{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-90235", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.794Z", "datePublished": "2026-09-17T16:07:41.251Z", "dateUpdated": "2026-10-30T12:34:53.963Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-30T12:34:53.963Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsunrpc: xprtsock: annotate shared socket callbacks with READ_ONCE/WRITE_ONCE\n\nxprtsock replaces and restores sk->sk_data_ready and\nsk->sk_write_space on live sockets with plain stores, and\nxs_udp_do_set_buffer_size() invokes sk->sk_write_space via a plain\nload. These callback pointers are shared with generic socket and\nprotocol paths that may read or invoke them concurrently, so xprtsock\nneeds the same READ_ONCE()/WRITE_ONCE() callback visibility contract\nthat the validated 4022 family applied elsewhere.\n\nWhen SUNRPC takes over an AF_LOCAL, UDP, or TCP socket and later\nrestores the lower-socket callbacks during teardown, another CPU may\nstill hold an earlier callback snapshot. The plain replace/restore\npattern leaves the same visibility hole as the validated 4022 family,\nso a stale snapshot can still invoke xs_data_ready() or\nxs_udp_write_space() after the live callback fields have already been\nrestored to the lower-socket handlers.\n\nUse WRITE_ONCE() for the shared sk_data_ready and sk_write_space\nstores in xs_local_finish_connecting(), xs_udp_finish_connecting(),\nxs_tcp_finish_connecting(), and xs_restore_old_callbacks(). Use\nREAD_ONCE() for the direct sk_write_space invocation in\nxs_udp_do_set_buffer_size(). This matches the required callback\nvisibility contract while leaving adjacent sk_state_change and\nsk_error_report handling unchanged." } ], "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 - NFSv4.0 SETCLIENTID/SETCLIENTID_CONFIRM (nfsd4_setclientid → gen_callback → setup_callback_client with XPRT_TRANSPORT_TCP) makes nfsd run xs_tcp_finish_connecting; the peer's callback TCP segments hit READ_ONCE(sk_data_ready) in tcp_data_queue and READ_ONCE(sk_write_space) in sock_wfree. NFS client RPC-over-TCP/UDP replies use the same xprtsock callbacks.\nAC:L - The attacker drives both sides: SETCLIENTID_CONFIRM then a later SETCLIENTID or TCP RST forces xs_tcp_finish_connecting versus xs_restore_old_callbacks (nfsd4_process_cb_update → rpc_shutdown_client → xs_reset_transport), while concurrent callback replies and TX skb frees take sock_wfree's lockless sk_write_space snapshot. The race is retryable on new callback sockets.\nPR:N - SETCLIENTID and SETCLIENTID_CONFIRM are ALLOWED_WITHOUT_FH. Typical nfsd deployments accept AUTH_SYS/AUTH_NULL, so a remote peer that can reach TCP/2049 needs no local account or capability on the NFS server to create and tear down the callback xprtsock.\nUI:N - The attacker sends SETCLIENTID/SETCLIENTID_CONFIRM and the callback-channel TCP segments itself. No victim mount or other interactive action is required beyond nfsd already serving NFSv4.0.\nS:U - Stale xs_data_ready or xs_udp_write_space running against a torn-down sock_xprt corrupts kernel memory on the host that owns the RPC socket. This is not a guest-to-host, IOMMU, or other cross-authority escape.\nC:H - A stale xs_data_ready after xs_restore_old_callbacks can still see a non-NULL sk_user_data via xprt_from_sock and call transport->old_data_ready plus read sock_xprt fields, leaking kernel heap once that xprt is reused or freed.\nI:H - The same callback/user_data desync lets xs_write_space queue_work on a freed recv_worker/error_worker and decrement sk_write_pending while xs_reset_transport is in __fput_sync, giving an arbitrary kernel write and control-flow hijack.\nA:H - Use-after-free of sock_xprt in xs_data_ready, xs_udp_write_space, or xs_tcp_write_space from sock_wfree or tcp_data_queue after xs_restore_old_callbacks oopses or panics the kernel even without a full write primitive." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/sunrpc/xprtsock.c" ], "versions": [ { "version": "a246b0105bbd9a70a698f69baae2042996f2a0e9", "lessThan": "6b79b5a0f1c566f0aa6e08c7981826015a0acc4d", "status": "affected", "versionType": "git" }, { "version": "a246b0105bbd9a70a698f69baae2042996f2a0e9", "lessThan": "ed80d009b154aa204f541d390884851b3d4f15ae", "status": "affected", "versionType": "git" }, { "version": "a246b0105bbd9a70a698f69baae2042996f2a0e9", "lessThan": "589f761236e05ff9de1bdfd6a5258f113e6457fe", "status": "affected", "versionType": "git" }, { "version": "a246b0105bbd9a70a698f69baae2042996f2a0e9", "lessThan": "da652cb17f9faeea1fa44b7215e8869a0b10b664", "status": "affected", "versionType": "git" }, { "version": "a246b0105bbd9a70a698f69baae2042996f2a0e9", "lessThan": "d8f0b83753809761a560c4b33249388548ba6e43", "status": "affected", "versionType": "git" }, { "version": "a246b0105bbd9a70a698f69baae2042996f2a0e9", "lessThan": "33930840b5f0a79f826e7c69dc6cd78f72a67481", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/sunrpc/xprtsock.c" ], "versions": [ { "version": "2.6.15", "status": "affected" }, { "version": "0", "lessThan": "2.6.15", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.191", "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": "2.6.15", "versionEndExcluding": "6.1.191" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.15", "versionEndExcluding": "6.6.157" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.15", "versionEndExcluding": "6.12.110" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.15", "versionEndExcluding": "6.18.52" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.15", "versionEndExcluding": "7.2.6" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.15", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/6b79b5a0f1c566f0aa6e08c7981826015a0acc4d" }, { "url": "https://git.kernel.org/stable/c/ed80d009b154aa204f541d390884851b3d4f15ae" }, { "url": "https://git.kernel.org/stable/c/589f761236e05ff9de1bdfd6a5258f113e6457fe" }, { "url": "https://git.kernel.org/stable/c/da652cb17f9faeea1fa44b7215e8869a0b10b664" }, { "url": "https://git.kernel.org/stable/c/d8f0b83753809761a560c4b33249388548ba6e43" }, { "url": "https://git.kernel.org/stable/c/33930840b5f0a79f826e7c69dc6cd78f72a67481" } ], "title": "sunrpc: xprtsock: annotate shared socket callbacks with READ_ONCE/WRITE_ONCE", "x_generator": { "engine": "bippy-1.2.0" } } } }