{"id":"CVE-2026-68455","state":"PUBLISHED","title":"liveupdate: validate session type before performing operation","description":"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's 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.","publishedAt":"2026-08-15T05:51:16.745Z","updatedAt":"2026-08-17T05:05:55.589Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"16cec0d265219f14a7fcebcc43aeb69205adba56","status":"affected","lessThan":"3dc8a46d08a8a060d4128e9f497060b8d03c1595","versionType":"git"},{"version":"16cec0d265219f14a7fcebcc43aeb69205adba56","status":"affected","lessThan":"507e3b479f9c6d85135eb5e1a77fb3fddb259ad8","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/liveupdate/luo_session.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.19","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.19","versionType":"semver"},{"version":"7.1.5","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/liveupdate/luo_session.c"]}],"references":["https://git.kernel.org/stable/c/3dc8a46d08a8a060d4128e9f497060b8d03c1595","https://git.kernel.org/stable/c/507e3b479f9c6d85135eb5e1a77fb3fddb259ad8"],"weaknesses":[],"ingestedAt":"2026-10-29T20:12:49.727Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/68xxx/CVE-2026-68455.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-68455","state":"PUBLISHED","datePublished":"2026-08-15T05:51:16.745Z","dateUpdated":"2026-08-17T05:05:55.589Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-07-30T09:28:09.395Z"},"containers":{"cna":{"title":"liveupdate: validate session type before performing operation","descriptions":[{"lang":"en","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's 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."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"16cec0d265219f14a7fcebcc43aeb69205adba56","status":"affected","lessThan":"3dc8a46d08a8a060d4128e9f497060b8d03c1595","versionType":"git"},{"version":"16cec0d265219f14a7fcebcc43aeb69205adba56","status":"affected","lessThan":"507e3b479f9c6d85135eb5e1a77fb3fddb259ad8","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/liveupdate/luo_session.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.19","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.19","versionType":"semver"},{"version":"7.1.5","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["kernel/liveupdate/luo_session.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/3dc8a46d08a8a060d4128e9f497060b8d03c1595"},{"url":"https://git.kernel.org/stable/c/507e3b479f9c6d85135eb5e1a77fb3fddb259ad8"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-17T05:05:55.589Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.19","versionEndExcluding":"7.1.5"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.19","versionEndExcluding":"7.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}