{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "071cb4b81987a28c7ac2702003cff3e61684a630"
            },
            {
              "fixed": "3ed388ec3b8922383d1e2d4432d7bd4cbbf8364e"
            },
            {
              "fixed": "876c98e0fc65f071680c03c2e2ee3ef7ff9ca078"
            },
            {
              "fixed": "39607452b1400c7bf748f15122df4d058b768c5b"
            },
            {
              "fixed": "286f77d002a337735c0846d7480a82d9cda2aa31"
            },
            {
              "fixed": "0789f0a6710713254a08f3a7d2ecbb6d1cbcf0aa"
            },
            {
              "fixed": "223463c488b0554212a94de971ea538eb2805fc7"
            },
            {
              "fixed": "d26aef771b4f6923da9f89d6d5b70d8def5853de"
            },
            {
              "fixed": "0e7a690fe435f8d5ea3feb7c1d8d73ba7e8b8aa9"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.6.31"
            },
            {
              "fixed": "5.10.261"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.11.0"
            },
            {
              "fixed": "5.15.212"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.16.0"
            },
            {
              "fixed": "6.1.178"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.2.0"
            },
            {
              "fixed": "6.6.145"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.12.96"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.39"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.1.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64359.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnilfs2: reject CLEAN_SEGMENTS ioctl with out-of-range segment numbers\n\nSyzbot reported a hung task in nilfs_transaction_begin() where multiple\ntasks performing chmod() on a nilfs2 mount blocked for over 143 seconds\nwaiting to acquire ns_segctor_sem for read:\n\n  INFO: task syz.0.17:5918 blocked for more than 143 seconds.\n  Call Trace:\n   schedule+0x164/0x360\n   rwsem_down_read_slowpath+0x6d9/0x940\n   down_read+0x99/0x2e0\n   nilfs_transaction_begin+0x364/0x710 fs/nilfs2/segment.c:221\n   nilfs_setattr+0x124/0x2c0 fs/nilfs2/inode.c:921\n   notify_change+0xc1a/0xf40\n   chmod_common+0x273/0x4a0\n   do_fchmodat+0x12d/0x230\n\nThe writer holding ns_segctor_sem was a concurrent\nNILFS_IOCTL_CLEAN_SEGMENTS caller, stuck inside printk while emitting\nper-element warnings from nilfs_sufile_updatev():\n\n   __nilfs_msg+0x373/0x450 fs/nilfs2/super.c:78\n   nilfs_sufile_updatev+0x21c/0x6d0 fs/nilfs2/sufile.c:186\n   nilfs_sufile_freev fs/nilfs2/sufile.h:93 [inline]\n   nilfs_free_segments fs/nilfs2/segment.c:1140 [inline]\n   nilfs_segctor_collect_blocks fs/nilfs2/segment.c:1261 [inline]\n   nilfs_segctor_do_construct+0x1f55/0x76c0\n   nilfs_clean_segments+0x3bd/0xa50\n   nilfs_ioctl_clean_segments fs/nilfs2/ioctl.c:922 [inline]\n   nilfs_ioctl+0x261f/0x2780\n\nThe root cause is that user-supplied segment numbers are not validated\nbefore nilfs_clean_segments() begins doing work; the range check on\neach segnum is performed deep inside the call chain by\nnilfs_sufile_updatev(), which emits a nilfs_warn() per invalid entry\nwhile still holding the segctor lock and the sufile mi_sem.  Under load\n(repeated invocations across multiple mounts saturating the global\nprintk path), the cumulative printk latency keeps ns_segctor_sem held\nlong enough to trip the hung_task watchdog, blocking concurrent\noperations such as chmod() that need ns_segctor_sem for read.\n\nFix by validating the contents of kbufs[4] in nilfs_clean_segments()\nimmediately after acquiring ns_segctor_sem via nilfs_transaction_lock().\nHolding ns_segctor_sem serializes the check against\nnilfs_ioctl_resize(), which can modify ns_nsegments, so the validation\nuses a consistent value.  Out-of-range segment numbers are rejected\nwith -EINVAL before any segment-cleaning work begins, so the bad\nentries never reach the per-element diagnostic path inside\nnilfs_sufile_updatev().",
  "id": "CVE-2026-64359",
  "modified": "2026-09-06T03:30:23.559366458Z",
  "published": "2026-07-25T08:50:15.947Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0789f0a6710713254a08f3a7d2ecbb6d1cbcf0aa"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0e7a690fe435f8d5ea3feb7c1d8d73ba7e8b8aa9"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/223463c488b0554212a94de971ea538eb2805fc7"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/286f77d002a337735c0846d7480a82d9cda2aa31"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/39607452b1400c7bf748f15122df4d058b768c5b"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/3ed388ec3b8922383d1e2d4432d7bd4cbbf8364e"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/876c98e0fc65f071680c03c2e2ee3ef7ff9ca078"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d26aef771b4f6923da9f89d6d5b70d8def5853de"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64359.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-64359"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.9.0",
  "summary": "nilfs2: reject CLEAN_SEGMENTS ioctl with out-of-range segment numbers"
}