{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2024-50241", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-10-21T19:36:19.976Z", "datePublished": "2024-11-09T10:14:51.119Z", "dateUpdated": "2026-08-05T11:42:42.206Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T11:42:42.206Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nNFSD: Initialize struct nfsd4_copy earlier\n\nEnsure the refcount and async_copies fields are initialized early.\ncleanup_async_copy() will reference these fields if an error occurs\nin nfsd4_copy(). If they are not correctly initialized, at the very\nleast, a refcount underflow occurs." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "baseScore": 7.5, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:N - The flaw is in nfsd's NFSv4.2 `OP_COPY` handler (`fs/nfsd/nfs4proc.c:nfsd4_copy()`), reached purely by sending a COMPOUND over TCP/2049 from a remote NFS client. The `ca_synchronous` flag that selects the vulnerable async branch is decoded directly from the wire in `nfsd4_decode_copy()`.\nAC:L - The attacker fully controls both trigger conditions — setting `ca_synchronous=false` and issuing more concurrent async COPYs than `sp_nrthreads` (default 8) by first parking several long-running copies. There is no race outside the attacker's control, no memory-layout dependency, and no unusual kernel configuration needed for the intra-server path.\nPR:N - Under AUTH_SYS — the default and overwhelmingly common NFS configuration — the server verifies no secret; a client simply asserts a UID to complete EXCHANGE_ID/CREATE_SESSION and OPEN the source/destination files, so no credentials in the CVSS sense are required. This matches the PR:N assigned to CVE-2024-53073, the companion fix to the identical error path.\nUI:N - The attacker's own COPY requests drive the entire sequence; no administrator or user on the NFS server has to open a file, mount anything, or take any action.\nS:U - The refcount underflow and leaked allocation are confined to the NFS server kernel's own memory and security authority, with no crossing into a hypervisor, IOMMU, or sandbox boundary.\nC:N - The underflow is caught by `refcount_warn_saturate()` and the object is simply never freed — there is no out-of-bounds read, no use-after-free of live data, and nothing from kernel memory is returned to the requesting client.\nI:N - No attacker-controlled write occurs: the leaked `struct nfsd4_copy` is unreachable and its refcount is saturated, so it is never reused or freed, yielding no corruption or control-flow primitive.\nA:H - `WARN_ONCE(\"refcount_t: underflow; use-after-free\")` panics the server outright on the common hardened/cloud setting `panic_on_warn=1`, and absent that, every triggering request permanently leaks a ~0.5 KB slab object, giving an unauthenticated remote client an unbounded kernel memory-exhaustion primitive that drives the NFS server to OOM." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/nfsd/nfs4proc.c" ], "versions": [ { "version": "9e52ff544e0bfa09ee339fd7b0937ee3c080c24e", "lessThan": "059434d23c4578d9d02efb92d848ea21bc640112", "status": "affected", "versionType": "git" }, { "version": "43e46ee5efc03990b223f7aa8b77aa9c3d3acfdf", "lessThan": "7267625baf365a969f1b25ded6f07b64bc90ec5b", "status": "affected", "versionType": "git" }, { "version": "7ea9260874b779637aff6d24c344b8ef4ac862a0", "lessThan": "c3074003fa6837c2b89a34d8d12d9463b59d22d6", "status": "affected", "versionType": "git" }, { "version": "ae267989b7b7933dfedcd26468d0a88fc3a9da9e", "lessThan": "421f1a2a1afb47d88de09457ef7687e1df7bc997", "status": "affected", "versionType": "git" }, { "version": "6a488ad7745b8f64625c6d3a24ce7e448e83f11b", "lessThan": "e30a9a2f69c34a00a3cb4fd45c5d231929e66fb1", "status": "affected", "versionType": "git" }, { "version": "aadc3bbea163b6caaaebfdd2b6c4667fbc726752", "lessThan": "63fab04cbd0f96191b6e5beedc3b643b01c15889", "status": "affected", "versionType": "git" }, { "version": "b4e21431a0db4854b5023cd5af001be557e6c3db", "status": "affected", "versionType": "git" }, { "version": "6.10.14", "lessThan": "6.11", "status": "affected", "versionType": "semver" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/nfsd/nfs4proc.c" ], "versions": [ { "version": "6.11.3", "lessThan": "6.11.7", "status": "affected", "versionType": "semver" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.11.3", "versionEndExcluding": "6.11.7" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.10.14" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/059434d23c4578d9d02efb92d848ea21bc640112" }, { "url": "https://git.kernel.org/stable/c/7267625baf365a969f1b25ded6f07b64bc90ec5b" }, { "url": "https://git.kernel.org/stable/c/c3074003fa6837c2b89a34d8d12d9463b59d22d6" }, { "url": "https://git.kernel.org/stable/c/421f1a2a1afb47d88de09457ef7687e1df7bc997" }, { "url": "https://git.kernel.org/stable/c/e30a9a2f69c34a00a3cb4fd45c5d231929e66fb1" }, { "url": "https://git.kernel.org/stable/c/63fab04cbd0f96191b6e5beedc3b643b01c15889" } ], "title": "NFSD: Initialize struct nfsd4_copy earlier", "x_generator": { "engine": "bippy-1.2.0" } } } }