Bug 2555091 (CVE-2026-98723)
| Summary: | CVE-2026-98723 kernel: nvmet: copy the hostid into the ctrl before creating PR pc_refs | ||
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| Product: | [Other] Security Response | Reporter: | OSIDB Bzimport <bzimport> |
| Component: | vulnerability | Assignee: | Product Security DevOps Team <prodsec-dev> |
| Status: | NEW --- | QA Contact: | |
| Severity: | medium | Docs Contact: | |
| Priority: | medium | ||
| Version: | unspecified | CC: | akhatavk, aos-team-art-private, asdas, dpaolell, jdelft, jupierce, lgarciaa, mbiarnes, ppalepu, ppostler, prdhamdh, rhel-process-autobot, sghai, sidsharm, suppawar, vlaad, watson-tool-maintainers |
| Target Milestone: | --- | Keywords: | Security |
| Target Release: | --- | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | --- | |
| Doc Text: |
A flaw was found in the Linux kernel's NVMe target (nvmet) subsystem. An uninitialized host identifier in persistent reservation references prevents the target from aborting and draining in-flight input/output (I/O) requests during a Preempt and Abort operation. A connected NVMe host can trigger this condition when preempting a reservation, allowing conflicting operations from the prior host to continue and potentially leading to data corruption.
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Story Points: | --- |
| Clone Of: | Environment: | ||
| Last Closed: | Type: | --- | |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
In the Linux kernel, the following vulnerability has been resolved: nvmet: copy the hostid into the ctrl before creating PR pc_refs Commit 6202783184bf ("nvmet: Improve nvmet_alloc_ctrl() interface and implementation") added a second uuid_copy() of args->hostid near the end of nvmet_alloc_ctrl(), and commit 7b658153f1b8 ("nvmet: Remove duplicate uuid_copy") removed the original copy that sat before nvmet_ctrl_init_pr() instead of the new one. Since then nvmet_ctrl_init_pr() snapshots ctrl->hostid into the per-controller per-namespace reservation refs while the uuid_copy() from the connect data runs later, after the controller is published. The ctrl is allocated with kzalloc(), so every pc_ref created on this path stores the nil UUID. pc_ref->hostid has a single consumer: nvmet_pr_set_ctrl_to_abort() matches it against the preempted registrant's hostid to kill and drain the victim's in-flight I/O for Preempt and Abort. The match can never hit with the nil UUID, so whenever a namespace with reservations enabled exists before a host connects, which includes every reconnect, Preempt and Abort silently degrades into a plain Preempt: the preempting host sees success while the victim's in-flight I/O is still in the air. Copy the hostid where the rest of the connect data is consumed, before the controller is published and before nvmet_ctrl_init_pr() takes its snapshot.