{"api_version":"1","generated_at":"2026-08-23T09:26:23+00:00","cve":"CVE-2026-68148","urls":{"html":"https://cve.report/CVE-2026-68148","api":"https://cve.report/api/cve/CVE-2026-68148.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-68148","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-68148"},"summary":{"title":"fscrypt: Add missing superblock check in find_or_insert_direct_key()","description":"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 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.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-08-10 13:20:00","updated_at":"2026-08-19 17:20:32"},"problem_types":[],"metrics":[{"version":"3.1","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","score":"7.8","severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"}},{"version":"3.1","source":"CNA","type":"DECLARED","score":"7.8","severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","data":{"baseScore":7.8,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"}}],"references":[{"url":"https://git.kernel.org/stable/c/965b5bc8cf5031225e057979ce660fec2bd5fbfc","name":"https://git.kernel.org/stable/c/965b5bc8cf5031225e057979ce660fec2bd5fbfc","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/330249609b70778094a7a36f5b6bcfa6362121d4","name":"https://git.kernel.org/stable/c/330249609b70778094a7a36f5b6bcfa6362121d4","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/b5fa40226e71c17847b9ff2816c6ca4133d0d994","name":"https://git.kernel.org/stable/c/b5fa40226e71c17847b9ff2816c6ca4133d0d994","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/466f187b501a5ac8e1ea2ccf3ccd5c46108d8830","name":"https://git.kernel.org/stable/c/466f187b501a5ac8e1ea2ccf3ccd5c46108d8830","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/95376fe9c145be35566991df99c53134943d992f","name":"https://git.kernel.org/stable/c/95376fe9c145be35566991df99c53134943d992f","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/deff41898a5ae3a47db5fa1896a494aa95efda5d","name":"https://git.kernel.org/stable/c/deff41898a5ae3a47db5fa1896a494aa95efda5d","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-68148","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-68148","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 22e9947a4b2ba255888541bd0111cf00b9b16586 965b5bc8cf5031225e057979ce660fec2bd5fbfc git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 22e9947a4b2ba255888541bd0111cf00b9b16586 330249609b70778094a7a36f5b6bcfa6362121d4 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 22e9947a4b2ba255888541bd0111cf00b9b16586 deff41898a5ae3a47db5fa1896a494aa95efda5d git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 22e9947a4b2ba255888541bd0111cf00b9b16586 95376fe9c145be35566991df99c53134943d992f git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 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7.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"68148","cve":"CVE-2026-68148","epss":"0.000910000","percentile":"0.005620000","score_date":"2026-08-19","updated_at":"2026-08-20 00:13:09"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["fs/crypto/keysetup_v1.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"965b5bc8cf5031225e057979ce660fec2bd5fbfc","status":"affected","version":"22e9947a4b2ba255888541bd0111cf00b9b16586","versionType":"git"},{"lessThan":"330249609b70778094a7a36f5b6bcfa6362121d4","status":"affected","version":"22e9947a4b2ba255888541bd0111cf00b9b16586","versionType":"git"},{"lessThan":"deff41898a5ae3a47db5fa1896a494aa95efda5d","status":"affected","version":"22e9947a4b2ba255888541bd0111cf00b9b16586","versionType":"git"},{"lessThan":"95376fe9c145be35566991df99c53134943d992f","status":"affected","version":"22e9947a4b2ba255888541bd0111cf00b9b16586","versionType":"git"},{"lessThan":"466f187b501a5ac8e1ea2ccf3ccd5c46108d8830","status":"affected","version":"22e9947a4b2ba255888541bd0111cf00b9b16586","versionType":"git"},{"lessThan":"b5fa40226e71c17847b9ff2816c6ca4133d0d994","status":"affected","version":"22e9947a4b2ba255888541bd0111cf00b9b16586","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["fs/crypto/keysetup_v1.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"6.1"},{"lessThan":"6.1","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.1.*","status":"unaffected","version":"6.1.183","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.148","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.101","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.42","versionType":"semver"},{"lessThanOrEqual":"7.1.*","status":"unaffected","version":"7.1.6","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.2","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.1.183","versionStartIncluding":"6.1","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.148","versionStartIncluding":"6.1","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.101","versionStartIncluding":"6.1","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.42","versionStartIncluding":"6.1","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.1.6","versionStartIncluding":"6.1","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2","versionStartIncluding":"6.1","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"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 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."}],"metrics":[{"cvssV3_1":{"baseScore":7.8,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},"scenarios":[{"lang":"en","value":"AV:L - The flaw is reached only through local syscalls (mount/umount, FS_IOC_SET_ENCRYPTION_POLICY, and file I/O that calls fscrypt_get_encryption_info -> find_or_insert_direct_key); fscrypt is not invoked from network-facing kernel services.\nAC:L - An attacker who can mount two encrypted filesystems with the same v1 DIRECT_KEY master key, share the global cache entry, then unmount the first superblock can deterministically trigger eviction-time cleanup on a freed super_block without races or victim-dependent timing.\nPR:L - Exploitation requires mounting/unmounting filesystems and setting v1 DIRECT_KEY policies (CAP_SYS_ADMIN in a user/mount namespace) or supplying keys via process keyrings; per kernel guidance, CAP_SYS_ADMIN obtainable in user namespaces maps to PR:L.\nUI:N - No separate victim action is required; the attacker sets v1 DIRECT_KEY policies, accesses encrypted inodes on two mounts, and controls unmount/eviction to hit the vulnerable refcount and cleanup path.\nS:U - The use-after-free corrupts kernel heap memory and enables local privilege escalation within the same kernel; it does not cross VM, hypervisor, or IOMMU security boundaries.\nC:H - Extending a fscrypt_direct_key past its super_block lifetime causes cleanup to dereference a freed super_block in fscrypt_destroy_inline_crypt_key(), a use-after-free that can leak kernel memory and support arbitrary-read exploitation primitives.\nI:H - Use-after-free during inline-crypto key destruction on a dangling super_block pointer can be leveraged for heap corruption and arbitrary kernel writes, enabling local privilege escalation rather than only a controlled crash.\nA:H - Evicting the last inode holding the mismatched fscrypt_direct_key dereferences a freed super_block during key teardown, which can cause kernel oops/panic and complete local denial of service on encrypted mobile/embedded and server systems using inline encryption."}]}],"providerMetadata":{"dateUpdated":"2026-08-19T16:30:13.417Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"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"}],"title":"fscrypt: Add missing superblock check in find_or_insert_direct_key()","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-68148","datePublished":"2026-08-10T11:59:13.413Z","dateReserved":"2026-07-30T09:28:09.371Z","dateUpdated":"2026-08-19T16:30:13.417Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-08-10 13:20:00","lastModifiedDate":"2026-08-19 17:20:32","problem_types":[],"metrics":{"cvssMetricV31":[{"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"},"exploitabilityScore":1.8,"impactScore":5.9}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"68148","Ordinal":"1","Title":"fscrypt: Add missing superblock check in find_or_insert_direct_k","CVE":"CVE-2026-68148","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"68148","Ordinal":"1","NoteData":"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 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.","Type":"Description","Title":"fscrypt: Add missing superblock check in find_or_insert_direct_k"}]}}}