo_validate(),
      move casting it to an i915_tt object later to actually get the right
      pointer.

[26620.095550] Oops: general protection fault, probably for non-canonical address 0xa56b6b6b6b6b6b8b: 0000 1 SMP NOPTI
[26620.095556] CPU: 2 UID: 0 PID: 631 Comm: Xorg Not tainted 6.18.8 #1 PREEMPT(lazy)
[26620.095558] Hardware name: ASRock B850M Steel Legend WiFi/B850M Steel Legend WiFi, BIOS 3.50 09/18/2025
[26620.095559] RIP: 0010:i915_ttm_purge+0x84/0x100 [i915]
[26620.095604] Code: 00 00 00 48 8d 54 24 10 48 89 e6 48 89 fb e8 83 aa ae ff 85 c0 75 6f 48 83 bb a8 01 00 00 00 74 2c 48 8b 45 78 48 85 c0 74 23 <48> 8b 78 20 48 c7 c2 ff ff ff ff 31 f6 e8 7a 73 e3 e0 48 8b 7d 78
[26620.095605] RSP: 0018:ffffc90005fd7430 EFLAGS: 00010282
[26620.095607] RAX: a56b6b6b6b6b6b6b RBX: ffff8881f46c3dc0 RCX: 0000000000000000
[26620.095608] RDX: 0000000000000000 RSI: 0000000000000246 RDI: 00000000ffffffff
[26620.095609] RBP: ffff888289610f00 R08: 0000000000000001 R09: ffff88823b022000
[26620.095609] R10: ffff888103029b28 R11: ffff8881fc7f3800 R12: ffff88810b6150d0
[26620.095609] R13: ffff888289610f00 R14: 0000000000000000 R15: ffff8881f46c3dc0
[26620.095610] FS: 00007f1004d86900(0000) GS:ffff88901c858000(0000) knlGS:0000000000000000
[26620.095611] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[26620.095611] CR2: 00007f0fdf489000 CR3: 000000035b0c1000 CR4: 0000000000750ef0
[26620.095612] PKRU: 55555554
[26620.095612] Call Trace:
[26620.095615] <TASK>
[26620.095615] i915_ttm_move+0x2b9/0x420 [i915]
[26620.095642] ? ttm_tt_init+0x65/0x80 [ttm]
[26620.095644] ? i915_ttm_tt_create+0xc6/0x150 [i915]
[26620.095667] ttm_bo_handle_move_mem+0xb6/0x160 [ttm]
[26620.095669] ttm_bo_evict+0x100/0x150 [ttm]
[26620.095671] ? preempt_count_add+0x64/0xa0
[26620.095673] ? _raw_spin_lock+0xe/0x30
[26620.095675] ? _raw_spin_unlock+0xd/0x30
[26620.095675] ? i915_gem_object_evictable+0xb7/0xd0 [i915]
[26620.095704] ttm_bo_evict_cb+0x6e/0xd0 [ttm]
[26620.095705] ttm_lru_walk_for_evict+0xa6/0x200 [ttm]
[26620.095708] ttm_bo_alloc_resource+0x185/0x4f0 [ttm]
[26620.095709] ? init_object+0x62/0xd0
[26620.095712] ttm_bo_validate+0x7a/0x180 [ttm]
[26620.095713] ? _raw_spin_unlock_irqrestore+0x16/0x30
[26620.095714] __i915_ttm_get_pages+0xb0/0x170 [i915]
[26620.095737] i915_ttm_get_pages+0x9f/0x150 [i915]
[26620.095759] ? i915_gem_do_execbuffer+0xedc/0x2b40 [i915]
[26620.095786] ? alloc_debug_processing+0xd0/0x100
[26620.095787] ? _raw_spin_unlock_irqrestore+0x16/0x30
[26620.095788] ? i915_vma_instance+0xa0/0x4e0 [i915]
[26620.095822] __i915_gem_object_get_pages+0x2f/0x40 [i915]
[26620.095848] i915_vma_pin_ww+0x706/0x980 [i915]
[26620.095875] ? i915_gem_do_execbuffer+0xedc/0x2b40 [i915]
[26620.095904] eb_validate_vmas+0x170/0xa00 [i915]
[26620.095930] i915_gem_do_execbuffer+0x1201/0x2b40 [i915]
[26620.095953] ? alloc_debug_processing+0xd0/0x100
[26620.095954] ? _raw_spin_unlock_irqrestore+0x16/0x30
[26620.095955] ? i915_gem_execbuffer2_ioctl+0xc9/0x240 [i915]
[26620.095977] ? __wake_up_sync_key+0x32/0x50
[26620.095979] ? i915_gem_execbuffer2_ioctl+0xc9/0x240 [i915]
[26620.096001] ? __slab_alloc.isra.0+0x67/0xc0
[26620.096003] i915_gem_execbuffer2_ioctl+0x11a/0x240 [i915]

CVSS

Probabilidad de explotación (EPSS)

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.

