From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1A2073B0ADE; Thu, 16 Jul 2026 14:21:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784211670; cv=none; b=Bo3LkmqiUHCQGCb5Ngb5x7hsJnXkXyGhL+6dfHPAfSS+qHMX3B6C7zBnzbA1IOr9ksfl5OIPMa+8HeI0kXuKeAqSMIeHgMWLUO1lNjevLKnG9aANg++NoiI1UXWggSVEH58qpGDpPCFCUsch3t9e4pdR4/Zh+0I/sWJ9IyGRDo8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784211670; c=relaxed/simple; bh=zwVL/1AHjrOwhte6SxnIajCy0dSVM02o0IEw6n7Ew7M=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=R2WndtU9xdOVURwie8ZPvg/ahDOQInD1K4GrXPyEyE6sLewaIKI2fd0do3DBKO5yqRu3ukAsrh8JMK6fYTuUdnGO/iON1SxohCe7soRfVOH2zUf31WU/LWCt+tui8g+TbWV9wvEqJ3r6rSxN5CNczyV1ryd6cYQ/CeeRDfTQDJw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=ShuX0mmX; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="ShuX0mmX" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 80EC61F000E9; Thu, 16 Jul 2026 14:21:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784211669; bh=mUI6h6lUBf87JpxLzwG2adgefXw6BdzTzirX/KYt8Qo=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=ShuX0mmXLTacAIR7di6fmPUevgi+oJ9brJbIZ+8NBGITPDxELi18b6uEZvQQ8gH04 jzJ41zdc7/PwyYLsTAmzM9sRFFnT8piKHXuAOyuMIehxKBq2O9uPIv++Xfigl2iewD gHWG4rL0f7H5KkePsvx/kkmylX7IgWzvdaa2CdK4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jeremy Linton , Jarred White , Easwar Hariharan , "Rafael J. Wysocki" Subject: [PATCH 6.12 034/349] ACPI: CPPC: Suppress UBSAN warning caused by field misuse Date: Thu, 16 Jul 2026 15:29:28 +0200 Message-ID: <20260716133034.073858585@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260716133033.287196923@linuxfoundation.org> References: <20260716133033.287196923@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jeremy Linton commit 1b1acf2dada0cc3931bb2cb9ff8832edfbee46a1 upstream. 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. Fixes: 2f4a4d63a193 ("ACPI: CPPC: Use access_width over bit_width for system memory accesses") Signed-off-by: Jeremy Linton Tested-by: Jarred White Reviewed-by: Jarred White Reviewed-by: Easwar Hariharan Cc: All applicable Link: https://patch.msgid.link/20260601235808.1113137-1-jeremy.linton@arm.com Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman --- drivers/acpi/cppc_acpi.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) --- a/drivers/acpi/cppc_acpi.c +++ b/drivers/acpi/cppc_acpi.c @@ -172,8 +172,13 @@ show_cppc_data(cppc_get_perf_caps, cppc_ show_cppc_data(cppc_get_perf_ctrs, cppc_perf_fb_ctrs, reference_perf); show_cppc_data(cppc_get_perf_ctrs, cppc_perf_fb_ctrs, wraparound_time); -/* Check for valid access_width, otherwise, fallback to using bit_width */ -#define GET_BIT_WIDTH(reg) ((reg)->access_width ? (8 << ((reg)->access_width - 1)) : (reg)->bit_width) +/* + * PCC reuses the access_width field as the subspace id, so only decode access + * size for non-PCC registers. Otherwise, use the bit_width. + */ +#define GET_BIT_WIDTH(reg) (((reg)->access_width && \ + (reg)->space_id != ACPI_ADR_SPACE_PLATFORM_COMM) ? \ + (8 << ((reg)->access_width - 1)) : (reg)->bit_width) /* Shift and apply the mask for CPC reads/writes */ #define MASK_VAL_READ(reg, val) (((val) >> (reg)->bit_offset) & \ @@ -1031,7 +1036,6 @@ static int cpc_read(int cpu, struct cpc_ * by the bit width field; the access size is used to indicate * the PCC subspace id. */ - size = reg->bit_width; vaddr = GET_PCC_VADDR(reg->address, pcc_ss_id); } else if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) @@ -1103,7 +1107,6 @@ static int cpc_write(int cpu, struct cpc * by the bit width field; the access size is used to indicate * the PCC subspace id. */ - size = reg->bit_width; vaddr = GET_PCC_VADDR(reg->address, pcc_ss_id); } else if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY)