{"id":"CVE-2026-90206","title":"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'…","summary":"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'…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 3e980f5995e0bb4d86fef873a9c9ad66721580d0 < 2c23fc91789dfd9db746edb3ae9b90d65fabd410","Linux >= 3e980f5995e0bb4d86fef873a9c9ad66721580d0 < f1a8846e06388113dfdbb89dee005083fa9afdf9","Linux 6.1"],"published":"2026-09-17","updated":"2026-09-17","sourceUpdated":"2026-09-17T17:17:15.700","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-90206","references":[{"url":"https://git.kernel.org/stable/c/2c23fc91789dfd9db746edb3ae9b90d65fabd410","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/f1a8846e06388113dfdbb89dee005083fa9afdf9","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd","cve.org"],"ingestedAt":"2026-09-17T16:21:47.859Z","epss":0.00189,"epssPercentile":0.08809,"slug":"CVE-2026-90206","body":"## Overview\n\nIn 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}