GHSA-GQX5-8446-4X25
Vulnerability from github – Published: 2026-07-25 12:31 – Updated: 2026-07-25 12:31In the Linux kernel, the following vulnerability has been resolved:
ACPI: CPPC: Suppress UBSAN warning caused by field misuse
The definition of reg->access_width changes depending on the reg->space_id type. Type ACPI_ADR_SPACE_PLATFORM_COMM uses access_width to indicate the PCC region, which can result in a UBSAN if the value is greater than 4.
For example:
UBSAN: shift-out-of-bounds in drivers/acpi/cppc_acpi.c:1090:9 shift exponent 32 is too large for 32-bit type 'int' CPU: 61 UID: 0 PID: 1220 Comm: (udev-worker) Not tainted 7.0.10-201.fc44.aarch64 #1 PREEMPT(lazy) Hardware name: To be filled by O.E.M. Call trace: ...(trimming) ubsan_epilogue+0x10/0x48 __ubsan_handle_shift_out_of_bounds+0xdc/0x1e0 cpc_write+0x4d0/0x670 cppc_set_perf+0x18c/0x490 cppc_cpufreq_cpu_init+0x1c8/0x380 [cppc_cpufreq] ... (trimming)
Lets fix this by validating the region type, as well as whether access_width has a value. Then since we are returning bit_width directly for ACPI_ADR_SPACE_PLATFORM_COMM, drop the code correcting the size.
{
"affected": [],
"aliases": [
"CVE-2026-64512"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-07-25T10:17:37Z",
"severity": null
},
"details": "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-\u003eaccess_width changes depending on the\nreg-\u003espace_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 \u0027int\u0027\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.",
"id": "GHSA-gqx5-8446-4x25",
"modified": "2026-07-25T12:31:38Z",
"published": "2026-07-25T12:31:38Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-64512"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/1b1acf2dada0cc3931bb2cb9ff8832edfbee46a1"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/2fb80e962029000959f651665baa4838cc92eb99"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/37f28bf8f14672dfa395994e41fd778a63f0bf5c"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/b54c4632946ae42f2b39ed38abd909bbf78cbcc2"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/dc066bd13c860bb27d6ace511210e18b8064c1d9"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/e904596ba6dd108534ffa15e3e46b2fe245145e2"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/f29dc6132d4968e39d8fa575d1a12e2c718ce57b"
}
],
"schema_version": "1.4.0",
"severity": []
}
Sightings
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