CVE-2026-90206

Unknown

Last modified

CVE-2026-90206 is a vulnerability of currently unknown severity. In the Linux kernel, the following vulnerability has been resolved: nvmet: fix max_qid race between configfs and controller allocation The function nvmet_subsys_attr_qid_max_store() can race against nvmet_alloc_ctrl() when a subsystem's max_qid limit is modified. Suppose max_qid is currently 64. If nvmet_alloc_ctrl() executes: ctrl->sqs = kzalloc_objs(struct nvmet_sq *, subsys->max_qid + 1); and at this exact point, a userspace process changes max_qid to 128, nvmet_subsys_attr_qid_max_store() will set the new max_qid value.

Description

In the Linux kernel, the following vulnerability has been resolved: nvmet: fix max_qid race between configfs and controller allocation The function nvmet_subsys_attr_qid_max_store() can race against nvmet_alloc_ctrl() when a subsystem's max_qid limit is modified. Suppose max_qid is currently 64. If nvmet_alloc_ctrl() executes: ctrl->sqs = kzalloc_objs(struct nvmet_sq *, subsys->max_qid + 1); and at this exact point, a userspace process changes max_qid to 128, nvmet_subsys_attr_qid_max_store() will set the new max_qid value. It attempts to delete active controllers to force a reconnect, but the new controller won't be deleted because it hasn't been added to the subsys->ctrls list yet. nvmet_alloc_ctrl() then proceeds and adds the new controller to the subsys->ctrls list. Later, when nvmet_install_queue() is called, it will see max_qid set to 128, but the memory allocated for sqs is only sized for 64 entries. This results in a KASAN out-of-bounds warning and potential memory corruptions. Fix this by protecting the queue allocations and list insertion in nvmet_alloc_ctrl() with down_read(&nvmet_config_sem). Because nvmet_subsys_attr_qid_max_store() acquires down_write(&nvmet_config_sem) to modify the attribute, this safely prevents the configfs writer from modifying max_qid during controller creation. Copy the max_qid from the subsystem to the controller's structure during the allocation; ctrl->max_qid never changes as long as the controller remains in LIVE state, so this will prevent similar race conditions.

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
LinuxLinux>= 3e980f5995e0bb4d86fef873a9c9ad66721580d0, < 2c23fc91789dfd9db746edb3ae9b90d65fabd410; >= 3e980f5995e0bb4d86fef873a9c9ad66721580d0, < f1a8846e06388113dfdbb89dee005083fa9afdf9
LinuxLinux6.1

References

Timeline

Published
Last Modified
Status
Received

Frequently Asked Questions

What is CVE-2026-90206?
In the Linux kernel, the following vulnerability has been resolved: nvmet: fix max_qid race between configfs and controller allocation The function nvmet_subsys_attr_qid_max_store() can race against nvmet_alloc_ctrl() when a subsystem's max_qid limit is modified. Suppose max_qid is currently 64. If nvmet_alloc_ctrl() executes: ctrl->sqs = kzalloc_objs(struct nvmet_sq *, subsys->max_qid + 1); and at this exact point, a userspace process changes max_qid to 128, nvmet_subsys_attr_qid_max_store() will set the new max_qid value. It attempts to delete active controllers to force a reconnect, but the new controller won't be deleted because it hasn't been added to the subsys->ctrls list yet. nvmet_alloc_ctrl() then proceeds and adds the new controller to the subsys->ctrls list. Later, when nvmet_install_queue() is called, it will see max_qid set to 128, but the memory allocated for sqs is only sized for 64 entries. This results in a KASAN out-of-bounds warning and potential memory corruptions. Fix this by protecting the queue allocations and list insertion in nvmet_alloc_ctrl() with down_read(&nvmet_config_sem). Because nvmet_subsys_attr_qid_max_store() acquires down_write(&nvmet_config_sem) to modify the attribute, this safely prevents the configfs writer from modifying max_qid during controller creation. Copy the max_qid from the subsystem to the controller's structure during the allocation; ctrl->max_qid never changes as long as the controller remains in LIVE state, so this will prevent similar race conditions.
How severe is CVE-2026-90206?
Severity scoring for CVE-2026-90206 is pending analysis.
How do I fix CVE-2026-90206?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST