{"id":"CVE-2022-50630","title":"mm: hugetlb: fix UAF in hugetlb_handle_userfault","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nmm: hugetlb: fix UAF in hugetlb_handle_userfault\n\nThe vma_lock and hugetlb_fault_mutex are dropped before handling userfault\nand reacquire them again after handle_userf…","severity":"high","cvss":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= 1a1aad8a9b7bd34f60cdf98cd7915f00ae892c45 < 45c33966759ea1b4040c08dacda99ef623c0ca29","Linux >= 1a1aad8a9b7bd34f60cdf98cd7915f00ae892c45 < 0db2efb3bff879566f05341d94c3de00ac95c4cc","Linux >= 1a1aad8a9b7bd34f60cdf98cd7915f00ae892c45 < dd691973f67b2800a97db723b1ff6f07fdcf7f5a","Linux >= 1a1aad8a9b7bd34f60cdf98cd7915f00ae892c45 < 78504bcedb2f1bbfb353b4d233c24d641c4dda33","Linux >= 1a1aad8a9b7bd34f60cdf98cd7915f00ae892c45 < 958f32ce832ba781ac20e11bb2d12a9352ea28fc","Linux 4.11"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-10-15T21:31:42.914433Z"},"published":"2025-12-08","updated":"2026-10-15","sourceUpdated":"2026-10-15T21:41:21.996Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2022-50630","references":[{"url":"https://git.kernel.org/stable/c/45c33966759ea1b4040c08dacda99ef623c0ca29"},{"url":"https://git.kernel.org/stable/c/0db2efb3bff879566f05341d94c3de00ac95c4cc"},{"url":"https://git.kernel.org/stable/c/dd691973f67b2800a97db723b1ff6f07fdcf7f5a"},{"url":"https://git.kernel.org/stable/c/78504bcedb2f1bbfb353b4d233c24d641c4dda33"},{"url":"https://git.kernel.org/stable/c/958f32ce832ba781ac20e11bb2d12a9352ea28fc"}],"tags":["cve.org"],"epss":0.00153,"epssPercentile":0.03976,"ingestedAt":"2026-10-15T22:48:25.377Z","slug":"CVE-2022-50630","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nmm: hugetlb: fix UAF in hugetlb_handle_userfault\n\nThe vma_lock and hugetlb_fault_mutex are dropped before handling userfault\nand reacquire them again after handle_userfault(), but reacquire the\nvma_lock could lead to UAF[1,2] due to the following race,\n\nhugetlb_fault\n  hugetlb_no_page\n    /*unlock vma_lock */\n    hugetlb_handle_userfault\n      handle_userfault\n        /* unlock mm->mmap_lock*/\n                                           vm_mmap_pgoff\n                                             do_mmap\n                                               mmap_region\n                                                 munmap_vma_range\n                                                   /* clean old vma */\n        /* lock vma_lock again  <--- UAF */\n    /* unlock vma_lock */\n\nSince the vma_lock will unlock immediately after\nhugetlb_handle_userfault(), let's drop the unneeded lock and unlock in\nhugetlb_handle_userfault() to fix the issue.\n\n[1] https://lore.kernel.org/linux-mm/000000000000d5e00a05e834962e@google.com/\n[2] https://lore.kernel.org/linux-mm/20220921014457.1668-1-liuzixian4@huawei.com/\n\n## Affected\n\n- `Linux >= 1a1aad8a9b7bd34f60cdf98cd7915f00ae892c45 < 45c33966759ea1b4040c08dacda99ef623c0ca29`\n- `Linux >= 1a1aad8a9b7bd34f60cdf98cd7915f00ae892c45 < 0db2efb3bff879566f05341d94c3de00ac95c4cc`\n- `Linux >= 1a1aad8a9b7bd34f60cdf98cd7915f00ae892c45 < dd691973f67b2800a97db723b1ff6f07fdcf7f5a`\n- `Linux >= 1a1aad8a9b7bd34f60cdf98cd7915f00ae892c45 < 78504bcedb2f1bbfb353b4d233c24d641c4dda33`\n- `Linux >= 1a1aad8a9b7bd34f60cdf98cd7915f00ae892c45 < 958f32ce832ba781ac20e11bb2d12a9352ea28fc`\n- `Linux 4.11`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":43,"depthScoreParts":{"impact":42.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}