{"id":"CVE-2026-98723","state":"PUBLISHED","title":"nvmet: copy the hostid into the ctrl before creating PR pc_refs","description":"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->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.","publishedAt":"2026-10-18T15:46:59.444Z","updatedAt":"2026-10-19T09:24:33.989Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"7b658153f1b8a79ed98980f2fef7b92a66aeb9cd","status":"affected","lessThan":"d3d6d7efdacc08616d23b3ac42272a494951dc0f","versionType":"git"},{"version":"7b658153f1b8a79ed98980f2fef7b92a66aeb9cd","status":"affected","lessThan":"23194531595c5d1d4454e3a607b0c8fc0c4e8695","versionType":"git"},{"version":"7b658153f1b8a79ed98980f2fef7b92a66aeb9cd","status":"affected","lessThan":"5211fed41d7ec90e9ab7239dc4bffffe4d0b2b62","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/nvme/target/core.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.15","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.15","versionType":"semver"},{"version":"6.18.56","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.10","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/nvme/target/core.c"]}],"references":["https://git.kernel.org/stable/c/d3d6d7efdacc08616d23b3ac42272a494951dc0f","https://git.kernel.org/stable/c/23194531595c5d1d4454e3a607b0c8fc0c4e8695","https://git.kernel.org/stable/c/5211fed41d7ec90e9ab7239dc4bffffe4d0b2b62"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:43.249Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/98xxx/CVE-2026-98723.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-98723","state":"PUBLISHED","datePublished":"2026-10-18T15:46:59.444Z","dateUpdated":"2026-10-19T09:24:33.989Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-25T10:25:14.366Z"},"containers":{"cna":{"title":"nvmet: copy the hostid into the ctrl before creating PR pc_refs","descriptions":[{"lang":"en","value":"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->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."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"7b658153f1b8a79ed98980f2fef7b92a66aeb9cd","status":"affected","lessThan":"d3d6d7efdacc08616d23b3ac42272a494951dc0f","versionType":"git"},{"version":"7b658153f1b8a79ed98980f2fef7b92a66aeb9cd","status":"affected","lessThan":"23194531595c5d1d4454e3a607b0c8fc0c4e8695","versionType":"git"},{"version":"7b658153f1b8a79ed98980f2fef7b92a66aeb9cd","status":"affected","lessThan":"5211fed41d7ec90e9ab7239dc4bffffe4d0b2b62","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/nvme/target/core.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.15","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.15","versionType":"semver"},{"version":"6.18.56","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.10","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/nvme/target/core.c"]}],"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"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-19T09:24:33.989Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.15","versionEndExcluding":"6.18.56"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.15","versionEndExcluding":"7.2.10"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.15","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}