{"id":"CVE-2022-50086","state":"PUBLISHED","title":"block: don't allow the same type rq_qos add more than once","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.","publishedAt":"2025-06-18T11:02:27.283Z","updatedAt":"2026-05-11T19:12:33.587Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"a79050434b45959f397042080fd1d70ffa9bd9df","status":"affected","lessThan":"0b7f5d7a4d2a72ad9de04ab8ccba2a31904aa638","versionType":"git"},{"version":"a79050434b45959f397042080fd1d70ffa9bd9df","status":"affected","lessThan":"08ef66e800a85afc6b54cb95841f6502627eee2e","versionType":"git"},{"version":"a79050434b45959f397042080fd1d70ffa9bd9df","status":"affected","lessThan":"0c9bb1acd1d103a3070b2126870eb52761d606ce","versionType":"git"},{"version":"a79050434b45959f397042080fd1d70ffa9bd9df","status":"affected","lessThan":"14a6e2eb7df5c7897c15b109cba29ab0c4a791b6","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["block/blk-iocost.c","block/blk-iolatency.c","block/blk-rq-qos.h","block/blk-wbt.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.19","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.19","versionType":"semver"},{"version":"5.15.61","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"5.18.18","status":"unaffected","lessThanOrEqual":"5.18.*","versionType":"semver"},{"version":"5.19.2","status":"unaffected","lessThanOrEqual":"5.19.*","versionType":"semver"},{"version":"6.0","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["block/blk-iocost.c","block/blk-iolatency.c","block/blk-rq-qos.h","block/blk-wbt.c"]}],"references":["https://git.kernel.org/stable/c/0b7f5d7a4d2a72ad9de04ab8ccba2a31904aa638","https://git.kernel.org/stable/c/08ef66e800a85afc6b54cb95841f6502627eee2e","https://git.kernel.org/stable/c/0c9bb1acd1d103a3070b2126870eb52761d606ce","https://git.kernel.org/stable/c/14a6e2eb7df5c7897c15b109cba29ab0c4a791b6"],"weaknesses":[],"ingestedAt":"2026-10-29T20:05:26.763Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2022/50xxx/CVE-2022-50086.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2022-50086","state":"PUBLISHED","datePublished":"2025-06-18T11:02:27.283Z","dateUpdated":"2026-05-11T19:12:33.587Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2025-06-18T10:57:27.410Z"},"containers":{"cna":{"title":"block: don't allow the same type rq_qos add more than once","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"a79050434b45959f397042080fd1d70ffa9bd9df","status":"affected","lessThan":"0b7f5d7a4d2a72ad9de04ab8ccba2a31904aa638","versionType":"git"},{"version":"a79050434b45959f397042080fd1d70ffa9bd9df","status":"affected","lessThan":"08ef66e800a85afc6b54cb95841f6502627eee2e","versionType":"git"},{"version":"a79050434b45959f397042080fd1d70ffa9bd9df","status":"affected","lessThan":"0c9bb1acd1d103a3070b2126870eb52761d606ce","versionType":"git"},{"version":"a79050434b45959f397042080fd1d70ffa9bd9df","status":"affected","lessThan":"14a6e2eb7df5c7897c15b109cba29ab0c4a791b6","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["block/blk-iocost.c","block/blk-iolatency.c","block/blk-rq-qos.h","block/blk-wbt.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.19","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.19","versionType":"semver"},{"version":"5.15.61","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"5.18.18","status":"unaffected","lessThanOrEqual":"5.18.*","versionType":"semver"},{"version":"5.19.2","status":"unaffected","lessThanOrEqual":"5.19.*","versionType":"semver"},{"version":"6.0","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["block/blk-iocost.c","block/blk-iolatency.c","block/blk-rq-qos.h","block/blk-wbt.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/0b7f5d7a4d2a72ad9de04ab8ccba2a31904aa638"},{"url":"https://git.kernel.org/stable/c/08ef66e800a85afc6b54cb95841f6502627eee2e"},{"url":"https://git.kernel.org/stable/c/0c9bb1acd1d103a3070b2126870eb52761d606ce"},{"url":"https://git.kernel.org/stable/c/14a6e2eb7df5c7897c15b109cba29ab0c4a791b6"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-05-11T19:12:33.587Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.19","versionEndExcluding":"5.15.61"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.19","versionEndExcluding":"5.18.18"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.19","versionEndExcluding":"5.19.2"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.19","versionEndExcluding":"6.0"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}