CVE-2026-89533

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-89533", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.720Z", "datePublished": "2026-09-11T19:44:12.236Z", "dateUpdated": "2026-10-19T08:48:24.875Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T08:48:24.875Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsvcrdma: Fix offset arithmetic in read_chunk_range\n\nsvc_rdma_read_chunk_range() walks a Read chunk's segment list to\nbuild a sub-range starting at byte offset and spanning length bytes\nfor a Position-Zero or Call chunk. Two arithmetic defects in the\nper-segment loop produce wrong DMA lengths and a u32 underflow:\n\n pcl_for_each_segment(segment, chunk) {\n if (offset > segment->rs_length) {\n offset -= segment->rs_length;\n continue;\n }\n\n dummy.rs_handle = segment->rs_handle;\n dummy.rs_length = min_t(u32, length,\n segment->rs_length) - offset;\n dummy.rs_offset = segment->rs_offset + offset;\n\nFirst, the skip predicate uses '>' instead of '>='. When offset\nequals the segment's full rs_length, the segment is fully consumed\nand should be skipped, but the loop falls through into the body.\nThe resulting dummy.rs_length is min_t(u32, length, rs_length) -\nrs_length, which underflows to a near-UINT_MAX u32 when length is\nsmaller than rs_length, or is zero otherwise.\n\nSecond, the length formula subtracts offset from the min_t() result\nrather than from segment->rs_length before the cap. For offset > 0\nthe segment's residual is rs_length - offset, not rs_length, so the\ncap must be applied to the residual. With the current bracketing,\nwhenever length is smaller than rs_length - offset the per-segment\nlength becomes length - offset instead of length, silently dropping\noffset bytes from the rebuilt chunk. Combined with the boundary\ncase above it also enables the u32 underflow path, which propagates\na huge nr_bvec into svc_rdma_build_read_segment() and a multi-MiB\nkmalloc_array_node() in svc_rdma_get_rw_ctxt().\n\nAdditionally, svc_rdma_read_call_chunk() can invoke this function\nwith length == 0 when the last Read chunk ends exactly at the end\nof the Call chunk. With the corrected >= predicate, every segment\nis skipped and the function returns the initial -EINVAL, rejecting\na valid request. Return success immediately when length is zero.\nAlso break out of the loop once length is fully consumed to avoid\npassing zero-length segments to svc_rdma_build_read_segment().\n\nFix by using '>=' so a fully-consumed segment is skipped, by\nmoving '- offset' inside min_t() so the cap is applied to the\nsegment's residual length, by returning success for zero-length\nrequests, and by stopping iteration when the requested range has\nbeen consumed."}], "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 server transport; a remote peer reaches svc_rdma_read_chunk_range() by sending a Call with a Position-Zero/Call chunk and Read list over routable iWARP or RoCEv2, matching prior kernel CNA scores for this subsystem.\nAC:L - The attacker fully controls Call-chunk segment lengths and Read-chunk positions and can place a Read chunk on a segment boundary with a smaller remaining range so dummy.rs_length underflows a u32 deterministically, with no race or uncontrollable layout.\nPR:N - svc_rdma_process_read_list() runs 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 Call chunk and Read list to an already-listening NFS/RDMA service is sufficient; no victim mount, click, or other user action is required.\nS:U - The vulnerable NFS/RDMA service and affected kernel memory belong to the same host kernel security authority; this is not a VM, IOMMU, or sandbox escape.\nC:H - The underflowed length is added to rc_readbytes and, when Reads complete, svc_rdma_read_complete_pzrc() sets xdr_buf.page_len to a near-4GiB value, so XDR walks far past the rq_pages allocation and reads adjacent kernel heap as page pointers.