CVE-2026-93050

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: ipack: ipoctal: fix UAF, null-ptr-deref, and use-after-free in cleanup on remove Three issues arise when the device is removed while a tty session is still active: 1. UAF of struct ipoctal: the remove callback frees ipoctal via kfree() while tty ops may still access it. Fix by introducing kref-based lifetime management — kref is taken in install() when a tty is opened and released in cleanup() when the tty is finally destroyed; remove() uses kref_put() instead of kfree(). 2. NULL dereference in ipoctal_write_tty(): __ipoctal_remove() frees xmit_buf via tty_port_free_xmit_buf() while a userspace process may still hold the tty fd and call write(). Fix by checking for NULL xmit_buf in ipoctal_write_tty(). 3. UAF in ipoctal_cleanup(): ipack_put_carrier(ipoctal->dev) dereferences ipoctal->dev after the ipack_device has been freed by ipack_device_del(). Fix by caching ipoctal->carrier_owner during probe() and calling module_put() on the cached pointer directly in cleanup(), avoiding any access to ipoctal->dev. Also introduce a "removed" flag in struct ipoctal, set at the start of __ipoctal_remove(), and checked in every tty op that accesses hardware resources (port_activate, write_tty, set_termios, hangup, shutdown). This prevents page faults when devm_ioremap() regions are unmapped after remove() returns.

Severity

Not scored

CVSS score

Not available

Vulnerability status

Received

Source identifier

416baaa9-dc9f-4396-8d5f-8c081fb06d67

Published

2026-09-17 17:17:58.367000

Last modified

2026-10-19 10:16:54.790000

View original CVE JSON

{
  "id": "CVE-2026-93050",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-09-17T17:17:58.367",
  "lastModified": "2026-10-19T10:16:54.790",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nipack: ipoctal: fix UAF, null-ptr-deref, and use-after-free in cleanup on remove\n\nThree issues arise when the device is removed while a tty session is\nstill active:\n\n1. UAF of struct ipoctal: the remove callback frees ipoctal via\n   kfree() while tty ops may still access it.  Fix by introducing\n   kref-based lifetime management — kref is taken in install() when\n   a tty is opened and released in cleanup() when the tty is finally\n   destroyed; remove() uses kref_put() instead of kfree().\n\n2. NULL dereference in ipoctal_write_tty(): __ipoctal_remove()\n   frees xmit_buf via tty_port_free_xmit_buf() while a userspace\n   process may still hold the tty fd and call write().  Fix by\n   checking for NULL xmit_buf in ipoctal_write_tty().\n\n3. UAF in ipoctal_cleanup(): ipack_put_carrier(ipoctal->dev)\n   dereferences ipoctal->dev after the ipack_device has been freed\n   by ipack_device_del().  Fix by caching ipoctal->carrier_owner\n   during probe() and calling module_put() on the cached pointer\n   directly in cleanup(), avoiding any access to ipoctal->dev.\n\nAlso introduce a \"removed\" flag in struct ipoctal, set at the start\nof __ipoctal_remove(), and checked in every tty op that accesses\nhardware resources (port_activate, write_tty, set_termios, hangup,\nshutdown).  This prevents page faults when devm_ioremap() regions\nare unmapped after remove() returns."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "drivers/ipack/devices/ipoctal.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "05e5027efc9c0bb6d1d04cde279afbafca0a7929",
              "lessThan": "ab5f5b27a340004b92252c6a5f23bf1c6cf3b02a",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "05e5027efc9c0bb6d1d04cde279afbafca0a7929",
              "lessThan": "c92ef8fd834521f0b788e0511976c689fe57c63c",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "05e5027efc9c0bb6d1d04cde279afbafca0a7929",
              "lessThan": "a4613140f01bd0fb9980e2746ed9aaa65a29b5d6",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "05e5027efc9c0bb6d1d04cde279afbafca0a7929",
              "lessThan": "1a3258e105f711538201bdd2ac2a05b11554eabc",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "05e5027efc9c0bb6d1d04cde279afbafca0a7929",
              "lessThan": "4a6518be316029650301f2a5e8f0def229b895d9",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "05e5027efc9c0bb6d1d04cde279afbafca0a7929",
              "lessThan": "b6b5d64cb161a28347d64dc3168a636c4abb68d5",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "drivers/ipack/devices/ipoctal.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "3.8",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "3.8",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.1.188",
              "lessThanOrEqual": "6.1.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.6.157",
              "lessThanOrEqual": "6.6.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.12.110",
              "lessThanOrEqual": "6.12.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.52",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2.6",
              "lessThanOrEqual": "7.2.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.3",
              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {},
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/1a3258e105f711538201bdd2ac2a05b11554eabc",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/4a6518be316029650301f2a5e8f0def229b895d9",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/a4613140f01bd0fb9980e2746ed9aaa65a29b5d6",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/ab5f5b27a340004b92252c6a5f23bf1c6cf3b02a",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/b6b5d64cb161a28347d64dc3168a636c4abb68d5",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/c92ef8fd834521f0b788e0511976c689fe57c63c",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}