{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2021-47001", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-02-27T18:42:55.950Z", "datePublished": "2024-02-28T08:13:23.482Z", "dateUpdated": "2026-08-05T08:45:30.039Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T08:45:30.039Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nxprtrdma: Fix cwnd update ordering\n\nAfter a reconnect, the reply handler is opening the cwnd (and thus\nenabling more RPC Calls to be sent) /before/ rpcrdma_post_recvs()\ncan post enough Receive WRs to receive their replies. This causes an\nRNR and the new connection is lost immediately.\n\nThe race is most clearly exposed when KASAN and disconnect injection\nare enabled. This slows down rpcrdma_rep_create() enough to allow\nthe send side to post a bunch of RPC Calls before the Receive\ncompletion handler can invoke ib_post_recv()." } ], "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 vulnerable path is the NFS/RPC-over-RDMA client receive completion handler (rpcrdma_wc_receive → rpcrdma_reply_handler) processing network-delivered RDMA replies and credit grants from a remote peer. A malicious or compromised NFS/RDMA server reaches this code over RoCE/iWARP/IB fabrics without local code execution on the client.\nAC:L - A remote peer controls reconnect timing, the credit grant size that widens post_recvs work, and reply latency, so it can drive sends before receives are posted. This is an attacker-influenced race rather than a condition solely dependent on unrelated victim state.\nPR:N - The attacking NFS/RDMA peer needs no privileges on the victim client; triggering occurs via ordinary RDMA reply traffic on an already-established transport. Local CAP_SYS_ADMIN is only needed to create the mount, not for the peer to exploit the connected client.\nUI:N - In the highest-impact scenario the client already has an active NFS/RDMA mount to a compromised or malicious storage server, and exploitation proceeds during reconnect/reply handling without further victim action.\nS:U - Impact is limited to the victim host’s NFS/RPC-over-RDMA transport availability and does not cross a VM, IOMMU, or other separate security authority.\nC:N - The bug only mis-orders cwnd update versus Receive posting, causing RNR and connection loss; there is no memory disclosure or corruption primitive.\nI:N - There is no attacker-controlled write, type confusion, or control-flow hijack; the failure mode is transport disconnect from RNR, not data or code integrity compromise.\nA:H - With rnr_retry_count set to 0, the race causes immediate RDMA connection loss after reconnect, denying NFS/RDMA service; a peer can repeat disconnect/reconnect to keep the mount unavailable." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/sunrpc/xprtrdma/rpc_rdma.c", "net/sunrpc/xprtrdma/verbs.c", "net/sunrpc/xprtrdma/xprt_rdma.h" ], "versions": [ { "version": "2ae50ad68cd79224198b525f7bd645c9da98b6ff", "lessThan": "eddae8be7944096419c2ae29477a45f767d0fcd4", "status": "affected", "versionType": "git" }, { "version": "2ae50ad68cd79224198b525f7bd645c9da98b6ff", "lessThan": "8834ecb5df22b7ff3c9b0deba7726579bb613f95", "status": "affected", "versionType": "git" }, { "version": "2ae50ad68cd79224198b525f7bd645c9da98b6ff", "lessThan": "19b5fa9489b5706bc878c3a522a7f771079e2fa0", "status": "affected", "versionType": "git" }, { "version": "2ae50ad68cd79224198b525f7bd645c9da98b6ff", "lessThan": "35d8b10a25884050bb3b0149b62c3818ec59f77c", "status": "affected", "versionType": "git" }, { "version": "3791c5982ba1eebf2900ee7ca7b9a89619c26d54", "status": "affected", "versionType": "git" }, { "version": "5.4.13", "lessThan": "5.5", "status": "affected", "versionType": "semver" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/sunrpc/xprtrdma/rpc_rdma.c", "net/sunrpc/xprtrdma/verbs.c", "net/sunrpc/xprtrdma/xprt_rdma.h" ], "versions": [ { "version": "5.5", "status": "affected" }, { "version": "0", "lessThan": "5.5", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.38", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.11.22", "lessThanOrEqual": "5.11.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.12.5", "lessThanOrEqual": "5.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.13", "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": "5.5", "versionEndExcluding": "5.10.38" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.5", "versionEndExcluding": "5.11.22" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.5", "versionEndExcluding": "5.12.5" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.5", "versionEndExcluding": "5.13" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.4.13" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/eddae8be7944096419c2ae29477a45f767d0fcd4" }, { "url": "https://git.kernel.org/stable/c/8834ecb5df22b7ff3c9b0deba7726579bb613f95" }, { "url": "https://git.kernel.org/stable/c/19b5fa9489b5706bc878c3a522a7f771079e2fa0" }, { "url": "https://git.kernel.org/stable/c/35d8b10a25884050bb3b0149b62c3818ec59f77c" } ], "title": "xprtrdma: Fix cwnd update ordering", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "title": "CISA ADP Vulnrichment", "metrics": [ { "other": { "type": "ssvc", "content": { "id": "CVE-2021-47001", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "partial" } ], "version": "2.0.3", "timestamp": "2024-03-05T16:58:29.225383Z" } } } ], "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2024-06-04T17:14:54.379Z" } }, { "title": "CVE Program Container", "references": [ { "url": "https://git.kernel.org/stable/c/eddae8be7944096419c2ae29477a45f767d0fcd4", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/8834ecb5df22b7ff3c9b0deba7726579bb613f95", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/19b5fa9489b5706bc878c3a522a7f771079e2fa0", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/35d8b10a25884050bb3b0149b62c3818ec59f77c", "tags": [ "x_transferred" ] }, { "url": "https://security.netapp.com/advisory/ntap-20250411-0001/" } ], "providerMetadata": { "orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2025-04-11T22:03:12.324Z" } } ] } }