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CVE-2023-53846

Estado: AplazadaAlta (7.8)—

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

f2fs: fix to do sanity check on direct node in truncate_dnode()

syzbot reports below bug:

The root cause is, inodeA references inodeB via inodeB's ino, once inodeA is truncated, it calls truncate_dnode() to truncate data blocks in inodeB's node page, it traverse mapping data from node->i.i_addr[0] to node->i.i_addr[ADDRS_PER_BLOCK() - 1], result in out-of-boundary access.

This patch fixes to add sanity check on dnode page in truncate_dnode(), so that, it can help to avoid triggering such issue, and once it encounters such issue, it will record newly introduced ERROR_INVALID_NODE_REFERENCE error into superblock, later fsck can detect such issue and try repairing.

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Also, it removes f2fs_truncate_data_blocks() for cleanup due to the function has only one caller, and uses f2fs_truncate_data_blocks_range() instead.

Detalles técnicos trazas, registros y código del informe original
BUG: KASAN: slab-use-after-free in f2fs_truncate_data_blocks_range+0x122a/0x14c0 fs/f2fs/file.c:574
Read of size 4 at addr ffff88802a25c000 by task syz-executor148/5000

CPU: 1 PID: 5000 Comm: syz-executor148 Not tainted 6.4.0-rc7-syzkaller-00041-ge660abd551f1 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106
 print_address_description.constprop.0+0x2c/0x3c0 mm/kasan/report.c:351
 print_report mm/kasan/report.c:462 [inline]
 kasan_report+0x11c/0x130 mm/kasan/report.c:572
 f2fs_truncate_data_blocks_range+0x122a/0x14c0 fs/f2fs/file.c:574
 truncate_dnode+0x229/0x2e0 fs/f2fs/node.c:944
 f2fs_truncate_inode_blocks+0x64b/0xde0 fs/f2fs/node.c:1154
 f2fs_do_truncate_blocks+0x4ac/0xf30 fs/f2fs/file.c:721
 f2fs_truncate_blocks+0x7b/0x300 fs/f2fs/file.c:749
 f2fs_truncate.part.0+0x4a5/0x630 fs/f2fs/file.c:799
 f2fs_truncate include/linux/fs.h:825 [inline]
 f2fs_setattr+0x1738/0x2090 fs/f2fs/file.c:1006
 notify_change+0xb2c/0x1180 fs/attr.c:483
 do_truncate+0x143/0x200 fs/open.c:66
 handle_truncate fs/namei.c:3295 [inline]
 do_open fs/namei.c:3640 [inline]
 path_openat+0x2083/0x2750 fs/namei.c:3791
 do_filp_open+0x1ba/0x410 fs/namei.c:3818
 do_sys_openat2+0x16d/0x4c0 fs/open.c:1356
 do_sys_open fs/open.c:1372 [inline]
 __do_sys_creat fs/open.c:1448 [inline]
 __se_sys_creat fs/open.c:1442 [inline]
 __x64_sys_creat+0xcd/0x120 fs/open.c:1442
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

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 de escalada de privilegios (AV:L, PR:L) en kernel Linux f2fs con impacto de confidencialidad, integridad y disponibilidad. El defecto permite acceso fuera de límites a datos de inodos causando corrupción de memoria (use-after-free).

