{"id":"CVE-2026-98723","summary":"nvmet: copy the hostid into the ctrl before creating PR pc_refs","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nnvmet: copy the hostid into the ctrl before creating PR pc_refs\n\nCommit 6202783184bf (\"nvmet: Improve nvmet_alloc_ctrl() interface and\nimplementation\") added a second uuid_copy() of args-\u003ehostid near the end\nof nvmet_alloc_ctrl(), and commit 7b658153f1b8 (\"nvmet: Remove duplicate\nuuid_copy\") removed the original copy that sat before\nnvmet_ctrl_init_pr() instead of the new one.\n\nSince then nvmet_ctrl_init_pr() snapshots ctrl-\u003ehostid into the\nper-controller per-namespace reservation refs while the uuid_copy()\nfrom the connect data runs later, after the controller is published.\nThe ctrl is allocated with kzalloc(), so every pc_ref created on this\npath stores the nil UUID.\n\npc_ref-\u003ehostid has a single consumer: nvmet_pr_set_ctrl_to_abort()\nmatches it against the preempted registrant's hostid to kill and drain\nthe victim's in-flight I/O for Preempt and Abort.  The match can never\nhit with the nil UUID, so whenever a namespace with reservations\nenabled exists before a host connects, which includes every reconnect,\nPreempt and Abort silently degrades into a plain Preempt: the\npreempting host sees success while the victim's in-flight I/O is still\nin the air.\n\nCopy the hostid where the rest of the connect data is consumed, before\nthe controller is published and before nvmet_ctrl_init_pr() takes its\nsnapshot.","modified":"2026-10-20T02:30:26.414083149Z","published":"2026-10-18T15:46:59.444Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98723.json","cna_assigner":"Linux"},"references":[{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"},{"type":"WEB","url":"https://git.kernel.org/stable/c/23194531595c5d1d4454e3a607b0c8fc0c4e8695"},{"type":"WEB","url":"https://git.kernel.org/stable/c/5211fed41d7ec90e9ab7239dc4bffffe4d0b2b62"},{"type":"WEB","url":"https://git.kernel.org/stable/c/d3d6d7efdacc08616d23b3ac42272a494951dc0f"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98723.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98723"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"7b658153f1b8a79ed98980f2fef7b92a66aeb9cd"},{"fixed":"d3d6d7efdacc08616d23b3ac42272a494951dc0f"},{"fixed":"23194531595c5d1d4454e3a607b0c8fc0c4e8695"},{"fixed":"5211fed41d7ec90e9ab7239dc4bffffe4d0b2b62"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98723.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.15.0"},{"fixed":"6.18.56"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.2.10"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98723.json"}}],"schema_version":"1.9.0"}