\nI:H - XDR helpers such as xdr_buf_pages_zero() kmap and memset through that inflated page_len, writing via out-of-bounds page pointers taken from adjacent slab, a kernel integrity and control-flow hijack primitive.\nA:H - On the scatterlist path PAGE_ALIGN wrapping to 0 hits sg_alloc_table_chained(0) which BUG_ON(!nents) and panics; the huge page_len walk oopses on invalid pages, and an unauthenticated peer can repeat this per request."}]}], "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": "d7cc73972661be4a02a1b09f1d9b3283c6c05154", "lessThan": "10873311f91db9454e2fadbf9866bc819e0646d9", "status": "affected", "versionType": "git"}, {"version": "d7cc73972661be4a02a1b09f1d9b3283c6c05154", "lessThan": "addbf02dfe3b25e7e38e03bbd4e2a6ed86a14be7", "status": "affected", "versionType": "git"}, {"version": "d7cc73972661be4a02a1b09f1d9b3283c6c05154", "lessThan": "cba8543c18cf42fd80fd63effb6df6ff4f7e73ce", "status": "affected", "versionType": "git"}, {"version": "d7cc73972661be4a02a1b09f1d9b3283c6c05154", "lessThan": "6ee4dc7476b3abc92ec1d444533a559f33f59561", "status": "affected", "versionType": "git"}, {"version": "d7cc73972661be4a02a1b09f1d9b3283c6c05154", "lessThan": "a46b35f213c2426f5d6a0458a8f7e873fc59cdfd", "status": "affected", "versionType": "git"}, {"version": "d7cc73972661be4a02a1b09f1d9b3283c6c05154", "lessThan": "4493c96bbd0068fadf69cbae8d13426202e34cdc", "status": "affected", "versionType": "git"}, {"version": "d7cc73972661be4a02a1b09f1d9b3283c6c05154", "lessThan": "4a44c140cc2f3643a39e258bb0c0ab9d0f494f5e", "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": "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": "6.12.109", "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": "5.15.221"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.11", "versionEndExcluding": "6.1.188"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.11", "versionEndExcluding": "6.6.157"}, {"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/10873311f91db9454e2fadbf9866bc819e0646d9"}, {"url": "https://git.kernel.org/stable/c/addbf02dfe3b25e7e38e03bbd4e2a6ed86a14be7"}, {"url": "https://git.kernel.org/stable/c/cba8543c18cf42fd80fd63effb6df6ff4f7e73ce"}, {"url": "https://git.kernel.org/stable/c/6ee4dc7476b3abc92ec1d444533a559f33f59561"}, {"url": "https://git.kernel.org/stable/c/a46b35f213c2426f5d6a0458a8f7e873fc59cdfd"}, {"url": "https://git.kernel.org/stable/c/4493c96bbd0068fadf69cbae8d13426202e34cdc"}, {"url": "https://git.kernel.org/stable/c/4a44c140cc2f3643a39e258bb0c0ab9d0f494f5e"}], "title": "svcrdma: Fix offset arithmetic in read_chunk_range", "x_generator": {"engine": "bippy-1.2.0"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-89533", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "yes"}, {"Technical Impact": "total"}], "version": "2.0.3", "timestamp": "2026-10-16T19:23:13.656876Z"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-16T19:26:41.551Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-89533", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "yes"}, {"Technical Impact": "total"}], "version": "2.0.3", "timestamp": "2026-10-16T19:23:13.656876Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-16T19:23:14.222Z"}}], "cna": {"title": "svcrdma: Fix offset arithmetic in read_chunk_range", "metrics": [{"cvssV3_1": {"version": "3.1", "baseScore": 9.8, "baseSeverity": "CRITICAL", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"}, "scenarios": [{"lang": "en", "value": "AV:N - svcrdma is nfsd's RPC-over-RDMA server transport; a remote peer reaches svc_rdma_read_chunk_range() by sending a Call with a Position-Zero/Call chunk and Read list over routable iWARP or RoCEv2, matching prior kernel CNA scores for this subsystem.\nAC:L - The attacker fully controls Call-chunk segment lengths and Read-chunk positions and can place a Read chunk on a segment boundary with a smaller remaining range so dummy.rs_length underflows a u32 deterministically, with no race or uncontrollable layout.