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-2023-53846",
  "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": "98e4da8ca301e062d79ae168c67e56f3c3de3ce4",
              "lessThan": "af0f716ad3b039cab9d426da63a5ee6c88751185",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "98e4da8ca301e062d79ae168c67e56f3c3de3ce4",
              "lessThan": "a6ec83786ab9f13f25fb18166dee908845713a95",
              "versionType": "git"
            }
          ],
          "programFiles": [
            "fs/f2fs/f2fs.h",
            "fs/f2fs/file.c",
            "fs/f2fs/node.c",
            "include/linux/f2fs_fs.h"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "3.8"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "3.8",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "6.4.10",
              "versionType": "semver",
              "lessThanOrEqual": "6.4.*"
            },
            {
              "status": "unaffected",
              "version": "6.5",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "fs/f2fs/f2fs.h",
            "fs/f2fs/file.c",
            "fs/f2fs/node.c",
            "include/linux/f2fs_fs.h"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2025-12-09T16:17:25.003",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/a6ec83786ab9f13f25fb18166dee908845713a95",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/af0f716ad3b039cab9d426da63a5ee6c88751185",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Deferred",
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: fix to do sanity check on direct node in truncate_dnode()\n\nsyzbot reports below bug:\n\nBUG: KASAN: slab-use-after-free in f2fs_truncate_data_blocks_range+0x122a/0x14c0 fs/f2fs/file.c:574\nRead of size 4 at addr ffff88802a25c000 by task syz-executor148/5000\n\nCPU: 1 PID: 5000 Comm: syz-executor148 Not tainted 6.4.0-rc7-syzkaller-00041-ge660abd551f1 #0\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023\nCall Trace:\n <TASK>\n __dump_stack lib/dump_stack.c:88 [inline]\n dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106\n print_address_description.constprop.0+0x2c/0x3c0 mm/kasan/report.c:351\n print_report mm/kasan/report.c:462 [inline]\n kasan_report+0x11c/0x130 mm/kasan/report.c:572\n f2fs_truncate_data_blocks_range+0x122a/0x14c0 fs/f2fs/file.c:574\n truncate_dnode+0x229/0x2e0 fs/f2fs/node.c:944\n f2fs_truncate_inode_blocks+0x64b/0xde0 fs/f2fs/node.c:1154\n f2fs_do_truncate_blocks+0x4ac/0xf30 fs/f2fs/file.c:721\n f2fs_truncate_blocks+0x7b/0x300 fs/f2fs/file.c:749\n f2fs_truncate.part.0+0x4a5/0x630 fs/f2fs/file.c:799\n f2fs_truncate include/linux/fs.h:825 [inline]\n f2fs_setattr+0x1738/0x2090 fs/f2fs/file.c:1006\n notify_change+0xb2c/0x1180 fs/attr.c:483\n do_truncate+0x143/0x200 fs/open.c:66\n handle_truncate fs/namei.c:3295 [inline]\n do_open fs/namei.c:3640 [inline]\n path_openat+0x2083/0x2750 fs/namei.c:3791\n do_filp_open+0x1ba/0x410 fs/namei.c:3818\n do_sys_openat2+0x16d/0x4c0 fs/open.c:1356\n do_sys_open fs/open.c:1372 [inline]\n __do_sys_creat fs/open.c:1448 [inline]\n __se_sys_creat fs/open.c:1442 [inline]\n __x64_sys_creat+0xcd/0x120 fs/open.c:1442\n do_syscall_x64 arch/x86/entry/common.c:50 [inline]\n do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80\n entry_SYSCALL_64_after_hwframe+0x63/0xcd\n\nThe root cause is, inodeA references inodeB via inodeB's ino, once inodeA\nis truncated, it calls truncate_dnode() to truncate data blocks in inodeB's\nnode page, it traverse mapping data from node->i.i_addr[0] to\nnode->i.i_addr[ADDRS_PER_BLOCK() - 1], result in out-of-boundary access.\n\nThis patch fixes to add sanity check on dnode page in truncate_dnode(),\nso that, it can help to avoid triggering such issue, and once it encounters\nsuch issue, it will record newly introduced ERROR_INVALID_NODE_REFERENCE\nerror into superblock, later fsck can detect such issue and try repairing.\n\nAlso, it removes f2fs_truncate_data_blocks() for cleanup due to the\nfunction has only one caller, and uses f2fs_truncate_data_blocks_range()\ninstead."
    }
  ],
  "lastModified": "2026-08-04T10:19:23.927",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}