{
  "schemaVersion": 1,
  "attribution": [
    {
      "source": "CISA Known Exploited Vulnerabilities",
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog",
      "licence": "US government work"
    },
    {
      "source": "GitHub Advisory Database",
      "url": "https://github.com/advisories",
      "licence": "CC BY 4.0"
    },
    {
      "source": "Have I Been Pwned",
      "url": "https://haveibeenpwned.com/",
      "licence": "CC BY 4.0"
    },
    {
      "source": "CVE Program (CVE records)",
      "url": "https://www.cve.org/Legal/TermsOfUse",
      "licence": "CVE Terms of Use",
      "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.",
      "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy."
    },
    {
      "source": "FIRST EPSS",
      "url": "https://www.first.org/epss/",
      "licence": "free to use; FIRST requests attribution"
    }
  ],
  "record": {
    "id": "CVE-2022-49850",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2022-49850",
    "idYear": 2022,
    "status": "PUBLISHED",
    "publishedAt": "2025-05-01T14:10:05.167Z",
    "updatedAt": "2026-05-11T19:07:57.952Z",
    "importedAt": "2026-10-24T01:56:49.724Z",
    "snapshot": {
      "id": "cve_2026-10-24_midnight_baseline",
      "at": "2026-10-24T00:00:00.000Z",
      "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z"
    },
    "facts": {
      "title": "nilfs2: fix deadlock in nilfs_count_free_blocks()",
      "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nnilfs2: fix deadlock in nilfs_count_free_blocks()\n\nA semaphore deadlock can occur if nilfs_get_block() detects metadata\ncorruption while locating data blocks and a superblock writeback occurs at\nthe same time:\n\ntask 1                               task 2\n------                               ------\n* A file operation *\nnilfs_truncate()\n  nilfs_get_block()\n    down_read(rwsem A) <--\n    nilfs_bmap_lookup_contig()\n      ...                            generic_shutdown_super()\n                                       nilfs_put_super()\n                                         * Prepare to write superblock *\n                                         down_write(rwsem B) <--\n                                         nilfs_cleanup_super()\n      * Detect b-tree corruption *         nilfs_set_log_cursor()\n      nilfs_bmap_convert_error()             nilfs_count_free_blocks()\n        __nilfs_error()                        down_read(rwsem A) <--\n          nilfs_set_error()\n            down_write(rwsem B) <--\n\n                           *** DEADLOCK ***\n\nHere, nilfs_get_block() readlocks rwsem A (= NILFS_MDT(dat_inode)->mi_sem)\nand then calls nilfs_bmap_lookup_contig(), but if it fails due to metadata\ncorruption, __nilfs_error() is called from nilfs_bmap_convert_error()\ninside the lock section.\n\nSince __nilfs_error() calls nilfs_set_error() unless the filesystem is\nread-only and nilfs_set_error() attempts to writelock rwsem B (=\nnilfs->ns_sem) to write back superblock exclusively, hierarchical lock\nacquisition occurs in the order rwsem A -> rwsem B.\n\nNow, if another task starts updating the superblock, it may writelock\nrwsem B during the lock sequence above, and can deadlock trying to\nreadlock rwsem A in nilfs_count_free_blocks().\n\nHowever, there is actually no need to take rwsem A in\nnilfs_count_free_blocks() because it, within the lock section, only reads\na single integer data on a shared struct with\nnilfs_sufile_get_ncleansegs().  This has been the case after commit\naa474a220180 (\"nilfs2: add local variable to cache the number of clean\nsegments\"), that is, even before this bug was introduced.\n\nSo, this resolves the deadlock problem by just not taking the semaphore in\nnilfs_count_free_blocks().",
      "affected": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "e828949e5b42bfd234ee537cdb7c5e3a577958a3",
              "status": "affected",
              "versionType": "git",
              "lessThan": "3c89ca6d3dfa6c09c515807a7a97a521f5d5147e"
            },
            {
              "version": "e828949e5b42bfd234ee537cdb7c5e3a577958a3",
              "status": "affected",
              "versionType": "git",
              "lessThan": "8b4506cff6630bb474bb46a2a75c31e533a756ba"
            },
            {
              "version": "e828949e5b42bfd234ee537cdb7c5e3a577958a3",
              "status": "affected",
              "versionType": "git",
              "lessThan": "f0cc93080d4c09510b74ecba87fd778cca390bb1"
            },
            {
              "version": "e828949e5b42bfd234ee537cdb7c5e3a577958a3",
              "status": "affected",
              "versionType": "git",
              "lessThan": "36ff974b0310771417c0be64b64aa221bd70d63d"
            },
            {
              "version": "e828949e5b42bfd234ee537cdb7c5e3a577958a3",
              "status": "affected",
              "versionType": "git",
              "lessThan": "1d4ff73062096c21b47954d2996b4df259777bda"
            },
            {
              "version": "e828949e5b42bfd234ee537cdb7c5e3a577958a3",
              "status": "affected",
              "versionType": "git",
              "lessThan": "abc082aac0d9b6b926038fc3adb7008306581be2"
            },
            {
              "version": "e828949e5b42bfd234ee537cdb7c5e3a577958a3",
              "status": "affected",
              "versionType": "git",
              "lessThan": "cb029b54953420f7a2d65100f1c5107f14411bdc"
            },
            {
              "version": "e828949e5b42bfd234ee537cdb7c5e3a577958a3",
              "status": "affected",
              "versionType": "git",
              "lessThan": "8ac932a4921a96ca52f61935dbba64ea87bbd5dc"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "versions": [
            {
              "version": "2.6.38",
              "status": "affected"
            },
            {
              "version": "0",
              "status": "unaffected",
              "versionType": "semver",
              "lessThan": "2.6.38"
            },
            {
              "version": "4.9.334",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "4.9.*"
            },
            {
              "version": "4.14.300",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "4.14.*"
            },
            {
              "version": "4.19.267",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "4.19.*"
            },
            {
              "version": "5.4.225",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.4.*"
            },
            {
              "version": "5.10.155",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.10.*"
            },
            {
              "version": "5.15.79",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.15.*"
            },
            {
              "version": "6.0.9",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.0.*"
            },
            {
              "version": "6.1",
              "status": "unaffected",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ]
        }
      ]
    }
  }
}