{"api_version":"1","generated_at":"2026-06-03T09:08:58+00:00","cve":"CVE-2026-46064","urls":{"html":"https://cve.report/CVE-2026-46064","api":"https://cve.report/api/cve/CVE-2026-46064.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-46064","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-46064"},"summary":{"title":"ibmasm: fix heap over-read in ibmasm_send_i2o_message()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nibmasm: fix heap over-read in ibmasm_send_i2o_message()\n\nThe ibmasm_send_i2o_message() function uses get_dot_command_size() to\ncompute the byte count for memcpy_toio(), but this value is derived from\nuser-controlled fields in the dot_command_header (command_size: u8,\ndata_size: u16) and is never validated against the actual allocation size.\nA root user can write a small buffer with inflated header fields, causing\nmemcpy_toio() to read up to ~65 KB past the end of the allocation into\nadjacent kernel heap, which is then forwarded to the service processor\nover MMIO.\n\nSilently clamping the copy size is not sufficient: if the header fields\nclaim a larger size than the buffer, the SP receives a dot command whose\nown header is inconsistent with the I2O message length, which can cause\nthe SP to desynchronize. Reject such commands outright by returning\nfailure.\n\nValidate command_size before calling get_mfa_inbound() to avoid leaking\nan I2O message frame: reading INBOUND_QUEUE_PORT dequeues a hardware\nframe from the controller's free pool, and returning without a\ncorresponding set_mfa_inbound() call would permanently exhaust it.\n\nAdditionally, clamp command_size to I2O_COMMAND_SIZE before the\nmemcpy_toio() so the MMIO write stays within the I2O message frame,\nconsistent with the clamping already performed by outgoing_message_size()\nfor the header field.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-05-27 14:17:26","updated_at":"2026-06-01 17:17:22"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/ce57fa439bd1b5d664f334a0c3e3f0e42abb0153","name":"https://git.kernel.org/stable/c/ce57fa439bd1b5d664f334a0c3e3f0e42abb0153","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/9e8f6c9d4ecddda2f28baa1678340286cff3969c","name":"https://git.kernel.org/stable/c/9e8f6c9d4ecddda2f28baa1678340286cff3969c","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/b870f652877bfbe321bd0f4096fc37a93296f7b6","name":"https://git.kernel.org/stable/c/b870f652877bfbe321bd0f4096fc37a93296f7b6","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/fd19eb1c75047a4ed4e855f56cafd704dc3914e0","name":"https://git.kernel.org/stable/c/fd19eb1c75047a4ed4e855f56cafd704dc3914e0","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/c1c2417c60dbdca5ebb00462f21ee71c2d7f7083","name":"https://git.kernel.org/stable/c/c1c2417c60dbdca5ebb00462f21ee71c2d7f7083","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/9aad71144fa3682cca3837a06c8623016790e7ec","name":"https://git.kernel.org/stable/c/9aad71144fa3682cca3837a06c8623016790e7ec","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/ca1c857e2bb74a9fc0606128334f85316d57067b","name":"https://git.kernel.org/stable/c/ca1c857e2bb74a9fc0606128334f85316d57067b","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/fe31722b0194ff76bf8b461e8bf97a2081147787","name":"https://git.kernel.org/stable/c/fe31722b0194ff76bf8b461e8bf97a2081147787","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-46064","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-46064","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 ca1c857e2bb74a9fc0606128334f85316d57067b git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 b870f652877bfbe321bd0f4096fc37a93296f7b6 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 ce57fa439bd1b5d664f334a0c3e3f0e42abb0153 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 fd19eb1c75047a4ed4e855f56cafd704dc3914e0 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 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semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.15.209 5.15.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.1.175 6.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6.140 6.6.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.86 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.27 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.0.4 7.0.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1-rc1 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"46064","cve":"CVE-2026-46064","epss":"0.000320000","percentile":"0.097530000","score_date":"2026-06-02","updated_at":"2026-06-03 00:08:16"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["drivers/misc/ibmasm/lowlevel.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"ca1c857e2bb74a9fc0606128334f85316d57067b","status":"affected","version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","versionType":"git"},{"lessThan":"b870f652877bfbe321bd0f4096fc37a93296f7b6","status":"affected","version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","versionType":"git"},{"lessThan":"ce57fa439bd1b5d664f334a0c3e3f0e42abb0153","status":"affected","version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","versionType":"git"},{"lessThan":"fd19eb1c75047a4ed4e855f56cafd704dc3914e0","status":"affected","version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","versionType":"git"},{"lessThan":"fe31722b0194ff76bf8b461e8bf97a2081147787","status":"affected","version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","versionType":"git"},{"lessThan":"c1c2417c60dbdca5ebb00462f21ee71c2d7f7083","status":"affected","version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","versionType":"git"},{"lessThan":"9e8f6c9d4ecddda2f28baa1678340286cff3969c","status":"affected","version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","versionType":"git"},{"lessThan":"9aad71144fa3682cca3837a06c8623016790e7ec","status":"affected","version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["drivers/misc/ibmasm/lowlevel.