{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2022-50241", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-09-15T13:58:00.971Z", "datePublished": "2025-09-15T14:01:47.539Z", "dateUpdated": "2026-08-05T08:57:53.698Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T08:57:53.698Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nNFSD: fix use-after-free on source server when doing inter-server copy\n\nUse-after-free occurred when the laundromat tried to free expired\ncpntf_state entry on the s2s_cp_stateids list after inter-server\ncopy completed. The sc_cp_list that the expired copy state was\ninserted on was already freed.\n\nWhen COPY completes, the Linux client normally sends LOCKU(lock_state x),\nFREE_STATEID(lock_state x) and CLOSE(open_state y) to the source server.\nThe nfs4_put_stid call from nfsd4_free_stateid cleans up the copy state\nfrom the s2s_cp_stateids list before freeing the lock state's stid.\n\nHowever, sometimes the CLOSE was sent before the FREE_STATEID request.\nWhen this happens, the nfsd4_close_open_stateid call from nfsd4_close\nfrees all lock states on its st_locks list without cleaning up the copy\nstate on the sc_cp_list list. When the time the FREE_STATEID arrives the\nserver returns BAD_STATEID since the lock state was freed. This causes\nthe use-after-free error to occur when the laundromat tries to free\nthe expired cpntf_state.\n\nThis patch adds a call to nfs4_free_cpntf_statelist in\nnfsd4_close_open_stateid to clean up the copy state before calling\nfree_ol_stateid_reaplist to free the lock state's stid on the reaplist." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 8.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:N - The flaw is in the in-kernel NFS server (nfsd); COPY_NOTIFY, CLOSE, and FREE_STATEID are processed from NFSv4.2 compounds over the network (TCP/2049), so a remote NFS client reaches the vulnerable path.\nAC:L - A malicious client fully controls the sequence—OPEN/LOCK, COPY_NOTIFY to attach cpntf_state to sc_cp_list, then CLOSE before FREE_STATEID—so the dangling cpntf entry and subsequent laundromat list_del are deterministic with no race outside attacker control.\nPR:L - The attacker must be an established NFSv4.2 client of an export with a valid open/lock stateid to issue COPY_NOTIFY, which is authenticated low-privilege service access rather than a pre-authentication path.\nUI:N - No victim action is required; the attacking client drives every NFS operation, and the server's own laundromat worker triggers the use-after-free after lease expiry.\nS:U - The use-after-free corrupts kernel slab memory within the host nfsd security authority and does not cross a VM, IOMMU, or sandbox boundary.\nC:H - The dangling cpntf_state remains linked into a freed parent stateid's sc_cp_list; reclaim of that slab object lets an attacker who grooms the heap control freed contents, enabling arbitrary kernel memory disclosure.\nI:H - Laundromat's list_del on the stale cp_list writes heap pointers into the freed, potentially reallocated stateid_slab object—a classic UAF write primitive usable for controlled memory modification and control-flow hijacking.\nA:H - The list corruption reliably causes a kernel oops/BUG/panic in laundromat_main when freeing the expired cpntf_state, fully disrupting availability of the NFS server host." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/nfsd/nfs4state.c" ], "versions": [ { "version": "624322f1adc58acd0b69f77a6ddc764207e97241", "lessThan": "bbacfcde5fff25ac22597e8373a065c647da6738", "status": "affected", "versionType": "git" }, { "version": "624322f1adc58acd0b69f77a6ddc764207e97241", "lessThan": "83b94969751a691347606dbe6b1865efcfa5a643", "status": "affected", "versionType": "git" }, { "version": "624322f1adc58acd0b69f77a6ddc764207e97241", "lessThan": "6ea71246b7a02af675d733e72d14bd0d591d5f4a", "status": "affected", "versionType": "git" }, { "version": "624322f1adc58acd0b69f77a6ddc764207e97241", "lessThan": "35aa0fb8c3033a3d78603356e96fc18c5b9cceb2", "status": "affected", "versionType": "git" }, { "version": "624322f1adc58acd0b69f77a6ddc764207e97241", "lessThan": "019805fea91599b22dfa62ffb29c022f35abeb06", "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/nfsd/nfs4state.c" ], "versions": [ { "version": "5.6", "status": "affected" }, { "version": "0", "lessThan": "5.6", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.150", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.75", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.19.17", "lessThanOrEqual": "5.19.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.0.3", "lessThanOrEqual": "6.0.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1", "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": "5.6", "versionEndExcluding": "5.10.150" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.6", "versionEndExcluding": "5.15.75" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.6", "versionEndExcluding": "5.19.17" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.6", "versionEndExcluding": "6.0.3" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.6", "versionEndExcluding": "6.1" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/bbacfcde5fff25ac22597e8373a065c647da6738" }, { "url": "https://git.kernel.org/stable/c/83b94969751a691347606dbe6b1865efcfa5a643" }, { "url": "https://git.kernel.org/stable/c/6ea71246b7a02af675d733e72d14bd0d591d5f4a" }, { "url": "https://git.kernel.org/stable/c/35aa0fb8c3033a3d78603356e96fc18c5b9cceb2" }, { "url": "https://git.kernel.org/stable/c/019805fea91599b22dfa62ffb29c022f35abeb06" } ], "title": "NFSD: fix use-after-free on source server when doing inter-server copy", "x_generator": { "engine": "bippy-1.2.0" } } } }