{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2025-22025", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-12-29T08:45:45.807Z", "datePublished": "2025-04-16T14:11:46.624Z", "dateUpdated": "2026-08-05T11:56:05.741Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T11:56:05.741Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: put dl_stid if fail to queue dl_recall\n\nBefore calling nfsd4_run_cb to queue dl_recall to the callback_wq, we\nincrement the reference count of dl_stid.\nWe expect that after the corresponding work_struct is processed, the\nreference count of dl_stid will be decremented through the callback\nfunction nfsd4_cb_recall_release.\nHowever, if the call to nfsd4_run_cb fails, the incremented reference\ncount of dl_stid will not be decremented correspondingly, leading to the\nfollowing nfs4_stid leak:\nunreferenced object 0xffff88812067b578 (size 344):\n comm \"nfsd\", pid 2761, jiffies 4295044002 (age 5541.241s)\n hex dump (first 32 bytes):\n 01 00 00 00 6b 6b 6b 6b b8 02 c0 e2 81 88 ff ff ....kkkk........\n 00 6b 6b 6b 6b 6b 6b 6b 00 00 00 00 ad 4e ad de .kkkkkkk.....N..\n backtrace:\n kmem_cache_alloc+0x4b9/0x700\n nfsd4_process_open1+0x34/0x300\n nfsd4_open+0x2d1/0x9d0\n nfsd4_proc_compound+0x7a2/0xe30\n nfsd_dispatch+0x241/0x3e0\n svc_process_common+0x5d3/0xcc0\n svc_process+0x2a3/0x320\n nfsd+0x180/0x2e0\n kthread+0x199/0x1d0\n ret_from_fork+0x30/0x50\n ret_from_fork_asm+0x1b/0x30\nunreferenced object 0xffff8881499f4d28 (size 368):\n comm \"nfsd\", pid 2761, jiffies 4295044005 (age 5541.239s)\n hex dump (first 32 bytes):\n 01 00 00 00 00 00 00 00 30 4d 9f 49 81 88 ff ff ........0M.I....\n 30 4d 9f 49 81 88 ff ff 20 00 00 00 01 00 00 00 0M.I.... .......\n backtrace:\n kmem_cache_alloc+0x4b9/0x700\n nfs4_alloc_stid+0x29/0x210\n alloc_init_deleg+0x92/0x2e0\n nfs4_set_delegation+0x284/0xc00\n nfs4_open_delegation+0x216/0x3f0\n nfsd4_process_open2+0x2b3/0xee0\n nfsd4_open+0x770/0x9d0\n nfsd4_proc_compound+0x7a2/0xe30\n nfsd_dispatch+0x241/0x3e0\n svc_process_common+0x5d3/0xcc0\n svc_process+0x2a3/0x320\n nfsd+0x180/0x2e0\n kthread+0x199/0x1d0\n ret_from_fork+0x30/0x50\n ret_from_fork_asm+0x1b/0x30\nFix it by checking the result of nfsd4_run_cb and call nfs4_put_stid if\nfail to queue dl_recall." } ], "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 bug is in the in-kernel NFSv4 server (fs/nfsd/nfs4state.c) delegation-recall path; a remote NFS client drives it entirely over the network by obtaining a delegation via OPEN and then issuing conflicting opens that trigger nfsd_break_deleg_cb/nfsd_break_one_deleg.\nAC:L - The attacker controls both sides: it obtains the write delegation itself, then issues a read-open (FL_DOWNGRADE_PENDING break) followed by a write-open (FL_UNLOCK_PENDING break), producing two lm_break calls; because cl_callback_wq is an alloc_ordered_workqueue (max_active=1) that the attacker can keep backed up with other pending callbacks, dl_recall stays in the WORK_STRUCT_PENDING state long enough that the second queue_work() reliably fails and leaks the refcount.\nPR:N - NFSv4 OPEN and delegation acquisition on a typical AUTH_SYS export require no verified credentials — any host permitted by the export list can mount and self-assert a uid — so the code is reachable by an unauthenticated network peer, matching prior nfsd OPEN/delegation-path scoring.\nUI:N - No victim action is needed; the attacker's own client (or two of its threads/connections) supplies both the delegation and the conflicting opens that force the lease break.\nS:U - The leaked references and their consequences are confined to the kernel's own memory and the nfsd subsystem; no security authority boundary such as a VM or IOMMU domain is crossed.\nC:N - The defect is a reference count that is incremented and never dropped, so objects live longer than intended rather than being freed early; there is no out-of-bounds read, no use-after-free, and no path by which attacker-visible data is disclosed.\nI:N - Nothing is written out of bounds or freed prematurely — the missing nfs4_put_stid only over-holds a valid object — so no kernel or file data can be modified through this bug.