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"2.6.12"},{"lessThan":"2.6.12","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"5.10.*","status":"unaffected","version":"5.10.258","versionType":"semver"},{"lessThanOrEqual":"5.15.*","status":"unaffected","version":"5.15.209","versionType":"semver"},{"lessThanOrEqual":"6.1.*","status":"unaffected","version":"6.1.175","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.140","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.86","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.27","versionType":"semver"},{"lessThanOrEqual":"7.0.*","status":"unaffected","version":"7.0.4","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.1-rc1","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"5.10.258","versionStartIncluding":"2.6.12","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"5.15.209","versionStartIncluding":"2.6.12","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.1.175","versionStartIncluding":"2.6.12","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.140","versionStartIncluding":"2.6.12","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.86","versionStartIncluding":"2.6.12","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.27","versionStartIncluding":"2.6.12","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.0.4","versionStartIncluding":"2.6.12","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.1-rc1","versionStartIncluding":"2.6.12","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nibmasm: fix heap over-read in ibmasm_send_i2o_message()\n\nThe ibmasm_send_i2o_message() function uses get_dot_command_size() to\ncompute the byte count for memcpy_toio(), but this value is derived from\nuser-controlled fields in the dot_command_header (command_size: u8,\ndata_size: u16) and is never validated against the actual allocation size.\nA root user can write a small buffer with inflated header fields, causing\nmemcpy_toio() to read up to ~65 KB past the end of the allocation into\nadjacent kernel heap, which is then forwarded to the service processor\nover MMIO.\n\nSilently clamping the copy size is not sufficient: if the header fields\nclaim a larger size than the buffer, the SP receives a dot command whose\nown header is inconsistent with the I2O message length, which can cause\nthe SP to desynchronize. Reject such commands outright by returning\nfailure.\n\nValidate command_size before calling get_mfa_inbound() to avoid leaking\nan I2O message frame: reading INBOUND_QUEUE_PORT dequeues a hardware\nframe from the controller's free pool, and returning without a\ncorresponding set_mfa_inbound() call would permanently exhaust it.\n\nAdditionally, clamp command_size to I2O_COMMAND_SIZE before the\nmemcpy_toio() so the MMIO write stays within the I2O message frame,\nconsistent with the clamping already performed by outgoing_message_size()\nfor the header field."}],"providerMetadata":{"dateUpdated":"2026-06-01T16:17:53.396Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/ca1c857e2bb74a9fc0606128334f85316d57067b"},{"url":"https://git.kernel.org/stable/c/b870f652877bfbe321bd0f4096fc37a93296f7b6"},{"url":"https://git.kernel.org/stable/c/ce57fa439bd1b5d664f334a0c3e3f0e42abb0153"},{"url":"https://git.kernel.org/stable/c/fd19eb1c75047a4ed4e855f56cafd704dc3914e0"},{"url":"https://git.kernel.org/stable/c/fe31722b0194ff76bf8b461e8bf97a2081147787"},{"url":"https://git.kernel.org/stable/c/c1c2417c60dbdca5ebb00462f21ee71c2d7f7083"},{"url":"https://git.kernel.org/stable/c/9e8f6c9d4ecddda2f28baa1678340286cff3969c"},{"url":"https://git.kernel.org/stable/c/9aad71144fa3682cca3837a06c8623016790e7ec"}],"title":"ibmasm: fix heap over-read in ibmasm_send_i2o_message()","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-46064","datePublished":"2026-05-27T12:57:30.247Z","dateReserved":"2026-05-13T15:03:33.095Z","dateUpdated":"2026-06-01T16:17:53.396Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-05-27 14:17:26","lastModifiedDate":"2026-06-01 17:17:22","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"46064","Ordinal":"1","Title":"ibmasm: fix heap over-read in ibmasm_send_i2o_message()","CVE":"CVE-2026-46064","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"46064","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nibmasm: fix heap over-read in ibmasm_send_i2o_message()\n\nThe ibmasm_send_i2o_message() function uses get_dot_command_size() to\ncompute the byte count for memcpy_toio(), but this value is derived from\nuser-controlled fields in the dot_command_header (command_size: u8,\ndata_size: u16) and is never validated against the actual allocation size.\nA root user can write a small buffer with inflated header fields, causing\nmemcpy_toio() to read up to ~65 KB past the end of the allocation into\nadjacent kernel heap, which is then forwarded to the service processor\nover MMIO.\n\nSilently clamping the copy size is not sufficient: if the header fields\nclaim a larger size than the buffer, the SP receives a dot command whose\nown header is inconsistent with the I2O message length, which can cause\nthe SP to desynchronize. Reject such commands outright by returning\nfailure.\n\nValidate command_size before calling get_mfa_inbound() to avoid leaking\nan I2O message frame: reading INBOUND_QUEUE_PORT dequeues a hardware\nframe from the controller's free pool, and returning without a\ncorresponding set_mfa_inbound() call would permanently exhaust it.\n\nAdditionally, clamp command_size to I2O_COMMAND_SIZE before the\nmemcpy_toio() so the MMIO write stays within the I2O message frame,\nconsistent with the clamping already performed by outgoing_message_size()\nfor the header field.","Type":"Description","Title":"ibmasm: fix heap over-read in ibmasm_send_i2o_message()"}]}}}