{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-89526", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.719Z", "datePublished": "2026-09-11T19:44:07.043Z", "dateUpdated": "2026-10-21T12:47:39.359Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-21T12:47:39.359Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsvcrdma: Validate Read chunk positions before reconstruction\n\nThe RPC/RDMA Read chunk position field is supplied by the remote\nclient and stored verbatim in the parsed chunk list.\nxdr_count_read_segments() checks only 4-byte alignment; it never\ncompares the position against the received inline body length.\n\nIn the single-chunk path, svc_rdma_read_complete_one() splits the\nhead and tail kvecs at ch_position. A position past the inline\nbody underflows the tail length, exposing adjacent slab memory to\nthe upper XDR decoder.\n\nIn the multi-chunk path, svc_rdma_read_multiple_chunks() computes\ngap lengths between chunks as unsigned subtractions from\nch_position. Overlapping Read chunks cause these subtractions to\nunderflow. A final position past the inline body likewise\nunderflows the trailing gap length. svc_rdma_copy_inline_range()\nthen copies past the receive buffer into request pages that are\nreturned to the client through the Reply channel.\n\nBound inline-range copies in svc_rdma_copy_inline_range() against\nthe decoded inline RPC body saved in rc_saved_arg. Reject a\nsingle Read chunk positioned beyond that body, and reject\nmulti-chunk lists where accumulated read bytes exceed the next\nchunk's position. Apply the same position and overlap checks in\nthe call-chunk interleaving path." } ], "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 - svcrdma is nfsd's RPC-over-RDMA transport; a remote peer reaches Read-chunk reconstruction on an enabled NFS/RDMA listener over routable iWARP or RoCE, consistent with prior kernel CNA scores for this subsystem.\nAC:L - The attacker fully controls the wire-supplied Read-chunk position (only 4-byte alignment is checked) and can deterministically underflow gap/tail lengths or copy past the receive buffer, with no race or uncontrollable layout required.\nPR:N - svc_rdma_process_read_list() and svc_rdma_read_complete_one() run in svc_rdma_recvfrom() while assembling the transport message, before svc_process() performs RPC or NFS authentication, and RDMA CM accept has no credential check.\nUI:N - Sending a crafted RPC-over-RDMA message with a malicious Read list is sufficient; no victim mount, click, or other user action is required.\nS:U - The vulnerable NFS/RDMA service and the affected kernel memory belong to the same host kernel security authority; this is not a VM, IOMMU, or sandbox escape.\nC:H - A position past the inline body underflows the tail kvec so the XDR decoder reads adjacent slab, and overlapping chunks make svc_rdma_copy_inline_range() memcpy past the receive buffer into request pages returned on the Reply channel, disclosing kernel memory.\nI:H - The reconstructed xdr_buf uses attacker-controlled head/tail lengths pointing into adjacent slab; XDR shift/copy helpers then memcpy through those kvecs, producing an out-of-bounds kernel write that can corrupt adjacent objects and hijack control flow.\nA:H - The unbounded inline copy and inflated kvec lengths walk unmapped memory or trip decoder/WARN paths, causing a kernel oops or panic that an unauthenticated peer can trigger repeatedly." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/sunrpc/xprtrdma/svc_rdma_rw.c" ], "versions": [ { "version": "d96962e6d0e281bab6a48e83b42f5dce6eb28bf4", "lessThan": "3861eeabaebe243050952b34063763527c44e1fe", "status": "affected", "versionType": "git" }, { "version": "d96962e6d0e281bab6a48e83b42f5dce6eb28bf4", "lessThan": "5ab3f6d882fe07ae5e61d0bcfeea00b9409155c2", "status": "affected", "versionType": "git" }, { "version": "d96962e6d0e281bab6a48e83b42f5dce6eb28bf4", "lessThan": "f84ec84d8d4bc65f9ae23372570349687f66fa39", "status": "affected", "versionType": "git" }, { "version": "d96962e6d0e281bab6a48e83b42f5dce6eb28bf4", "lessThan": "577097455d084610fc31e91e6a61c5793b6f04ba", "status": "affected", "versionType": "git" }, { "version": "d96962e6d0e281bab6a48e83b42f5dce6eb28bf4", "lessThan": "3779b7b9e7d1c8ba4738f9d327de3b0288cefe9b", "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/xprtrdma/svc_rdma_rw.c" ], "versions": [ { "version": "5.11", "status": "affected" }, { "version": "0", "lessThan": "5.11", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.160", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.109", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.50", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.4", "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": "5.11", "versionEndExcluding": "6.6.160" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.11", "versionEndExcluding": "6.12.109" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.11", "versionEndExcluding": "6.18.50" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.11", "versionEndExcluding": "7.2.4" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.11", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/3861eeabaebe243050952b34063763527c44e1fe" }, { "url": "https://git.kernel.org/stable/c/5ab3f6d882fe07ae5e61d0bcfeea00b9409155c2" }, { "url": "https://git.kernel.org/stable/c/f84ec84d8d4bc65f9ae23372570349687f66fa39" }, { "url": "https://git.kernel.org/stable/c/577097455d084610fc31e91e6a61c5793b6f04ba" }, { "url": "https://git.kernel.org/stable/c/3779b7b9e7d1c8ba4738f9d327de3b0288cefe9b" } ], "title": "svcrdma: Validate Read chunk positions before reconstruction", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "id": "CVE-2026-89526", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "yes" }, { "Technical Impact": "total" } ], "version": "2.0.3", "timestamp": "2026-10-16T19:22:57.126783Z" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-16T19:26:40.839Z" } } ] } }