CVE-2026-99051

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-99051", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-25T10:25:14.388Z", "datePublished": "2026-10-23T12:22:30.370Z", "dateUpdated": "2026-10-24T14:10:12.469Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-24T14:10:12.469Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nfsverity: RCU-delay the freeing of struct fsverity_info\n\n__fsverity_get_info() calls rhashtable_lookup_fast(), which just uses\nrcu_read_lock() and doesn't directly synchronize with\nfsverity_remove_info().\n\nFor the same inode this isn't a problem: its fsverity_info is removed\nonly at inode eviction time or upon failure to enable verity, when the\ninode no longer needs its fsverity_info and it will no longer be\naccessed via that inode.\n\nHowever, this is broken and can cause a use-after-free for concurrent\n__fsverity_get_info() for *different* inodes. Those rely on following\nfsverity_info::rhash_head in the rhashtable under rcu_read_lock() only.\nThey also use fsverity_info::inode to do the key comparison.\n\nFix this by RCU-delaying the freeing of 'struct fsverity_info' after\nit's been removed from the rhashtable."}], "metrics": [{"cvssV3_1": {"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"}, "scenarios": [{"lang": "en", "value": "AV:L - `ioctl(FS_IOC_MEASURE_VERITY)` reaches `fsverity_ioctl_measure()` and `fsverity_get_info()`, while `unlinkat()`/`close()` of another fs-verity file reaches `clear_inode()`, `fsverity_cleanup_inode()`, and patched `fsverity_remove_info()`; these are local syscall paths, not wire data.\nAC:L - An attacker can enable many owned files to populate colliding rhashtable chains, then loop measurements of one inode while concurrently unlinking and closing the others; the attacker controls both lookup and freeing and can repeat the race.\nPR:L - `fsverity_ioctl_enable()` checks only `file_permission(filp, MAY_WRITE)`, `FMODE_READ`, and a writable mount, with no capability check; lookup and eviction require only ordinary access to attacker-owned files on btrfs or verity-enabled ext4/f2fs.\nUI:N - The attacker can create, enable, measure, unlink, and close all participating files using their own processes, without another user mounting media or taking any action.\nS:U - The dangling object belongs to the host kernel's `fsverity_info_hash` and `fsverity_info_cachep`; corrupting it affects the same kernel security authority and crosses no VM, IOMMU, or hypervisor boundary.\nC:H - `fsverity_remove_info()` frees the slab while `__rhashtable_lookup()` still reads `inode` and `rhash_head.next`; after cache reuse, a misdirected lookup is consumed by `fsverity_ioctl_measure()`, which dereferences `tree_params` and copies `file_digest` to userspace.\nI:H - File-read consumers pass the lookup result to `fsverity_verify_blocks()`, whose `clear_bit()` and `set_bit()` write through `vi->hash_block_verified`; attacker-groomed reuse of the freed object can therefore turn the UAF into arbitrary kernel-memory corruption.\nA:H - `kmem_cache_free()` permits allocator metadata to replace the freed `rhash_head.next` while the rhashtable loop still follows `pos->next`, which can oops or panic the kernel; repeated measure-and-evict cycles can retrigger it."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/verity/fsverity_private.h", "fs/verity/open.c"], "versions": [{"version": "f77f281b61183a5c0b87e6a4d101c70bd32c1c79", "lessThan": "fa84f091a8e7fc46fd29834496fab9739dd4c8dc", "status": "affected", "versionType": "git"}, {"version": "f77f281b61183a5c0b87e6a4d101c70bd32c1c79", "lessThan": "e58c3805ed325fe2d4ae2dd467c0486cc860b733", "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/verity/fsverity_private.h", "fs/verity/open.c"], "versions": [{"version": "7.0", "status": "affected"}, {"version": "0", "lessThan": "7.0", "status": "unaffected", "versionType": "semver"}, {"version": "7.2.11", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.3", "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": "7.0", "versionEndExcluding": "7.2.11"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "7.0", "versionEndExcluding": "7.3"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/fa84f091a8e7fc46fd29834496fab9739dd4c8dc"}, {"url": "https://git.kernel.org/stable/c/e58c3805ed325fe2d4ae2dd467c0486cc860b733"}], "title": "fsverity: RCU-delay the freeing of struct fsverity_info", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["fs/verity/fsverity_private.h", "fs/verity/open.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "fa84f091a8e7fc46fd29834496fab9739dd4c8dc", "status": "affected", "version": "f77f281b61183a5c0b87e6a4d101c70bd32c1c79", "versionType": "git"}, {"lessThan": "e58c3805ed325fe2d4ae2dd467c0486cc860b733", "status": "affected", "version": "f77f281b61183a5c0b87e6a4d101c70bd32c1c79", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["fs/verity/fsverity_private.h", "fs/verity/open.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "7.0"}, {"lessThan": "7.0", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "7.2.*", "status": "unaffected", "version": "7.2.11", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.3", "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\nfsverity: RCU-delay the freeing of struct fsverity_info\n\n__fsverity_get_info() calls rhashtable_lookup_fast(), which just uses\nrcu_read_lock() and doesn't directly synchronize with\nfsverity_remove_info().\n\nFor the same inode this isn't a problem: its fsverity_info is removed\nonly at inode eviction time or upon failure to enable verity, when the\ninode no longer needs its fsverity_info and it will no longer be\naccessed via that inode.\n\nHowever, this is broken and can cause a use-after-free for concurrent\n__fsverity_get_info() for *different* inodes. Those rely on following\nfsverity_info::rhash_head in the rhashtable under rcu_read_lock() only.\nThey also use fsverity_info::inode to do the key comparison.\n\nFix this by RCU-delaying the freeing of 'struct fsverity_info' after\nit's been removed from the rhashtable."}], "id": "CVE-2026-99051", "lastModified": "2026-10-24T14:16:53.773", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 7.8, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 5.9, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}]}, "published": "2026-10-23T13:17:28.633", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/e58c3805ed325fe2d4ae2dd467c0486cc860b733"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/fa84f091a8e7fc46fd29834496fab9739dd4c8dc"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: fsverity: RCU-delay the freeing of struct fsverity_info", "id": "2559731", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2559731"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.5", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-825", "details": ["In the Linux kernel, the following vulnerability has been resolved:\nfsverity: RCU-delay the freeing of struct fsverity_info\n__fsverity_get_info() calls rhashtable_lookup_fast(), which just uses\nrcu_read_lock() and doesn't directly synchronize with\nfsverity_remove_info().\nFor the same inode this isn't a problem: its fsverity_info is removed\nonly at inode eviction time or upon failure to enable verity, when the\ninode no longer needs its fsverity_info and it will no longer be\naccessed via that inode.\nHowever, this is broken and can cause a use-after-free for concurrent\n__fsverity_get_info() for *different* inodes. Those rely on following\nfsverity_info::rhash_head in the rhashtable under rcu_read_lock() only.\nThey also use fsverity_info::inode to do the key comparison.\nFix this by RCU-delaying the freeing of 'struct fsverity_info' after\nit's been removed from the rhashtable.", "A flaw was found in the Linux kernel's fsverity subsystem. A lack of proper synchronization when removing file verification structures allows concurrent lookup operations to access memory after it has been freed. A local user could exploit this vulnerability by triggering simultaneous file operations to cause a system crash, resulting in a denial of service (DoS), or potentially execute arbitrary code."], "name": "CVE-2026-99051", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/a:redhat:openshift:4", "fix_state": "Not affected", "package_name": "openshift/ose-rhel-coreos-8", "product_name": "Red Hat OpenShift Container Platform 4"}, {"cpe": "cpe:/a:redhat:openshift:4", "fix_state": "Not affected", "package_name": "openshift/ose-rhel-coreos-9", "product_name": "Red Hat OpenShift Container Platform 4"}], "public_date": "2026-10-23T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-99051\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-99051\nhttps://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-99051.mbox"], "threat_severity": "Moderate"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[f77f281b61183a5c0b87e6a4d101c70bd32c1c79,fa84f091a8e7fc46fd29834496fab9739dd4c8dc)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[f77f281b61183a5c0b87e6a4d101c70bd32c1c79,e58c3805ed325fe2d4ae2dd467c0486cc860b733)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "7.0"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[0,7.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.2.11,7.3.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.3,*]"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[f77f281b61183a5c0b87e6a4d101c70bd32c1c79,fa84f091a8e7fc46fd29834496fab9739dd4c8dc)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[f77f281b61183a5c0b87e6a4d101c70bd32c1c79,e58c3805ed325fe2d4ae2dd467c0486cc860b733)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "7.0"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[0,7.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.2.11,7.3.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.3,*]"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "created": "2026-10-23T16:00:18.684440+00:00", "updated": "2026-10-27T14:00:05.449641+00:00", "vendors": ["linux", "linux$PRODUCT$linux", "linux$PRODUCT$linux_kernel"], "weaknesses": ["CWE-416", "CWE-825"]}