{"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":"2026-09-13T06:30:24.722Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-09-13T06:30:24.722Z"},"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":"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":"6.12.109","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-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":"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-rc1"}]}]}],"references":[{"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"}}}}