{"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":"2026-09-18T17:53:26.660Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-09-18T17:53:26.660Z"},"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-rc1","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-rc1"}]}]}],"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"}}}}