\nPR:N - svc_rdma_process_read_list() runs 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 Call chunk and Read list to an already-listening NFS/RDMA service is sufficient; no victim mount, click, or other user action is required.\nS:U - The vulnerable NFS/RDMA service and affected kernel memory belong to the same host kernel security authority; this is not a VM, IOMMU, or sandbox escape.\nC:H - The underflowed length is added to rc_readbytes and, when Reads complete, svc_rdma_read_complete_pzrc() sets xdr_buf.page_len to a near-4GiB value, so XDR walks far past the rq_pages allocation and reads adjacent kernel heap as page pointers.\nI:H - XDR helpers such as xdr_buf_pages_zero() kmap and memset through that inflated page_len, writing via out-of-bounds page pointers taken from adjacent slab, a kernel integrity and control-flow hijack primitive.\nA:H - On the scatterlist path PAGE_ALIGN wrapping to 0 hits sg_alloc_table_chained(0) which BUG_ON(!nents) and panics; the huge page_len walk oopses on invalid pages, and an unauthenticated peer can repeat this per request."}]}], "affected": [{"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "d7cc73972661be4a02a1b09f1d9b3283c6c05154", "lessThan": "10873311f91db9454e2fadbf9866bc819e0646d9", "versionType": "git"}, {"status": "affected", "version": "d7cc73972661be4a02a1b09f1d9b3283c6c05154", "lessThan": "addbf02dfe3b25e7e38e03bbd4e2a6ed86a14be7", "versionType": "git"}, {"status": "affected", "version": "d7cc73972661be4a02a1b09f1d9b3283c6c05154", "lessThan": "cba8543c18cf42fd80fd63effb6df6ff4f7e73ce", "versionType": "git"}, {"status": "affected", "version": "d7cc73972661be4a02a1b09f1d9b3283c6c05154", "lessThan": "6ee4dc7476b3abc92ec1d444533a559f33f59561", "versionType": "git"}, {"status": "affected", "version": "d7cc73972661be4a02a1b09f1d9b3283c6c05154", "lessThan": "a46b35f213c2426f5d6a0458a8f7e873fc59cdfd", "versionType": "git"}, {"status": "affected", "version": "d7cc73972661be4a02a1b09f1d9b3283c6c05154", "lessThan": "4493c96bbd0068fadf69cbae8d13426202e34cdc", "versionType": "git"}, {"status": "affected", "version": "d7cc73972661be4a02a1b09f1d9b3283c6c05154", "lessThan": "4a44c140cc2f3643a39e258bb0c0ab9d0f494f5e", "versionType": "git"}], "programFiles": ["net/sunrpc/xprtrdma/svc_rdma_rw.c"], "defaultStatus": "unaffected"}, {"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "5.11"}, {"status": "unaffected", "version": "0", "lessThan": "5.11", "versionType": "semver"}, {"status": "unaffected", "version": "5.15.221", "versionType": "semver", "lessThanOrEqual": "5.15.*"}, {"status": "unaffected", "version": "6.1.188", "versionType": "semver", "lessThanOrEqual": "6.1.*"}, {"status": "unaffected", "version": "6.6.157", "versionType": "semver", "lessThanOrEqual": "6.6.*"}, {"status": "unaffected", "version": "6.12.109", "versionType": "semver", "lessThanOrEqual": "6.12.*"}, {"status": "unaffected", "version": "6.18.50", "versionType": "semver", "lessThanOrEqual": "6.18.*"}, {"status": "unaffected", "version": "7.2.4", "versionType": "semver", "lessThanOrEqual": "7.2.*"}, {"status": "unaffected", "version": "7.3", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*"}], "programFiles": ["net/sunrpc/xprtrdma/svc_rdma_rw.c"], "defaultStatus": "affected"}], "references": [{"url": "https://git.kernel.org/stable/c/10873311f91db9454e2fadbf9866bc819e0646d9"}, {"url": "https://git.kernel.org/stable/c/addbf02dfe3b25e7e38e03bbd4e2a6ed86a14be7"}, {"url": "https://git.kernel.org/stable/c/cba8543c18cf42fd80fd63effb6df6ff4f7e73ce"}, {"url": "https://git.kernel.org/stable/c/6ee4dc7476b3abc92ec1d444533a559f33f59561"}, {"url": "https://git.kernel.org/stable/c/a46b35f213c2426f5d6a0458a8f7e873fc59cdfd"}, {"url": "https://git.kernel.org/stable/c/4493c96bbd0068fadf69cbae8d13426202e34cdc"}, {"url": "https://git.kernel.org/stable/c/4a44c140cc2f3643a39e258bb0c0ab9d0f494f5e"}], "x_generator": {"engine": "bippy-1.2.0"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsvcrdma: