{
    "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",
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}