{"id":"CVE-2026-98723","title":"nvmet: copy the hostid into the ctrl before creating PR pc_refs","summary":"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 u…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 7b658153f1b8a79ed98980f2fef7b92a66aeb9cd < d3d6d7efdacc08616d23b3ac42272a494951dc0f","Linux >= 7b658153f1b8a79ed98980f2fef7b92a66aeb9cd < 23194531595c5d1d4454e3a607b0c8fc0c4e8695","Linux >= 7b658153f1b8a79ed98980f2fef7b92a66aeb9cd < 5211fed41d7ec90e9ab7239dc4bffffe4d0b2b62","Linux 6.15"],"published":"2026-10-18","updated":"2026-10-18","sourceUpdated":"2026-10-18T15:46:59.444Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-98723","references":[{"url":"https://git.kernel.org/stable/c/d3d6d7efdacc08616d23b3ac42272a494951dc0f"},{"url":"https://git.kernel.org/stable/c/23194531595c5d1d4454e3a607b0c8fc0c4e8695"},{"url":"https://git.kernel.org/stable/c/5211fed41d7ec90e9ab7239dc4bffffe4d0b2b62"}],"tags":["cve.org"],"ingestedAt":"2026-10-18T16:47:32.508Z","slug":"CVE-2026-98723","body":"## Overview\n\nIn 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->hostid 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->hostid 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->hostid 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.\n\n## Affected\n\n- `Linux >= 7b658153f1b8a79ed98980f2fef7b92a66aeb9cd < d3d6d7efdacc08616d23b3ac42272a494951dc0f`\n- `Linux >= 7b658153f1b8a79ed98980f2fef7b92a66aeb9cd < 23194531595c5d1d4454e3a607b0c8fc0c4e8695`\n- `Linux >= 7b658153f1b8a79ed98980f2fef7b92a66aeb9cd < 5211fed41d7ec90e9ab7239dc4bffffe4d0b2b62`\n- `Linux 6.15`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}