Fix offset arithmetic in read_chunk_range\n\nsvc_rdma_read_chunk_range() walks a Read chunk's segment list to\nbuild a sub-range starting at byte offset and spanning length bytes\nfor a Position-Zero or Call chunk. Two arithmetic defects in the\nper-segment loop produce wrong DMA lengths and a u32 underflow:\n\n pcl_for_each_segment(segment, chunk) {\n if (offset > segment->rs_length) {\n offset -= segment->rs_length;\n continue;\n }\n\n dummy.rs_handle = segment->rs_handle;\n dummy.rs_length = min_t(u32, length,\n segment->rs_length) - offset;\n dummy.rs_offset = segment->rs_offset + offset;\n\nFirst, the skip predicate uses '>' instead of '>='. When offset\nequals the segment's full rs_length, the segment is fully consumed\nand should be skipped, but the loop falls through into the body.\nThe resulting dummy.rs_length is min_t(u32, length, rs_length) -\nrs_length, which underflows to a near-UINT_MAX u32 when length is\nsmaller than rs_length, or is zero otherwise.\n\nSecond, the length formula subtracts offset from the min_t() result\nrather than from segment->rs_length before the cap. For offset > 0\nthe segment's residual is rs_length - offset, not rs_length, so the\ncap must be applied to the residual. With the current bracketing,\nwhenever length is smaller than rs_length - offset the per-segment\nlength becomes length - offset instead of length, silently dropping\noffset bytes from the rebuilt chunk. Combined with the boundary\ncase above it also enables the u32 underflow path, which propagates\na huge nr_bvec into svc_rdma_build_read_segment() and a multi-MiB\nkmalloc_array_node() in svc_rdma_get_rw_ctxt().\n\nAdditionally, svc_rdma_read_call_chunk() can invoke this function\nwith length == 0 when the last Read chunk ends exactly at the end\nof the Call chunk. With the corrected >= predicate, every segment\nis skipped and the function returns the initial -EINVAL, rejecting\na valid request. Return success immediately when length is zero.\nAlso break out of the loop once length is fully consumed to avoid\npassing zero-length segments to svc_rdma_build_read_segment().\n\nFix by using '>=' so a fully-consumed segment is skipped, by\nmoving '- offset' inside min_t() so the cap is applied to the\nsegment's residual length, by returning success for zero-length\nrequests, and by stopping iteration when the requested range has\nbeen consumed."}], "cpeApplicability": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "5.15.221", "versionStartIncluding": "5.11"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.1.188", "versionStartIncluding": "5.11"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.6.157", "versionStartIncluding": "5.11"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.12.109", "versionStartIncluding": "5.11"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.18.50", "versionStartIncluding": "5.11"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "7.2.4", "versionStartIncluding": "5.11"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "7.3", "versionStartIncluding": "5.11"}], "operator": "OR"}]}], "providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T08:48:24.875Z"}}}, "cveMetadata": {"cveId": "CVE-2026-89533", "state": "PUBLISHED", "dateUpdated": "2026-10-19T08:48:24.875Z", "dateReserved": "2026-09-11T19:38:34.720Z", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "datePublished": "2026-09-11T19:44:12.236Z", "assignerShortName": "Linux"}, "dataVersion": "5.2"}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["net/sunrpc/xprtrdma/svc_rdma_rw.