\nA:H - Each occurrence permanently leaks an nfs4_delegation/nfs4_stid (344 + 368 bytes) and pins the associated nfs4_file, nfsd_file and inode, and the attacker can repeat this across arbitrarily many files for unbounded kernel memory exhaustion leading to OOM; it additionally trips WARN_ON_ONCE (a panic under panic_on_warn), prevents the exported filesystem from being unmounted, and leaves nfsd_file objects outstanding at nfs-server shutdown." } ] } ], "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": "b5a1a81e5c25fb6bb3fdc1812ba69ff6ab638fcf", "lessThan": "b874cdef4e67e5150e07eff0eae1cbb21fb92da1", "status": "affected", "versionType": "git" }, { "version": "b5a1a81e5c25fb6bb3fdc1812ba69ff6ab638fcf", "lessThan": "cdb796137c57e68ca34518d53be53b679351eb86", "status": "affected", "versionType": "git" }, { "version": "b5a1a81e5c25fb6bb3fdc1812ba69ff6ab638fcf", "lessThan": "d96587cc93ec369031bcd7658c6adc719873c9fd", "status": "affected", "versionType": "git" }, { "version": "b5a1a81e5c25fb6bb3fdc1812ba69ff6ab638fcf", "lessThan": "9a81cde8c7ce65dd90fb47ceea93a45fc1a2fbd1", "status": "affected", "versionType": "git" }, { "version": "b5a1a81e5c25fb6bb3fdc1812ba69ff6ab638fcf", "lessThan": "cad3479b63661a399c9df1d0b759e1806e2df3c8", "status": "affected", "versionType": "git" }, { "version": "b5a1a81e5c25fb6bb3fdc1812ba69ff6ab638fcf", "lessThan": "63b91c8ff4589f5263873b24c052447a28e10ef7", "status": "affected", "versionType": "git" }, { "version": "b5a1a81e5c25fb6bb3fdc1812ba69ff6ab638fcf", "lessThan": "133f5e2a37ce08c82d24e8fba65e0a81deae4609", "status": "affected", "versionType": "git" }, { "version": "b5a1a81e5c25fb6bb3fdc1812ba69ff6ab638fcf", "lessThan": "230ca758453c63bd38e4d9f4a21db698f7abada8", "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": "2.6.35", "status": "affected" }, { "version": "0", "lessThan": "2.6.35", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.236", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.180", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.134", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.87", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.23", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.13.11", "lessThanOrEqual": "6.13.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.14.2", "lessThanOrEqual": "6.14.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.15", "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": "2.6.35", "versionEndExcluding": "5.10.236" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.35", "versionEndExcluding": "5.15.180" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.35", "versionEndExcluding": "6.1.134" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.35", "versionEndExcluding": "6.6.87" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.35", "versionEndExcluding": "6.12.23" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.35", "versionEndExcluding": "6.13.11" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.35", "versionEndExcluding": "6.14.2" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.35", "versionEndExcluding": "6.15" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/b874cdef4e67e5150e07eff0eae1cbb21fb92da1" }, { "url": "https://git.kernel.org/stable/c/cdb796137c57e68ca34518d53be53b679351eb86" }, { "url": "https://git.kernel.org/stable/c/d96587cc93ec369031bcd7658c6adc719873c9fd" }, { "url": "https://git.kernel.org/stable/c/9a81cde8c7ce65dd90fb47ceea93a45fc1a2fbd1" }, { "url": "https://git.kernel.org/stable/c/cad3479b63661a399c9df1d0b759e1806e2df3c8" }, { "url": "https://git.kernel.org/stable/c/63b91c8ff4589f5263873b24c052447a28e10ef7" }, { "url": "https://git.kernel.org/stable/c/133f5e2a37ce08c82d24e8fba65e0a81deae4609" }, { "url": "https://git.kernel.org/stable/c/230ca758453c63bd38e4d9f4a21db698f7abada8" } ], "title": "nfsd: put dl_stid if fail to queue dl_recall", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "title": "CVE Program Container", "references": [ { "url": "https://lists.debian.org/debian-lts-announce/2025/05/msg00045.html" }, { "url": "https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html" } ], "providerMetadata": { "orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2025-11-03T19:41:12.024Z" } } ] } }