{"id":"CVE-2026-64512","state":"PUBLISHED","title":"ACPI: CPPC: Suppress UBSAN warning caused by field misuse","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nACPI: CPPC: Suppress UBSAN warning caused by field misuse\n\nThe definition of reg->access_width changes depending on the\nreg->space_id type.  Type ACPI_ADR_SPACE_PLATFORM_COMM uses\naccess_width to indicate the PCC region, which can result in a UBSAN\nif the value is greater than 4.\n\nFor example:\n\n UBSAN: shift-out-of-bounds in drivers/acpi/cppc_acpi.c:1090:9\n shift exponent 32 is too large for 32-bit type 'int'\n CPU: 61 UID: 0 PID: 1220 Comm: (udev-worker) Not tainted 7.0.10-201.fc44.aarch64 #1 PREEMPT(lazy)\n Hardware name: To be filled by O.E.M.\n Call trace:\n  ...(trimming)\n  ubsan_epilogue+0x10/0x48\n  __ubsan_handle_shift_out_of_bounds+0xdc/0x1e0\n  cpc_write+0x4d0/0x670\n  cppc_set_perf+0x18c/0x490\n  cppc_cpufreq_cpu_init+0x1c8/0x380 [cppc_cpufreq]\n  ... (trimming)\n\nLets fix this by validating the region type, as well as whether\naccess_width has a value. Then since we are returning bit_width\ndirectly for ACPI_ADR_SPACE_PLATFORM_COMM, drop the code correcting\nthe size.","publishedAt":"2026-07-25T08:52:04.423Z","updatedAt":"2026-08-17T04:57:03.207Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"4949affd5288b867cdf115f5b08d6166b2027f87","status":"affected","lessThan":"b54c4632946ae42f2b39ed38abd909bbf78cbcc2","versionType":"git"},{"version":"01fc53be672acae37e611c80cc0b4f3939584de3","status":"affected","lessThan":"e904596ba6dd108534ffa15e3e46b2fe245145e2","versionType":"git"},{"version":"1b890ae474d19800a6be1696df7fb4d9a41676e4","status":"affected","lessThan":"2fb80e962029000959f651665baa4838cc92eb99","versionType":"git"},{"version":"2f4a4d63a193be6fd530d180bb13c3592052904c","status":"affected","lessThan":"37f28bf8f14672dfa395994e41fd778a63f0bf5c","versionType":"git"},{"version":"2f4a4d63a193be6fd530d180bb13c3592052904c","status":"affected","lessThan":"f29dc6132d4968e39d8fa575d1a12e2c718ce57b","versionType":"git"},{"version":"2f4a4d63a193be6fd530d180bb13c3592052904c","status":"affected","lessThan":"dc066bd13c860bb27d6ace511210e18b8064c1d9","versionType":"git"},{"version":"2f4a4d63a193be6fd530d180bb13c3592052904c","status":"affected","lessThan":"1b1acf2dada0cc3931bb2cb9ff8832edfbee46a1","versionType":"git"},{"version":"6cb6b12b78dcd8867a3fdbb1b6d0ed1df2b208d1","status":"affected","versionType":"git"},{"version":"5.15.154","status":"affected","lessThan":"5.15.155","versionType":"semver"},{"version":"6.1.90","status":"affected","lessThan":"6.1.178","versionType":"semver"},{"version":"6.6.30","status":"affected","lessThan":"6.6.145","versionType":"semver"},{"version":"6.8.9","status":"affected","lessThan":"6.9","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/acpi/cppc_acpi.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.9","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.9","versionType":"semver"},{"version":"5.15.155","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.178","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.145","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.96","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.39","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.4","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/acpi/cppc_acpi.c"]}],"references":["https://git.kernel.org/stable/c/b54c4632946ae42f2b39ed38abd909bbf78cbcc2","https://git.kernel.org/stable/c/e904596ba6dd108534ffa15e3e46b2fe245145e2","https://git.kernel.org/stable/c/2fb80e962029000959f651665baa4838cc92eb99","https://git.kernel.org/stable/c/37f28bf8f14672dfa395994e41fd778a63f0bf5c","https://git.kernel.org/stable/c/f29dc6132d4968e39d8fa575d1a12e2c718ce57b","https://git.kernel.org/stable/c/dc066bd13c860bb27d6ace511210e18b8064c1d9","https://git.kernel.org/stable/c/1b1acf2dada0cc3931bb2cb9ff8832edfbee46a1"],"weaknesses":[],"ingestedAt":"2026-10-29T20:12:41.951Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/64xxx/CVE-2026-64512.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-64512","state":"PUBLISHED","datePublished":"2026-07-25T08:52:04.423Z","dateUpdated":"2026-08-17T04:57:03.207Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-07-19T15:36:31.793Z"},"containers":{"cna":{"title":"ACPI: CPPC: Suppress UBSAN warning caused by field misuse","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nACPI: CPPC: Suppress UBSAN warning caused by field misuse\n\nThe definition of reg->access_width changes depending on the\nreg->space_id type.  