Vulnerabilities

Vulnerability · 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_q…

Published Sep 17, 2026 · catalog updated Oct 15, 2026 · the affected product

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No confirmed exploitation is on record for CVE-2026-90206. EPSS is 0.21%. Act only if a listed version of the affected product is installed.

Severity

Unknown—

Known exploitation

Not in CISA/VulnCheck KEV

EPSS

0.21%

Remediation

Not established

Affected products

See sources for product scope

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.

No affected version ranges are stored yet. Use the vendor advisory before you decide this record does not apply.