{"cve":"CVE-2022-50086","nvd":{"published":"2025-06-18T11:15:37.690","modified":"2026-06-17T05:22:43.760","status":"Analyzed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nblock: don't allow the same type rq_qos add more than once\n\nIn our test of iocost, we encountered some list add/del corruptions of\ninner_walk list in ioc_timer_fn.\n\nThe reason can be described as follows:\n\ncpu 0\t\t\t\t\tcpu 1\nioc_qos_write\t\t\t\tioc_qos_write\n\nioc = q_to_ioc(queue);\nif (!ioc) {\n        ioc = kzalloc();\n\t\t\t\t\tioc = q_to_ioc(queue);\n\t\t\t\t\tif (!ioc) {\n\t\t\t\t\t\tioc = kzalloc();\n\t\t\t\t\t\t...\n\t\t\t\t\t\trq_qos_add(q, rqos);\n\t\t\t\t\t}\n        ...\n        rq_qos_add(q, rqos);\n        ...\n}\n\nWhen the io.cost.qos file is written by two cpus concurrently, rq_qos may\nbe added to one disk twice. In that case, there will be two iocs enabled\nand running on one disk. They own different iocgs on their active list. In\nthe ioc_timer_fn function, because of the iocgs from two iocs have the\nsame root iocg, the root iocg's walk_list may be overwritten by each other\nand this leads to list add/del corruptions in building or destroying the\ninner_walk list.\n\nAnd so far, the blk-rq-qos framework works in case that one instance for\none type rq_qos per queue by default. This patch make this explicit and\nalso fix the crash above.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":[],"references":["https://git.kernel.org/stable/c/08ef66e800a85afc6b54cb95841f6502627eee2e","https://git.kernel.org/stable/c/0b7f5d7a4d2a72ad9de04ab8ccba2a31904aa638","https://git.kernel.org/stable/c/0c9bb1acd1d103a3070b2126870eb52761d606ce","https://git.kernel.org/stable/c/14a6e2eb7df5c7897c15b109cba29ab0c4a791b6"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:03:23.287444849+00:00"},"epss":{"cve":"CVE-2022-50086","score":0.00193,"percentile":0.09013,"date":"2026-10-31"},"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."]}