{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-90151", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.789Z", "datePublished": "2026-09-17T16:06:44.987Z", "dateUpdated": "2026-10-19T08:58:50.239Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T08:58:50.239Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nNFSv4: remove callback IDR entry on client allocation failure\n\nnfs4_alloc_client() allocates an NFSv4.0 callback identifier before it\nfinishes setting up the client. If any later initialization step fails,\nthe error path frees the nfs_client directly with nfs_free_client(). That\nbypasses nfs_put_client(), which is where the callback IDR entry is\nremoved during normal teardown.\n\nA failed allocation can therefore leave cb_ident_idr pointing at a freed\nnfs_client. A later NFSv4.0 callback lookup by cb_ident would find the\nstale pointer and take a reference to it.\n\nMake the callback IDR removal helper callable by the allocation failure\npath, and remove the callback identifier before freeing the client.\n\nThis was found by a local static-analysis checker for publish-before-free\nlifetime bugs and confirmed by manual inspection." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 9.8, "baseSeverity": "CRITICAL" }, "scenarios": [ { "lang": "en", "value": "AV:N - nfs4_find_client_ident() is called from nfs4_callback_compound() with hdr_arg.cb_ident taken by decode_compound_hdr_arg() from an NFSv4.0 CB_COMPOUND on the TCP callback listener that nfs4_callback_up_net() binds to INADDR_ANY via svc_xprt_create(); the remote peer supplies that identifier over routable TCP.\nAC:L - A malicious NFSv4.0 server keeps the callback service up, then forces a later nfs4_alloc_client() to fail after nfs_get_cb_ident_idr() by making rpc_create()/rpc_ping() fail in nfs_create_rpc_client() (nfs4_create_referral_server or nfs4_update_server to an RST-ing address), then sends CB_COMPOUND with the next sequential idr id; no uncontrolled race is required.\nPR:N - nfs4_find_client_ident() runs in nfs4_callback_compound() before check_gss_callback_principal(), and nfs_callback_authenticate() accepts RPC_AUTH_UNIX for CB_COMPOUND, so the peer needs no account or capability on the victim client.\nUI:N - The same peer returns NFS4ERR_MOVED so nfs4_schedule_migration_recovery() or a LOOKUP referral (nfs4_create_referral_server) runs nfs4_alloc_client() from the state manager or automount, then sends the CB_COMPOUND itself; no extra victim mount dialog or file-open is required.\nS:U - The UAF is of an nfs_client published in cb_ident_idr and freed by nfs_free_client(); impact stays in the host kernel and does not cross a VM, IOMMU, or guest/host boundary.\nC:H - nfs4_find_client_ident() does refcount_inc(&clp->cl_count) on the nfs_client that nfs_free_client() already kfree_rcu'd, so a stale cb_ident_idr pointer remains; reclaim of that heap object yields an arbitrary kernel read, as with other kernel UAFs.\nI:H - The same stale-IDR lookup is a use-after-free write (refcount_inc, then nfs_put_client list_del and field access in check_gss_callback_principal/process_op); spraying the freed nfs_client enables arbitrary write and control-flow hijack.\nA:H - refcount_inc on the kfree_rcu'd nfs_client, or later dereference of cl_rpcclient left as ERR_PTR(-EINVAL) when nfs_create_rpc_client() failed, causes a kernel oops/panic even without a full exploit." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/nfs/client.c", "fs/nfs/internal.h", "fs/nfs/nfs4client.c" ], "versions": [ { "version": "f4eecd5da3422e82e88e36c33cbd2595eebcacb1", "lessThan": "68c721391b761dbe38d5b0094d2bb6e8489ad92b", "status": "affected", "versionType": "git" }, { "version": "f4eecd5da3422e82e88e36c33cbd2595eebcacb1", "lessThan": "9bfdd0f591307b5198826a0e7a5b2f35f87acd2d", "status": "affected", "versionType": "git" }, { "version": "f4eecd5da3422e82e88e36c33cbd2595eebcacb1", "lessThan": "7c4812eb96bdcafb31a65b12f2aa96659429d1d4", "status": "affected", "versionType": "git" }, { "version": "f4eecd5da3422e82e88e36c33cbd2595eebcacb1", "lessThan": "fc95ca82d5ae598c428ab5a00ae69f8526d59371", "status": "affected", "versionType": "git" }, { "version": "f4eecd5da3422e82e88e36c33cbd2595eebcacb1", "lessThan": "80b1c3d5a881f7d9081aa9f46da9742878a0f893", "status": "affected", "versionType": "git" }, { "version": "f4eecd5da3422e82e88e36c33cbd2595eebcacb1", "lessThan": "3f2387e8bfbc4efda5d77c3a11a028d0a119c48f", "status": "affected", "versionType": "git" }, { "version": "f4eecd5da3422e82e88e36c33cbd2595eebcacb1", "lessThan": "5891c03e150920618db0e9c4ea2d772abacdcfd1", "status": "affected", "versionType": "git" }, { "version": "f4eecd5da3422e82e88e36c33cbd2595eebcacb1", "lessThan": "d05c2007b3d84ccba11dc6e9cb3202768cc72f14", "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/nfs/client.c", "fs/nfs/internal.h", "fs/nfs/nfs4client.c" ], "versions": [ { "version": "2.6.38", "status": "affected" }, { "version": "0", "lessThan": "2.6.38", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.270", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.221", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.188", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.157", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.110", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.52", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.6", "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": "2.6.38", "versionEndExcluding": "5.10.270" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.38", "versionEndExcluding": "5.15.221" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.38", "versionEndExcluding": "6.1.188" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.38", "versionEndExcluding": "6.6.157" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.38", "versionEndExcluding": "6.12.110" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.38", "versionEndExcluding": "6.18.52" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.38", "versionEndExcluding": "7.2.6" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.38", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/68c721391b761dbe38d5b0094d2bb6e8489ad92b" }, { "url": "https://git.kernel.org/stable/c/9bfdd0f591307b5198826a0e7a5b2f35f87acd2d" }, { "url": "https://git.kernel.org/stable/c/7c4812eb96bdcafb31a65b12f2aa96659429d1d4" }, { "url": "https://git.kernel.org/stable/c/fc95ca82d5ae598c428ab5a00ae69f8526d59371" }, { "url": "https://git.kernel.org/stable/c/80b1c3d5a881f7d9081aa9f46da9742878a0f893" }, { "url": "https://git.kernel.org/stable/c/3f2387e8bfbc4efda5d77c3a11a028d0a119c48f" }, { "url": "https://git.kernel.org/stable/c/5891c03e150920618db0e9c4ea2d772abacdcfd1" }, { "url": "https://git.kernel.org/stable/c/d05c2007b3d84ccba11dc6e9cb3202768cc72f14" } ], "title": "NFSv4: remove callback IDR entry on client allocation failure", "x_generator": { "engine": "bippy-1.2.0" } } } }