{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2024-56563",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2024-12-27T14:03:05.994Z",
        "datePublished": "2024-12-27T14:23:07.854Z",
        "dateUpdated": "2026-08-05T11:45:07.489Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-08-05T11:45:07.489Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nceph: fix cred leak in ceph_mds_check_access()\n\nget_current_cred() increments the reference counter, but the\nput_cred() call was missing."
                }
            ],
            "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 - The leak is triggered by ordinary local VFS syscalls (`open`, `creat`, `unlink`, `chmod`, `truncate`) issued against a mounted CephFS; no network peer input reaches the vulnerable function directly.\nAC:L - The missing `put_cred()` is unconditional — every single call to `ceph_mds_check_access()` leaks a reference with no race, timing window, or special configuration required, so a trivial loop drives the leak deterministically.\nPR:L - Any unprivileged local user with access to a path on an already-mounted CephFS can trigger it; the call sites in `ceph_open()`/`ceph_atomic_open()`/`ceph_unlink()`/`__ceph_setattr() ` are reached before any capability or auth gate.\nUI:N - No action by another user is needed — the attacker triggers the leak entirely on their own via normal file operations on the existing mount.\nS:U - The leaked credentials and any resulting corruption stay within the kernel's own security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - The leaked object is `struct cred`, incremented through an unchecked `atomic_long_add()` with no `refcount_t` saturation; on 32-bit builds the counter wraps at 2^32, freeing a live credential structure and yielding a use-after-free read primitive over uid/gid/capability fields.\nI:H - The same credential refcount imbalance/overflow permits a freed `cred` to be reallocated and overwritten by attacker-controlled heap content — the classic CVE-2016-0728-style path to arbitrary modification of `cap_effective`/`euid` and full local privilege escalation.\nA:H - Each operation permanently pins a `cred` plus its `user_struct`, `user_namespace`, `ucounts`, `group_info` and keyrings, so an unprivileged loop produces an unbounded, unreclaimable kernel memory leak ending in OOM, and the 32-bit refcount wrap causes an outright UAF crash."
                        }
                    ]
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "fs/ceph/mds_client.c"
                    ],
                    "versions": [
                        {
                            "version": "596afb0b8933ba6ed7227adcc538db26feb25c74",
                            "lessThan": "e3d1c9e2b811f13bdbbb962c2b17a6091c28522c",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "596afb0b8933ba6ed7227adcc538db26feb25c74",
                            "lessThan": "c5cf420303256dcd6ff175643e9e9558543c2047",
                            "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/ceph/mds_client.c"
                    ],
                    "versions": [
                        {
                            "version": "6.10",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "6.10",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.12.4",
                            "lessThanOrEqual": "6.12.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.13",
                            "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": "6.10",
                                    "versionEndExcluding": "6.12.4"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "6.10",
                                    "versionEndExcluding": "6.13"
                                }
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                    ]
                }
            ],
            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/e3d1c9e2b811f13bdbbb962c2b17a6091c28522c"
                },
                {
                    "url": "https://git.kernel.org/stable/c/c5cf420303256dcd6ff175643e9e9558543c2047"
                }
            ],
            "title": "ceph: fix cred leak in ceph_mds_check_access()",
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    }
}