{
  "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-2021-47636",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2021-47636",
    "idYear": 2021,
    "status": "PUBLISHED",
    "publishedAt": "2025-02-26T01:54:10.206Z",
    "updatedAt": "2026-08-05T08:48:42.752Z",
    "importedAt": "2026-10-24T01:56:36.661Z",
    "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": "ubifs: Fix read out-of-bounds in ubifs_wbuf_write_nolock()",
      "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nubifs: Fix read out-of-bounds in ubifs_wbuf_write_nolock()\n\nFunction ubifs_wbuf_write_nolock() may access buf out of bounds in\nfollowing process:\n\nubifs_wbuf_write_nolock():\n  aligned_len = ALIGN(len, 8);   // Assume len = 4089, aligned_len = 4096\n  if (aligned_len <= wbuf->avail) ... // Not satisfy\n  if (wbuf->used) {\n    ubifs_leb_write()  // Fill some data in avail wbuf\n    len -= wbuf->avail;   // len is still not 8-bytes aligned\n    aligned_len -= wbuf->avail;\n  }\n  n = aligned_len >> c->max_write_shift;\n  if (n) {\n    n <<= c->max_write_shift;\n    err = ubifs_leb_write(c, wbuf->lnum, buf + written,\n                          wbuf->offs, n);\n    // n > len, read out of bounds less than 8(n-len) bytes\n  }\n\n, which can be catched by KASAN:\n  =========================================================\n  BUG: KASAN: slab-out-of-bounds in ecc_sw_hamming_calculate+0x1dc/0x7d0\n  Read of size 4 at addr ffff888105594ff8 by task kworker/u8:4/128\n  Workqueue: writeback wb_workfn (flush-ubifs_0_0)\n  Call Trace:\n    kasan_report.cold+0x81/0x165\n    nand_write_page_swecc+0xa9/0x160\n    ubifs_leb_write+0xf2/0x1b0 [ubifs]\n    ubifs_wbuf_write_nolock+0x421/0x12c0 [ubifs]\n    write_head+0xdc/0x1c0 [ubifs]\n    ubifs_jnl_write_inode+0x627/0x960 [ubifs]\n    wb_workfn+0x8af/0xb80\n\nFunction ubifs_wbuf_write_nolock() accepts that parameter 'len' is not 8\nbytes aligned, the 'len' represents the true length of buf (which is\nallocated in 'ubifs_jnl_xxx', eg. ubifs_jnl_write_inode), so\nubifs_wbuf_write_nolock() must handle the length read from 'buf' carefully\nto write leb safely.\n\nFetch a reproducer in [Link].",
      "affected": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "1e51764a3c2ac05a23a22b2a95ddee4d9bffb16d",
              "status": "affected",
              "versionType": "git",
              "lessThan": "5343575aa11c5d7044107d59d43f84aec01312b0"
            },
            {
              "version": "1e51764a3c2ac05a23a22b2a95ddee4d9bffb16d",
              "status": "affected",
              "versionType": "git",
              "lessThan": "b80ccbec0e4804436c382d7dd60e943c386ed83a"
            },
            {
              "version": "1e51764a3c2ac05a23a22b2a95ddee4d9bffb16d",
              "status": "affected",
              "versionType": "git",
              "lessThan": "07a209fadee7b53b46858538e1177597273862e4"
            },
            {
              "version": "1e51764a3c2ac05a23a22b2a95ddee4d9bffb16d",
              "status": "affected",
              "versionType": "git",
              "lessThan": "a7054aaf1909cf40489c0ec1b728fdcf79c751a6"
            },
            {
              "version": "1e51764a3c2ac05a23a22b2a95ddee4d9bffb16d",
              "status": "affected",
              "versionType": "git",
              "lessThan": "e09fa5318d51f522e1af4fbaf8f74999355980c8"
            },
            {
              "version": "1e51764a3c2ac05a23a22b2a95ddee4d9bffb16d",
              "status": "affected",
              "versionType": "git",
              "lessThan": "3b7fb89135a20587d57f8877c02e25003e9edbdf"
            },
            {
              "version": "1e51764a3c2ac05a23a22b2a95ddee4d9bffb16d",
              "status": "affected",
              "versionType": "git",
              "lessThan": "4f2262a334641e05f645364d5ade1f565c85f20b"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "versions": [
            {
              "version": "2.6.27",
              "status": "affected"
            },
            {
              "version": "0",
              "status": "unaffected",
              "versionType": "semver",
              "lessThan": "2.6.27"
            },
            {
              "version": "4.19.238",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "4.19.*"
            },
            {
              "version": "5.4.189",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.4.*"
            },
            {
              "version": "5.10.110",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.10.*"
            },
            {
              "version": "5.15.33",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.15.*"
            },
            {
              "version": "5.16.19",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.16.*"
            },
            {
              "version": "5.17.2",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.17.*"
            },
            {
              "version": "5.18",
              "status": "unaffected",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ]
        }
      ]
    }
  }
}