Vulnerabilidad local en kernel Linux (AV:L, PR:L) que causa Use-After-Free en gestión de memoria TTM. Atacante con acceso local puede provocar pánico del kernel (DoS) o corrupción de datos al desreferenciar punteros inválidos durante evicción de objetos.

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

JSON original (NVD)

Mostrar
{
  "id": "CVE-2026-63884",
  "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
      }
    ]
  },
  "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": "7ae034590ceaefd4d37465e3434877acfbadf411",
              "lessThan": "df73f3bc731af1c39ac5405bc59c4e7c6f8e9117",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "7ae034590ceaefd4d37465e3434877acfbadf411",
              "lessThan": "28b22dbaf407598cb3bb1d2c586a6f8018690ac2",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "7ae034590ceaefd4d37465e3434877acfbadf411",
              "lessThan": "073bcbc95e9648c976da1654c7590a8d6ee12c2d",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "7ae034590ceaefd4d37465e3434877acfbadf411",
              "lessThan": "c9ae7e7e3bc98615364313b08d7acea5239ded0b",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "7ae034590ceaefd4d37465e3434877acfbadf411",
              "lessThan": "a29654d451bbffe63d584a4cf64ad0efce6bcf1c",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "7ae034590ceaefd4d37465e3434877acfbadf411",
              "lessThan": "5c4063c87a619e4df954c179d24628636f5db15f",
              "versionType": "git"
            }
          ],
          "programFiles": [
            "drivers/gpu/drm/i915/gem/i915_gem_ttm.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.17"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "5.17",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "6.1.176",
              "versionType": "semver",
              "lessThanOrEqual": "6.1.*"
            },
            {
              "status": "unaffected",
              "version": "6.6.143",
              "versionType": "semver",
              "lessThanOrEqual": "6.6.*"
            },
            {
              "status": "unaffected",
              "version": "6.12.93",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "status": "unaffected",
              "version": "6.18.35",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "status": "unaffected",
              "version": "7.0.12",
              "versionType": "semver",
              "lessThanOrEqual": "7.0.*"
            },
            {
              "status": "unaffected",
              "version": "7.1",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "drivers/gpu/drm/i915/gem/i915_gem_ttm.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2026-07-19T16:17:05.463",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/073bcbc95e9648c976da1654c7590a8d6ee12c2d",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/28b22dbaf407598cb3bb1d2c586a6f8018690ac2",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/5c4063c87a619e4df954c179d24628636f5db15f",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/a29654d451bbffe63d584a4cf64ad0efce6bcf1c",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/c9ae7e7e3bc98615364313b08d7acea5239ded0b",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/df73f3bc731af1c39ac5405bc59c4e7c6f8e9117",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Awaiting Analysis",