Type ACPI_ADR_SPACE_PLATFORM_COMM uses\naccess_width to indicate the PCC region, which can result in a UBSAN\nif the value is greater than 4.\n\nFor example:\n\n UBSAN: shift-out-of-bounds in drivers/acpi/cppc_acpi.c:1090:9\n shift exponent 32 is too large for 32-bit type 'int'\n CPU: 61 UID: 0 PID: 1220 Comm: (udev-worker) Not tainted 7.0.10-201.fc44.aarch64 #1 PREEMPT(lazy)\n Hardware name: To be filled by O.E.M.\n Call trace:\n  ...(trimming)\n  ubsan_epilogue+0x10/0x48\n  __ubsan_handle_shift_out_of_bounds+0xdc/0x1e0\n  cpc_write+0x4d0/0x670\n  cppc_set_perf+0x18c/0x490\n  cppc_cpufreq_cpu_init+0x1c8/0x380 [cppc_cpufreq]\n  ... (trimming)\n\nLets fix this by validating the region type, as well as whether\naccess_width has a value. Then since we are returning bit_width\ndirectly for ACPI_ADR_SPACE_PLATFORM_COMM, drop the code correcting\nthe size."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"4949affd5288b867cdf115f5b08d6166b2027f87","status":"affected","lessThan":"b54c4632946ae42f2b39ed38abd909bbf78cbcc2","versionType":"git"},{"version":"01fc53be672acae37e611c80cc0b4f3939584de3","status":"affected","lessThan":"e904596ba6dd108534ffa15e3e46b2fe245145e2","versionType":"git"},{"version":"1b890ae474d19800a6be1696df7fb4d9a41676e4","status":"affected","lessThan":"2fb80e962029000959f651665baa4838cc92eb99","versionType":"git"},{"version":"2f4a4d63a193be6fd530d180bb13c3592052904c","status":"affected","lessThan":"37f28bf8f14672dfa395994e41fd778a63f0bf5c","versionType":"git"},{"version":"2f4a4d63a193be6fd530d180bb13c3592052904c","status":"affected","lessThan":"f29dc6132d4968e39d8fa575d1a12e2c718ce57b","versionType":"git"},{"version":"2f4a4d63a193be6fd530d180bb13c3592052904c","status":"affected","lessThan":"dc066bd13c860bb27d6ace511210e18b8064c1d9","versionType":"git"},{"version":"2f4a4d63a193be6fd530d180bb13c3592052904c","status":"affected","lessThan":"1b1acf2dada0cc3931bb2cb9ff8832edfbee46a1","versionType":"git"},{"version":"6cb6b12b78dcd8867a3fdbb1b6d0ed1df2b208d1","status":"affected","versionType":"git"},{"version":"5.15.154","status":"affected","lessThan":"5.15.155","versionType":"semver"},{"version":"6.1.90","status":"affected","lessThan":"6.1.178","versionType":"semver"},{"version":"6.6.30","status":"affected","lessThan":"6.6.145","versionType":"semver"},{"version":"6.8.9","status":"affected","lessThan":"6.9","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/acpi/cppc_acpi.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.9","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.9","versionType":"semver"},{"version":"5.15.155","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.178","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.145","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.96","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.39","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.4","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/acpi/cppc_acpi.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/b54c4632946ae42f2b39ed38abd909bbf78cbcc2"},{"url":"https://git.kernel.org/stable/c/e904596ba6dd108534ffa15e3e46b2fe245145e2"},{"url":"https://git.kernel.org/stable/c/2fb80e962029000959f651665baa4838cc92eb99"},{"url":"https://git.kernel.org/stable/c/37f28bf8f14672dfa395994e41fd778a63f0bf5c"},{"url":"https://git.kernel.org/stable/c/f29dc6132d4968e39d8fa575d1a12e2c718ce57b"},{"url":"https://git.kernel.org/stable/c/dc066bd13c860bb27d6ace511210e18b8064c1d9"},{"url":"https://git.kernel.org/stable/c/1b1acf2dada0cc3931bb2cb9ff8832edfbee46a1"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-17T04:57:03.207Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15.154","versionEndExcluding":"5.15.155"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.1.90","versionEndExcluding":"6.1.178"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.6.30","versionEndExcluding":"6.6.145"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.9","versionEndExcluding":"6.12.96"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.9","versionEndExcluding":"6.18.39"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.9","versionEndExcluding":"7.1.4"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.9","versionEndExcluding":"7.2"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.8.9"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}