CVE-2026-68455 (GCVE-0-2026-68455)

Vulnerability from cvelistv5 – Published: 2026-08-15 05:51 – Updated: 2026-08-17 05:05
VLAI
Title
liveupdate: validate session type before performing operation
Summary
In the Linux kernel, the following vulnerability has been resolved: liveupdate: validate session type before performing operation The sessions ioctls are not applicable to all session types. PRESERVE_FD is only applicable to outgoing sessions. RETRIEVE_FD and FINISH are only valid for incoming session. Calling a incoming ioctl on an outgoing session is invalid and can cause file handlers to run into unexpected errors. For example, a user can create a (outgoing) session, preserve a memfd, and then immediately do a retrieve without doing a kexec in between. This would result in memfd's retrieve handler to run. The handlers expects to be called from a post-kexec context, and will try to do a kho_restore_vmalloc() or kho_restore_folio() to try and restore memory. KHO catches this (thanks to KHO_PAGE_MAGIC) and returns an error, but since this is considered an internal error and KHO throws out a bunch of WARN()s. Associate a type with each ioctl op and validate the type in luo_session_ioctl() before dispatching the ioctl handler to make sure the op is being called for the right session type.
Severity
No CVSS data available.
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 16cec0d265219f14a7fcebcc43aeb69205adba56 , < 3dc8a46d08a8a060d4128e9f497060b8d03c1595 (git)
Affected: 16cec0d265219f14a7fcebcc43aeb69205adba56 , < 507e3b479f9c6d85135eb5e1a77fb3fddb259ad8 (git)
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Linux Linux Affected: 6.19
Unaffected: 0 , < 6.19 (semver)
Unaffected: 7.1.5 , ≤ 7.1.* (semver)
Unaffected: 7.2 , ≤ * (original_commit_for_fix)
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          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nliveupdate: validate session type before performing operation\n\nThe sessions ioctls are not applicable to all session types. PRESERVE_FD\nis only applicable to outgoing sessions. RETRIEVE_FD and FINISH are only\nvalid for incoming session. Calling a incoming ioctl on an outgoing\nsession is invalid and can cause file handlers to run into unexpected\nerrors.\n\nFor example, a user can create a (outgoing) session, preserve a memfd,\nand then immediately do a retrieve without doing a kexec in between.\nThis would result in memfd\u0027s retrieve handler to run. The handlers\nexpects to be called from a post-kexec context, and will try to do a\nkho_restore_vmalloc() or kho_restore_folio() to try and restore memory.\n\nKHO catches this (thanks to KHO_PAGE_MAGIC) and returns an error, but\nsince this is considered an internal error and KHO throws out a bunch of\nWARN()s.\n\nAssociate a type with each ioctl op and validate the type in\nluo_session_ioctl() before dispatching the ioctl handler to make sure\nthe op is being called for the right session type."
        }
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        "dateUpdated": "2026-08-17T05:05:55.589Z",
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    "datePublished": "2026-08-15T05:51:16.745Z",
    "dateReserved": "2026-07-30T09:28:09.395Z",
    "dateUpdated": "2026-08-17T05:05:55.589Z",
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      "source": "Red Hat CSAF VEX",
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      "title": "kernel: liveupdate: validate session type before performing operation",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-68455.json",
      "version": "3"
    }
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}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
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  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
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  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


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