{"id":"CVE-2026-68148","title":"fscrypt: Add missing superblock check in find_or_insert_direct_key()","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nfscrypt: Add missing superblock check in find_or_insert_direct_key()\n\nThe legacy 'fscrypt_direct_keys' table caches master keys that are used\nby v1 encryption policies …","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","cwe":["CWE-772"],"vendor":"Linux","product":"Linux","affected":["Linux >= 22e9947a4b2ba255888541bd0111cf00b9b16586 < 965b5bc8cf5031225e057979ce660fec2bd5fbfc","Linux >= 22e9947a4b2ba255888541bd0111cf00b9b16586 < 330249609b70778094a7a36f5b6bcfa6362121d4","Linux >= 22e9947a4b2ba255888541bd0111cf00b9b16586 < deff41898a5ae3a47db5fa1896a494aa95efda5d","Linux >= 22e9947a4b2ba255888541bd0111cf00b9b16586 < 95376fe9c145be35566991df99c53134943d992f","Linux >= 22e9947a4b2ba255888541bd0111cf00b9b16586 < 466f187b501a5ac8e1ea2ccf3ccd5c46108d8830","Linux >= 22e9947a4b2ba255888541bd0111cf00b9b16586 < b5fa40226e71c17847b9ff2816c6ca4133d0d994","Linux 6.1"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-10-16T15:44:51.705940Z"},"published":"2026-08-10","updated":"2026-10-19","sourceUpdated":"2026-10-19T20:58:54.031Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-68148","references":[{"url":"https://git.kernel.org/stable/c/965b5bc8cf5031225e057979ce660fec2bd5fbfc"},{"url":"https://git.kernel.org/stable/c/330249609b70778094a7a36f5b6bcfa6362121d4"},{"url":"https://git.kernel.org/stable/c/deff41898a5ae3a47db5fa1896a494aa95efda5d"},{"url":"https://git.kernel.org/stable/c/95376fe9c145be35566991df99c53134943d992f"},{"url":"https://git.kernel.org/stable/c/466f187b501a5ac8e1ea2ccf3ccd5c46108d8830"},{"url":"https://git.kernel.org/stable/c/b5fa40226e71c17847b9ff2816c6ca4133d0d994"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-68148.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-68148"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2513211"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-68148"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-68148"},{"url":"https://lore.kernel.org/linux-cve-announce/2026081001-CVE-2026-68148-7d8c@gregkh/T"}],"tags":["cve.org","csaf","vex","red-hat"],"epss":0.00092,"epssPercentile":0.00475,"scores":{"cna":7.8,"vendor":7},"ingestedAt":"2026-10-16T17:24:46.845Z","slug":"CVE-2026-68148","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nfscrypt: Add missing superblock check in find_or_insert_direct_key()\n\nThe legacy 'fscrypt_direct_keys' table caches master keys that are used\nby v1 encryption policies that have FSCRYPT_POLICY_FLAG_DIRECT_KEY.\nIt's just a global table for all filesystems (since the keys can be\nprovided by the legacy process-subscribed keyrings mechanism, which\nmakes it difficult to reuse super_block::s_master_keys).\n\nThe entries in it ('struct fscrypt_direct_key') do contain a super_block\npointer, though, for passing to fscrypt_destroy_inline_crypt_key() when\nthe last inode that references the key is evicted.\n\nHowever, when finding the fscrypt_direct_key for an inode, we weren't\nactually comparing the super_block pointer.  As a result, inodes with\ndifferent super_blocks could point to the same fscrypt_direct_key.  That\ncould extend the lifetime of a fscrypt_direct_key beyond the\nsuper_block it points to, causing a use-after-free later.\n\nFix this by creating distinct fscrypt_direct_key structs for distinct\nsuper_block structs.\n\nNote that this problem doesn't exist in the v2 policy equivalent\n(\"per-mode keys\"), since the data structures there are per super_block.\n\n## Affected\n\n- `Linux >= 22e9947a4b2ba255888541bd0111cf00b9b16586 < 965b5bc8cf5031225e057979ce660fec2bd5fbfc`\n- `Linux >= 22e9947a4b2ba255888541bd0111cf00b9b16586 < 330249609b70778094a7a36f5b6bcfa6362121d4`\n- `Linux >= 22e9947a4b2ba255888541bd0111cf00b9b16586 < deff41898a5ae3a47db5fa1896a494aa95efda5d`\n- `Linux >= 22e9947a4b2ba255888541bd0111cf00b9b16586 < 95376fe9c145be35566991df99c53134943d992f`\n- `Linux >= 22e9947a4b2ba255888541bd0111cf00b9b16586 < 466f187b501a5ac8e1ea2ccf3ccd5c46108d8830`\n- `Linux >= 22e9947a4b2ba255888541bd0111cf00b9b16586 < b5fa40226e71c17847b9ff2816c6ca4133d0d994`\n- `Linux 6.1`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9 · updated 2026-10-16 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-68148.json)","depth":"twilight","depthScore":43,"depthScoreParts":{"impact":42.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":225248,"id":"CVE-2026-68148","ts":1792446346398,"field":"cvss","old":"7","new":"7.8"},{"seq":223656,"id":"CVE-2026-68148","ts":1792238350185,"field":"cvss","old":"7.8","new":"7"}]}