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GHSA-4WQV-WRMF-6H4V

Vulnerability from github – Published: 2026-09-11 21:31 – Updated: 2026-09-14 15:32
VLAI
Details

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

ata: libata-scsi: fix DSM TRIM for sector sizes larger than 2048 bytes

ata_scsi_write_same_xlat() translates a SCSI WRITE SAME command with the UNMAP bit set into an ATA DATA SET MANAGEMENT TRIM command. The TRIM descriptor is built by ata_format_dsm_trim_descr() into the 2048-byte ata_scsi_rbuf staging buffer, and the number of bytes copied is compared against the logical sector size by the caller:

size = ata_format_dsm_trim_descr(scmd, trmax, block, n_block);
if (size != len)        /* len == sdp->sector_size */
    goto invalid_param_len;

ata_format_dsm_trim_descr() clamps the copy length to ATA_SCSI_RBUF_SIZE (2048). On a device whose logical sector size exceeds that (e.g. a 4Kn device, where sector_size == 4096) the function can never return more than 2048, while the caller expects it to return sector_size. The comparison therefore always fails, so every TRIM is rejected with "Parameter list length error" and WARN_ON() splats on each attempt. TRIM / discard is thus completely broken on such devices.

The descriptor was incorrectly sized from the logical sector size. A DSM TRIM payload is a list of 512-byte pages, each holding up to ATA_MAX_TRIM_RNUM (64) LBA Range Entries, and is independent of the logical sector size. The Block Limits VPD page already advertises a single such page as the maximum WRITE SAME length (65535 * ATA_MAX_TRIM_RNUM logical blocks), so the block layer never sends a request that needs more than one page.

Emit exactly one 512-byte page, independent of the logical sector size, and transfer only that page (COUNT == 1). For a 512-byte-sector device this is unchanged; devices with larger logical sectors now work instead of failing every TRIM.

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2026-89586"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-11T20:19:43Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nata: libata-scsi: fix DSM TRIM for sector sizes larger than 2048 bytes\n\nata_scsi_write_same_xlat() translates a SCSI WRITE SAME command with the\nUNMAP bit set into an ATA DATA SET MANAGEMENT TRIM command.  The TRIM\ndescriptor is built by ata_format_dsm_trim_descr() into the 2048-byte\nata_scsi_rbuf staging buffer, and the number of bytes copied is compared\nagainst the logical sector size by the caller:\n\n\tsize = ata_format_dsm_trim_descr(scmd, trmax, block, n_block);\n\tif (size != len)\t\t/* len == sdp-\u003esector_size */\n\t\tgoto invalid_param_len;\n\nata_format_dsm_trim_descr() clamps the copy length to ATA_SCSI_RBUF_SIZE\n(2048).  On a device whose logical sector size exceeds that (e.g. a 4Kn\ndevice, where sector_size == 4096) the function can never return more than\n2048, while the caller expects it to return sector_size.  The comparison\ntherefore always fails, so every TRIM is rejected with \"Parameter list\nlength error\" and WARN_ON() splats on each attempt.  TRIM / discard is\nthus completely broken on such devices.\n\nThe descriptor was incorrectly sized from the logical sector size.  A DSM\nTRIM payload is a list of 512-byte pages, each holding up to\nATA_MAX_TRIM_RNUM (64) LBA Range Entries, and is independent of the logical\nsector size.  The Block Limits VPD page already advertises a single such\npage as the maximum WRITE SAME length (65535 * ATA_MAX_TRIM_RNUM logical\nblocks), so the block layer never sends a request that needs more than one\npage.\n\nEmit exactly one 512-byte page, independent of the logical sector size,\nand transfer only that page (COUNT == 1).  For a 512-byte-sector device\nthis is unchanged; devices with larger logical sectors now work instead of\nfailing every TRIM.",
  "id": "GHSA-4wqv-wrmf-6h4v",
  "modified": "2026-09-14T15:32:30Z",
  "published": "2026-09-11T21:31:33Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-89586"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/04e2befe25792f2e90097f284d7e86fc6bcfe928"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/07975b8daa3b0ab3cbc02cc48ea7bc48fadcec53"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/07baa310ea3224a7044b1ca84796bb37a235af1f"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/4a4268a0b0a595bd9534cf9c7fda93775a7d8a0d"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/79cce911e623c0baa0fde307ce3a434e084b881a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/977554ed91b54075fbc0bac536316b4841ef6258"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/b7b5ab2df325ffbbad7ca2debaa071e024d68cb5"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c2e3dccd6870659851eaa4c12ab16418b8e3040a"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}



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