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "10873311f91db9454e2fadbf9866bc819e0646d9", "status": "affected", "version": "d7cc73972661be4a02a1b09f1d9b3283c6c05154", "versionType": "git"}, {"lessThan": "addbf02dfe3b25e7e38e03bbd4e2a6ed86a14be7", "status": "affected", "version": "d7cc73972661be4a02a1b09f1d9b3283c6c05154", "versionType": "git"}, {"lessThan": "cba8543c18cf42fd80fd63effb6df6ff4f7e73ce", "status": "affected", "version": "d7cc73972661be4a02a1b09f1d9b3283c6c05154", "versionType": "git"}, {"lessThan": "6ee4dc7476b3abc92ec1d444533a559f33f59561", "status": "affected", "version": "d7cc73972661be4a02a1b09f1d9b3283c6c05154", "versionType": "git"}, {"lessThan": "a46b35f213c2426f5d6a0458a8f7e873fc59cdfd", "status": "affected", "version": "d7cc73972661be4a02a1b09f1d9b3283c6c05154", "versionType": "git"}, {"lessThan": "4493c96bbd0068fadf69cbae8d13426202e34cdc", "status": "affected", "version": "d7cc73972661be4a02a1b09f1d9b3283c6c05154", "versionType": "git"}, {"lessThan": "4a44c140cc2f3643a39e258bb0c0ab9d0f494f5e", "status": "affected", "version": "d7cc73972661be4a02a1b09f1d9b3283c6c05154", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["net/sunrpc/xprtrdma/svc_rdma_rw.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "5.11"}, {"lessThan": "5.11", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "5.15.*", "status": "unaffected", "version": "5.15.221", "versionType": "semver"}, {"lessThanOrEqual": "6.1.*", "status": "unaffected", "version": "6.1.188", "versionType": "semver"}, {"lessThanOrEqual": "6.6.*", "status": "unaffected", "version": "6.6.157", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.109", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.50", "versionType": "semver"}, {"lessThanOrEqual": "7.2.*", "status": "unaffected", "version": "7.2.4", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.3", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsvcrdma: Fix offset arithmetic in read_chunk_range\n\nsvc_rdma_read_chunk_range() walks a Read chunk's segment list to\nbuild a sub-range starting at byte offset and spanning length bytes\nfor a Position-Zero or Call chunk. Two arithmetic defects in the\nper-segment loop produce wrong DMA lengths and a u32 underflow:\n\n pcl_for_each_segment(segment, chunk) {\n if (offset > segment->rs_length) {\n offset -= segment->rs_length;\n continue;\n }\n\n dummy.rs_handle = segment->rs_handle;\n dummy.rs_length = min_t(u32, length,\n segment->rs_length) - offset;\n dummy.rs_offset = segment->rs_offset + offset;\n\nFirst, the skip predicate uses '>' instead of '>='. When offset\nequals the segment's full rs_length, the segment is fully consumed\nand should be skipped, but the loop falls through into the body.\nThe resulting dummy.rs_length is min_t(u32, length, rs_length) -\nrs_length, which underflows to a near-UINT_MAX u32 when length is\nsmaller than rs_length, or is zero otherwise.\n\nSecond, the length formula subtracts offset from the min_t() result\nrather than from segment->rs_length before the cap. For offset > 0\nthe segment's residual is rs_length - offset, not rs_length, so the\ncap must be applied to the residual. With the current bracketing,\nwhenever length is smaller than rs_length - offset the per-segment\nlength becomes length - offset instead of length, silently dropping\noffset bytes from the rebuilt chunk. Combined with the boundary\ncase above it also enables the u32 underflow path, which propagates\na huge nr_bvec into svc_rdma_build_read_segment() and a multi-MiB\nkmalloc_array_node() in svc_rdma_get_rw_ctxt().\n\nAdditionally, svc_rdma_read_call_chunk() can invoke this function\nwith length == 0 when the last Read chunk ends exactly at the end\nof the Call chunk. With the corrected >= predicate, every segment\nis skipped and the function returns the initial -EINVAL, rejecting\na valid request. Return success immediately when length is zero.\nAlso break out of the loop once length is fully consumed to avoid\npassing zero-length segments to svc_rdma_build_read_segment().\n\nFix by using '>=' so a fully-consumed segment is skipped, by\nmoving '- offset' inside min_t() so the cap is applied to the\nsegment's residual length, by returning success for zero-length\nrequests, and by stopping iteration when the requested range has\nbeen consumed."