From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 7FE292236E5; Mon, 23 Jun 2025 21:55:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750715724; cv=none; b=ttdkp3rxqS7xiZb91cOWQrMbFL5fkyUO0CkWA3EenOIRWxWDH/EkRIWAeS3dADrfKvyDxz+VNJKbDCyPudz0xuB0qeHm2ZOUoSA9GETpWp64d7QeCmAt0wglPaNV7iRZz51UHj4AzhoB57njY91+NJ/eM/QpCwJPYnjAAP5XABM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750715724; c=relaxed/simple; bh=bx9iYJ1DyQSFgYK13BzJ3OYpWs7613CzdjnfpHZKEmE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=vD52KNTgAvM9zCkA79LEp2VDSEGMUaBZcj5qhRbFURl7ydUVKFtaw7j4dF9KWTW6nu00ZlpSHt79eefHbf06Gb23w4siz1aIJdc9JdwR7yXBiVHEmwIu1CbGhnA8f9wqrP5m2R/kpCH31GAaAPMziBrFI4QwgHhEELNMGKWZpJU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=hVlIzV3G; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="hVlIzV3G" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 17054C4CEED; Mon, 23 Jun 2025 21:55:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1750715724; bh=bx9iYJ1DyQSFgYK13BzJ3OYpWs7613CzdjnfpHZKEmE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hVlIzV3GcQA5VjJboptoWnwscMxgyTfaIuiInPBAyV/fIRWoanXI4TJWD0g3VbtIs /Jfqu9cfZJ9wGllUs7Ul/a4UD6JC97YVtBKIWbgkxKw4D/so9ftWou3HoVdq2UvY7w E8yGko6weLiBCzAaYDKPGbasPEGGMl5veHJzog+U= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Ahmed Salem , "Rafael J. Wysocki" , Sasha Levin Subject: [PATCH 5.15 263/411] ACPICA: Avoid sequence overread in call to strncmp() Date: Mon, 23 Jun 2025 15:06:47 +0200 Message-ID: <20250623130640.278480453@linuxfoundation.org> X-Mailer: git-send-email 2.50.0 In-Reply-To: <20250623130632.993849527@linuxfoundation.org> References: <20250623130632.993849527@linuxfoundation.org> User-Agent: quilt/0.68 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 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ahmed Salem [ Upstream commit 64b9dfd0776e9c38d733094859a09f13282ce6f8 ] ACPICA commit 8b83a8d88dfec59ea147fad35fc6deea8859c58c ap_get_table_length() checks if tables are valid by calling ap_is_valid_header(). The latter then calls ACPI_VALIDATE_RSDP_SIG(Table->Signature). ap_is_valid_header() accepts struct acpi_table_header as an argument, so the signature size is always fixed to 4 bytes. The problem is when the string comparison is between ACPI-defined table signature and ACPI_SIG_RSDP. Common ACPI table header specifies the Signature field to be 4 bytes long[1], with the exception of the RSDP structure whose signature is 8 bytes long "RSD PTR " (including the trailing blank character)[2]. Calling strncmp(sig, rsdp_sig, 8) would then result in a sequence overread[3] as sig would be smaller (4 bytes) than the specified bound (8 bytes). As a workaround, pass the bound conditionally based on the size of the signature being passed. Link: https://uefi.org/specs/ACPI/6.5_A/05_ACPI_Software_Programming_Model.html#system-description-table-header [1] Link: https://uefi.org/specs/ACPI/6.5_A/05_ACPI_Software_Programming_Model.html#root-system-description-pointer-rsdp-structure [2] Link: https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html#index-Wstringop-overread [3] Link: https://github.com/acpica/acpica/commit/8b83a8d8 Signed-off-by: Ahmed Salem Signed-off-by: Rafael J. Wysocki Link: https://patch.msgid.link/2248233.Mh6RI2rZIc@rjwysocki.net Signed-off-by: Sasha Levin --- include/acpi/actypes.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/acpi/actypes.h b/include/acpi/actypes.h index cefbb7ad253e0..ea50b9c469c9d 100644 --- a/include/acpi/actypes.h +++ b/include/acpi/actypes.h @@ -524,7 +524,7 @@ typedef u64 acpi_integer; /* Support for the special RSDP signature (8 characters) */ -#define ACPI_VALIDATE_RSDP_SIG(a) (!strncmp (ACPI_CAST_PTR (char, (a)), ACPI_SIG_RSDP, 8)) +#define ACPI_VALIDATE_RSDP_SIG(a) (!strncmp (ACPI_CAST_PTR (char, (a)), ACPI_SIG_RSDP, (sizeof(a) < 8) ? ACPI_NAMESEG_SIZE : 8)) #define ACPI_MAKE_RSDP_SIG(dest) (memcpy (ACPI_CAST_PTR (char, (dest)), ACPI_SIG_RSDP, 8)) /* Support for OEMx signature (x can be any character) */ -- 2.39.5