{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-93810", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-18T17:59:28.790Z", "datePublished": "2026-09-24T16:02:46.426Z", "dateUpdated": "2026-09-25T12:43:18.276Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-09-25T12:43:18.276Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncachefiles: Fix double fput\n\nFix a double fput() in error handling in cachefiles_create_tmpfile()."}], "metrics": [{"cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7, "baseSeverity": "HIGH"}, "scenarios": [{"lang": "en", "value": "AV:L - The extra fput is in cachefiles_create_tmpfile(), reached from nfs_fscache_open_file() (or CIFS/9p/AFS/Ceph fscache_use_cookie()) \u2192 fscache_perform_lookup() \u2192 cachefiles_lookup_cookie() \u2192 cachefiles_look_up_object() \u2192 cachefiles_create_file(), or from cachefiles_invalidate_cookie(); a local open/inval of an fscache-backed file is the entry, not a remote protocol message.\nAC:H - The double fput runs only when kernel_tmpfile_open()'s file has a NULL f_op->read_iter or f_op->write_iter. cachefiles_add_cache() requires tmpfile/xattr/sync_fs and s_blocksize<=PAGE_SIZE but never checks those f_ops; the only in-tree tmpfile FS lacking write_iter is hugetlbfs, which add_cache rejects, so an attacker cannot make a bound ext4/xfs/btrfs/f2fs tmpfile take this branch.\nPR:L - nfs_fscache_open_file() and the sibling fscache_use_cookie() open paths have no capable() check, so an unprivileged user with read access on an already-bound cachefiles/fscache mount drives cookie lookup into cachefiles_create_tmpfile(); cachefiles_daemon_open() needs init-namespace CAP_SYS_ADMIN, but that is not this trigger.\nUI:N - The attacker themselves open or invalidate files on the fscache-enabled netfs mount, which queues fscache_perform_lookup() into cachefiles_create_tmpfile(); no other user must mount the volume or issue cachefilesd commands.\nS:U - Double-putting the cache tmpfile's struct file corrupts host kernel file-refcount and filp_cachep state only; it does not cross a KVM/Xen, IOMMU, or other distinct authority.\nC:H - On the !read_iter/!write_iter branch, cachefiles_create_tmpfile() fput()s then err_unuse calls file_inode(file) and fput()s again. fscache_perform_lookup() runs in a PF_KTHREAD worker so the first put is deferred via delayed_fput_work; a later file_inode() on that pointer is a UAF read of a SLAB_TYPESAFE_BY_RCU struct file.\nI:H - The leftover fput before goto err_unuse is a struct-file double-put: if delayed __fput() has already file_free()'d the tmpfile, the second file_ref_put() writes a recycled filp_cachep object (or an underflowed live ref into the dead zone), a UAF write primitive against struct file.\nA:H - The second put hits __file_ref_put_badval()'s \"imbalanced put on file reference count\" WARN_ONCE, and if delayed_fput already ran, file_inode()/inode_lock/fput in cachefiles_create_tmpfile() err_unuse dereference freed memory and oops the fscache worker."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/cachefiles/namei.c"], "versions": [{"version": "24a81759b65fa85767739999d91523691c5e2ea5", "lessThan": "e9c2e68c3890a935abbd5f54dbce653f9a16836c", "status": "affected", "versionType": "git"}, {"version": "24a81759b65fa85767739999d91523691c5e2ea5", "lessThan": "90b306eee037d0a6a8f4aac834b46e05c5ddd0bf", "status": "affected", "versionType": "git"}, {"version": "24a81759b65fa85767739999d91523691c5e2ea5", "lessThan": "af6830cc12dfe86c832dccc9c9878a93aaa22f83", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/cachefiles/namei.c"], "versions": [{"version": "6.1", "status": "affected"}, {"version": "0", "lessThan": "6.1", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.111", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.53", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.2", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix"}]}], "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.1", "versionEndExcluding": "6.12.111"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.1", "versionEndExcluding": "6.18.53"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.1", "versionEndExcluding": "7.2"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/e9c2e68c3890a935abbd5f54dbce653f9a16836c"}, {"url": "https://git.kernel.org/stable/c/90b306eee037d0a6a8f4aac834b46e05c5ddd0bf"}, {"url": "https://git.kernel.org/stable/c/af6830cc12dfe86c832dccc9c9878a93aaa22f83"}], "title": "cachefiles: Fix double fput", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["fs/cachefiles/namei.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "e9c2e68c3890a935abbd5f54dbce653f9a16836c", "status": "affected", "version": "24a81759b65fa85767739999d91523691c5e2ea5", "versionType": "git"}, {"lessThan": "90b306eee037d0a6a8f4aac834b46e05c5ddd0bf", "status": "affected", "version": "24a81759b65fa85767739999d91523691c5e2ea5", "versionType": "git"}, {"lessThan": "af6830cc12dfe86c832dccc9c9878a93aaa22f83", "status": "affected", "version": "24a81759b65fa85767739999d91523691c5e2ea5", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["fs/cachefiles/namei.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": "6.12.*", "status": "unaffected", "version": "6.12.111", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.53", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.2", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncachefiles: Fix double fput\n\nFix a double fput() in error handling in cachefiles_create_tmpfile()."}], "id": "CVE-2026-93810", "lastModified": "2026-09-25T13:17:21.853", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "HIGH", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 7.0, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 1.0, "impactScore": 5.9, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}]}, "published": "2026-09-24T17:17:14.433", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/90b306eee037d0a6a8f4aac834b46e05c5ddd0bf"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/af6830cc12dfe86c832dccc9c9878a93aaa22f83"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/e9c2e68c3890a935abbd5f54dbce653f9a16836c"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[1da177e4c3f41524e886b7f1b8a0c1fc7321cac2,e9c2e68c3890a935abbd5f54dbce653f9a16836c)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[1da177e4c3f41524e886b7f1b8a0c1fc7321cac2,90b306eee037d0a6a8f4aac834b46e05c5ddd0bf)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[1da177e4c3f41524e886b7f1b8a0c1fc7321cac2,af6830cc12dfe86c832dccc9c9878a93aaa22f83)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[0,6.12.111)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[0,6.18.53)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.12.111,6.13.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.53,6.19.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.2,*]"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "created": "2026-09-24T23:00:14.431227+00:00", "updated": "2026-09-25T10:00:16.364988+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}