{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "1a31368bf92ef2a7da3ba379672c405bd2751df9"
            },
            {
              "fixed": "701c3ae7273e1adc20db5d97c42e0139b479f16b"
            },
            {
              "fixed": "6aaab2ace3f7b55733d904e5549acf8405f03642"
            },
            {
              "fixed": "181c1bff940e7d3e34ca485d37e3cdbfe409203c"
            },
            {
              "fixed": "a536eb57be58442b19398b2783071007ecfb1735"
            },
            {
              "fixed": "e204e5c49a012f99638633fdbd773e3c86260053"
            },
            {
              "fixed": "398aca2f90122d5abbabff1079deaeb885fe9e40"
            },
            {
              "fixed": "c645f6dd1af2ecc70fd3578e141f2f71fa9e4eff"
            },
            {
              "fixed": "b759d5bb6265419344ee9729fd0dc07ad85719d8"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "3.2.0"
            },
            {
              "fixed": "5.10.270"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.11.0"
            },
            {
              "fixed": "5.15.221"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.16.0"
            },
            {
              "fixed": "6.1.188"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.2.0"
            },
            {
              "fixed": "6.6.157"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.12.110"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.52"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.2.6"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/93xxx/CVE-2026-93048.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nmtd: part: reject MTDPART_OFS_RETAIN in mtd_add_partition()\n\nmtd_add_partition() does not reject the special offset value\nMTDPART_OFS_RETAIN (-3), which leads to a WARN_ON in\nadd_mtd_device() when called through the BLKPG ioctl on NAND\ndevices. The RETAIN value depends on cur_offset being the end of\nthe previous partition, but in the dynamic partition path\ncur_offset equals the offset argument itself, causing undefined\nbehavior.\n\nCommit 5daa7b21496a (\"mtd: prepare partition add and del functions\nfor ioctl requests\") introduced mtd_add_partition() and correctly\nrejected MTDPART_OFS_APPEND (-1) and MTDPART_OFS_NXTBLK (-2),\nsince those special offsets rely on cur_offset tracking the\nprevious partition's end. However, commit 1a31368bf92e (\"mtd: add a flags\nfor partitions which should just leave smth. after them\")\nlater added MTDPART_OFS_RETAIN (-3) for the static\npartition table path without updating mtd_add_partition() to\nalso reject this value.\n\nWith offset=-3 passed via BLKPG, the RETAIN size calculation in\nallocate_partition() underflows (parent_size - 0xFFFFFFFFFFFFFFFD\n= parent_size + 3). If the underflow result does not appear to\nleave enough space, allocate_partition() jumps to out_register via\ngoto, skipping erasesize initialization. This results in\nerasesize=0, which triggers:\n\nWARN_ON((!mtd-\u003eerasesize || !master-\u003e_erase) \u0026\u0026\n\t\t!(mtd-\u003eflags \u0026 MTD_NO_ERASE))\n\nin add_mtd_device(). If the underflow result appears to leave\nenough space, a bogus partition size is calculated, but the\n\"out of reach\" sanity check catches the invalid offset and\ncreates a disabled empty partition (offset=0, size=0) instead\nof returning an error.\n\nFix this by adding MTDPART_OFS_RETAIN to the rejection list in\nmtd_add_partition(), consistent with the existing handling of\nAPPEND and NXTBLK.",
  "id": "CVE-2026-93048",
  "modified": "2026-09-19T03:30:21.121186130Z",
  "published": "2026-09-17T16:10:39.008Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/181c1bff940e7d3e34ca485d37e3cdbfe409203c"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/398aca2f90122d5abbabff1079deaeb885fe9e40"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/6aaab2ace3f7b55733d904e5549acf8405f03642"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/701c3ae7273e1adc20db5d97c42e0139b479f16b"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a536eb57be58442b19398b2783071007ecfb1735"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/b759d5bb6265419344ee9729fd0dc07ad85719d8"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c645f6dd1af2ecc70fd3578e141f2f71fa9e4eff"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e204e5c49a012f99638633fdbd773e3c86260053"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/93xxx/CVE-2026-93048.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-93048"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.9.0",
  "summary": "mtd: part: reject MTDPART_OFS_RETAIN in mtd_add_partition()"
}