{
  "cveId": "CVE-2022-49834",
  "url": "https://patchblox.com/security/cve/CVE-2022-49834",
  "summary": "CVE-2022-49834 is fixed in linux on 1 platform, first by DEBIAN-CVE-2022-49834, released May 1, 2025. It is not reported as exploited. Patch Radar priority: High.",
  "title": "linux: In the Linux kernel, the following vulnerability has been resolved:  nilfs2: fix use-after-free bug of ns_writer on r...",
  "description": "In the Linux kernel, the following vulnerability has been resolved:  nilfs2: fix use-after-free bug of ns_writer on remount  If a nilfs2 filesystem is downgraded to read-only due to metadata corruption on disk and is remounted read/write, or if emergency read-only remount is performed, detaching a log writer and synchronizing the filesystem can be done at the same time.  In these cases, use-after-free of the log writer (hereinafter nilfs-\u003Ens_writer) can happen as shown in the scenario below:   Task1                               Task2  --------------------------------    ------------------------------  nilfs_construct_segment    nilfs_segctor_sync      init_wait      init_waitqueue_entry      add_wait_queue      schedule                                      nilfs_remount (R/W remount case) \t\t\t\t       nilfs_attach_log_writer                                          nilfs_detach_log_writer                                            nilfs_segctor_destroy                                              kfree      finish_wait        _raw_spin_lock_irqsave          __raw_spin_lock_irqsave            do_raw_spin_lock              debug_spin_lock_before  \u003C-- use-after-free  While Task1 is sleeping, nilfs-\u003Ens_writer is freed by Task2.  After Task1 waked up, Task1 accesses nilfs-\u003Ens_writer which is already freed.  This scenario diagram is based on the Shigeru Yoshida\u0027s post [1].  This patch fixes the issue by not detaching nilfs-\u003Ens_writer on remount so that this UAF race doesn\u0027t happen.  Along with this change, this patch also inserts a few necessary read-only checks with superblock instance where only the ns_writer pointer was used to check if the filesystem is read-only.",
  "published": "2025-05-01T15:16:06Z",
  "severity": "high",
  "cvss": 7.8,
  "cvssVector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
  "epss": 0.00223,
  "epssPercentile": 0.1302,
  "priority": "High",
  "priorityTier": 3,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 12.15 (bookworm)",
      "fixedVersion": "6.0.10-1",
      "fix": "DEBIAN-CVE-2022-49834",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2022-49834",
      "released": "2025-05-01T15:16:06Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 13.5 (trixie)",
      "fixedVersion": "6.0.10-1",
      "fix": "DEBIAN-CVE-2022-49834",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2022-49834",
      "released": "2025-05-01T15:16:06Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 14",
      "fixedVersion": "6.0.10-1",
      "fix": "DEBIAN-CVE-2022-49834",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2022-49834",
      "released": "2025-05-01T15:16:06Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-08T13:06:02Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}