{"cve":"CVE-2026-90206","nvd":{"published":"2026-09-17T17:17:15.700","modified":"2026-10-21T13:20:43.207","status":"Received","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnvmet: fix max_qid race between configfs and controller allocation\n\nThe function nvmet_subsys_attr_qid_max_store() can race against\nnvmet_alloc_ctrl() when a subsystem's max_qid limit is modified.\n\nSuppose max_qid is currently 64. If nvmet_alloc_ctrl() executes:\nctrl->sqs = kzalloc_objs(struct nvmet_sq *, subsys->max_qid + 1);\nand at this exact point, a userspace process changes max_qid to 128,\nnvmet_subsys_attr_qid_max_store() will set the new max_qid value. It\nattempts to delete active controllers to force a reconnect, but the\nnew controller won't be deleted because it hasn't been added to the\nsubsys->ctrls list yet.\n\nnvmet_alloc_ctrl() then proceeds and adds the new controller to the\nsubsys->ctrls list. Later, when nvmet_install_queue() is called, it\nwill see max_qid set to 128, but the memory allocated for sqs is only\nsized for 64 entries. This results in a KASAN out-of-bounds warning\nand potential memory corruptions.\n\nFix this by protecting the queue allocations and list insertion in\nnvmet_alloc_ctrl() with down_read(&nvmet_config_sem). Because\nnvmet_subsys_attr_qid_max_store() acquires down_write(&nvmet_config_sem)\nto modify the attribute, this safely prevents the configfs writer from\nmodifying max_qid during controller creation.\n\nCopy the max_qid from the subsystem to the controller's structure\nduring the allocation; ctrl->max_qid never changes as long as the\ncontroller remains in LIVE state, so this will prevent similar race\nconditions.","cvss_v4":null,"cvss_v3":null,"cwes":[],"references":["https://git.kernel.org/stable/c/2c23fc91789dfd9db746edb3ae9b90d65fabd410","https://git.kernel.org/stable/c/6e6f8e3bfc66dff1833a48ecfd857268cff3be84","https://git.kernel.org/stable/c/a1b88a1782eb6b368071dcda548a41b5c23d8cd2","https://git.kernel.org/stable/c/af811970da4f0a928f5a1b1a946a04f755ce86f2","https://git.kernel.org/stable/c/f1a8846e06388113dfdbb89dee005083fa9afdf9"],"products":[],"source":"nvd","synced_at":"2026-10-22T16:41:11.231219466+00:00"},"epss":{"cve":"CVE-2026-90206","score":0.00209,"percentile":0.10951,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}