{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-46064","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-05-13T15:03:33.095Z","datePublished":"2026-05-27T12:57:30.247Z","dateUpdated":"2026-06-14T17:51:42.521Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-06-14T17:51:42.521Z"},"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."}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/misc/ibmasm/lowlevel.c"],"versions":[{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","lessThan":"ca1c857e2bb74a9fc0606128334f85316d57067b","status":"affected","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","lessThan":"b870f652877bfbe321bd0f4096fc37a93296f7b6","status":"affected","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","lessThan":"ce57fa439bd1b5d664f334a0c3e3f0e42abb0153","status":"affected","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","lessThan":"fd19eb1c75047a4ed4e855f56cafd704dc3914e0","status":"affected","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","lessThan":"fe31722b0194ff76bf8b461e8bf97a2081147787","status":"affected","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","lessThan":"c1c2417c60dbdca5ebb00462f21ee71c2d7f7083","status":"affected","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","lessThan":"9e8f6c9d4ecddda2f28baa1678340286cff3969c","status":"affected","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","lessThan":"9aad71144fa3682cca3837a06c8623016790e7ec","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/misc/ibmasm/lowlevel.c"],"versions":[{"version":"2.6.12","status":"affected"},{"version":"0","lessThan":"2.6.12","status":"unaffected","versionType":"semver"},{"version":"5.10.258","lessThanOrEqual":"5.10.*","status":"unaffected","versionType":"semver"},{"version":"5.15.209","lessThanOrEqual":"5.15.*","status":"unaffected","versionType":"semver"},{"version":"6.1.175","lessThanOrEqual":"6.1.*","status":"unaffected","versionType":"semver"},{"version":"6.6.140","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.86","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.27","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.0.4","lessThanOrEqual":"7.0.*","status":"unaffected","versionType":"semver"},{"version":"7.1","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":"2.6.12","versionEndExcluding":"5.10.258"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"5.15.209"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"6.1.175"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"6.6.140"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"6.12.86"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"6.18.27"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"7.0.4"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"7.1"}]}]}],"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"}}}}