}], "id": "CVE-2026-89533", "lastModified": "2026-10-19T09:17:47.923", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 9.8, "baseSeverity": "CRITICAL", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 5.9, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-89533", "options": [{"exploitation": "none"}, {"automatable": "yes"}, {"technicalImpact": "total"}], "role": "CISA Coordinator", "timestamp": "2026-10-16T19:23:13.656876Z", "version": "2.0.3"}}]}, "published": "2026-09-11T20:19:36.250", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/10873311f91db9454e2fadbf9866bc819e0646d9"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/4493c96bbd0068fadf69cbae8d13426202e34cdc"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/4a44c140cc2f3643a39e258bb0c0ab9d0f494f5e"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/6ee4dc7476b3abc92ec1d444533a559f33f59561"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/a46b35f213c2426f5d6a0458a8f7e873fc59cdfd"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/addbf02dfe3b25e7e38e03bbd4e2a6ed86a14be7"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/cba8543c18cf42fd80fd63effb6df6ff4f7e73ce"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: Linux kernel: svcrdma Denial of Service due to incorrect offset arithmetic", "id": "2532058", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2532058"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.9", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-191", "details": ["A flaw was found in the `svcrdma` component of the Linux kernel. Incorrect offset arithmetic in the `svc_rdma_read_chunk_range()` function can lead to a `u32` underflow. This underflow can cause the system to attempt to allocate a large amount of memory, potentially resulting in a Denial of Service (DoS) due to excessive memory consumption."], "name": "CVE-2026-89533", "package_state": [{"cpe": "cpe:/a:redhat:openshift:4", "fix_state": "Affected", "package_name": "openshift/ose-rhel-coreos-8", "product_name": "Red Hat OpenShift Container Platform 4"}, {"cpe": "cpe:/a:redhat:openshift:4", "fix_state": "Affected", "package_name": "openshift/ose-rhel-coreos-9", "product_name": "Red Hat OpenShift Container Platform 4"}], "public_date": "2026-09-11T19:44:12Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-89533\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-89533\nhttps://git.kernel.org/stable/c/4493c96bbd0068fadf69cbae8d13426202e34cdc\nhttps://git.kernel.org/stable/c/4a44c140cc2f3643a39e258bb0c0ab9d0f494f5e\nhttps://git.kernel.org/stable/c/6ee4dc7476b3abc92ec1d444533a559f33f59561\nhttps://git.kernel.org/stable/c/a46b35f213c2426f5d6a0458a8f7e873fc59cdfd"], "threat_severity": "Important"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[d7cc73972661be4a02a1b09f1d9b3283c6c05154,6ee4dc7476b3abc92ec1d444533a559f33f59561)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[d7cc73972661be4a02a1b09f1d9b3283c6c05154,a46b35f213c2426f5d6a0458a8f7e873fc59cdfd)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[d7cc73972661be4a02a1b09f1d9b3283c6c05154,4493c96bbd0068fadf69cbae8d13426202e34cdc)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[d7cc73972661be4a02a1b09f1d9b3283c6c05154,4a44c140cc2f3643a39e258bb0c0ab9d0f494f5e)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "5.11"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[0,5.11)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.12.109,6.13.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.50,6.19.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.2.4,7.3.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.3-rc1,*]"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "created": "2026-09-12T07:15:10.615362+00:00", "updated": "2026-09-21T01:30:08.749342+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}