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/i915: Fix potential UAF in TTM object purge\n\nTLDR: The bo->ttm object might be changed by calling ttm_bo_validate(),\n      move casting it to an i915_tt object later to actually get the right\n      pointer.\n\nA user reported hitting the following bug under heavy use on DG2:\n\n[26620.095550] Oops: general protection fault, probably for non-canonical address 0xa56b6b6b6b6b6b8b: 0000 1 SMP NOPTI\n[26620.095556] CPU: 2 UID: 0 PID: 631 Comm: Xorg Not tainted 6.18.8 #1 PREEMPT(lazy)\n[26620.095558] Hardware name: ASRock B850M Steel Legend WiFi/B850M Steel Legend WiFi, BIOS 3.50 09/18/2025\n[26620.095559] RIP: 0010:i915_ttm_purge+0x84/0x100 [i915]\n[26620.095604] Code: 00 00 00 48 8d 54 24 10 48 89 e6 48 89 fb e8 83 aa ae ff 85 c0 75 6f 48 83 bb a8 01 00 00 00 74 2c 48 8b 45 78 48 85 c0 74 23 <48> 8b 78 20 48 c7 c2 ff ff ff ff 31 f6 e8 7a 73 e3 e0 48 8b 7d 78\n[26620.095605] RSP: 0018:ffffc90005fd7430 EFLAGS: 00010282\n[26620.095607] RAX: a56b6b6b6b6b6b6b RBX: ffff8881f46c3dc0 RCX: 0000000000000000\n[26620.095608] RDX: 0000000000000000 RSI: 0000000000000246 RDI: 00000000ffffffff\n[26620.095609] RBP: ffff888289610f00 R08: 0000000000000001 R09: ffff88823b022000\n[26620.095609] R10: ffff888103029b28 R11: ffff8881fc7f3800 R12: ffff88810b6150d0\n[26620.095609] R13: ffff888289610f00 R14: 0000000000000000 R15: ffff8881f46c3dc0\n[26620.095610] FS: 00007f1004d86900(0000) GS:ffff88901c858000(0000) knlGS:0000000000000000\n[26620.095611] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n[26620.095611] CR2: 00007f0fdf489000 CR3: 000000035b0c1000 CR4: 0000000000750ef0\n[26620.095612] PKRU: 55555554\n[26620.095612] Call Trace:\n[26620.095615] <TASK>\n[26620.095615] i915_ttm_move+0x2b9/0x420 [i915]\n[26620.095642] ? ttm_tt_init+0x65/0x80 [ttm]\n[26620.095644] ? i915_ttm_tt_create+0xc6/0x150 [i915]\n[26620.095667] ttm_bo_handle_move_mem+0xb6/0x160 [ttm]\n[26620.095669] ttm_bo_evict+0x100/0x150 [ttm]\n[26620.095671] ? preempt_count_add+0x64/0xa0\n[26620.095673] ? _raw_spin_lock+0xe/0x30\n[26620.095675] ? _raw_spin_unlock+0xd/0x30\n[26620.095675] ? i915_gem_object_evictable+0xb7/0xd0 [i915]\n[26620.095704] ttm_bo_evict_cb+0x6e/0xd0 [ttm]\n[26620.095705] ttm_lru_walk_for_evict+0xa6/0x200 [ttm]\n[26620.095708] ttm_bo_alloc_resource+0x185/0x4f0 [ttm]\n[26620.095709] ? init_object+0x62/0xd0\n[26620.095712] ttm_bo_validate+0x7a/0x180 [ttm]\n[26620.095713] ? _raw_spin_unlock_irqrestore+0x16/0x30\n[26620.095714] __i915_ttm_get_pages+0xb0/0x170 [i915]\n[26620.095737] i915_ttm_get_pages+0x9f/0x150 [i915]\n[26620.095759] ? i915_gem_do_execbuffer+0xedc/0x2b40 [i915]\n[26620.095786] ? alloc_debug_processing+0xd0/0x100\n[26620.095787] ? _raw_spin_unlock_irqrestore+0x16/0x30\n[26620.095788] ? i915_vma_instance+0xa0/0x4e0 [i915]\n[26620.095822] __i915_gem_object_get_pages+0x2f/0x40 [i915]\n[26620.095848] i915_vma_pin_ww+0x706/0x980 [i915]\n[26620.095875] ? i915_gem_do_execbuffer+0xedc/0x2b40 [i915]\n[26620.095904] eb_validate_vmas+0x170/0xa00 [i915]\n[26620.095930] i915_gem_do_execbuffer+0x1201/0x2b40 [i915]\n[26620.095953] ? alloc_debug_processing+0xd0/0x100\n[26620.095954] ? _raw_spin_unlock_irqrestore+0x16/0x30\n[26620.095955] ? i915_gem_execbuffer2_ioctl+0xc9/0x240 [i915]\n[26620.095977] ? __wake_up_sync_key+0x32/0x50\n[26620.095979] ? i915_gem_execbuffer2_ioctl+0xc9/0x240 [i915]\n[26620.096001] ? __slab_alloc.isra.0+0x67/0xc0\n[26620.096003] i915_gem_execbuffer2_ioctl+0x11a/0x240 [i915]\n\nResults from decode_stacktrace.sh pointed to dereference of a file pointer\nfield of a i915 TTM page vector container associated with an object being\npurged on eviction.  That path is taken when the object is marked as no\nlonger needed.\n\nCode analysis revealed a possibility of the i915 TTM page vector container\nbeing replaced with a new instance inside a function that purges content\nof the object, should it be still busy.  That function is called,\nindirectly via a more general function that changes the object's placement\nand caching policy,\n---truncated---"
    }
  ],
  "lastModified": "2026-07-27T17:44:23.777",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}