From nobody Sat Feb 7 18:54:57 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A4009C04A95 for ; Sat, 22 Oct 2022 08:33:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230322AbiJVId0 (ORCPT ); Sat, 22 Oct 2022 04:33:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51926 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234148AbiJVI3r (ORCPT ); Sat, 22 Oct 2022 04:29:47 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BC6F524B334; Sat, 22 Oct 2022 01:02:00 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 6C012B82E19; Sat, 22 Oct 2022 07:47:03 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A6CFDC433C1; Sat, 22 Oct 2022 07:47:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1666424822; bh=DxdqHRq9n3CnM6oqOwqOVl6LE5qMcE9fhLL5nLUgjn8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=wn4SHrSmfkww5OWZr9F+TuB1FU0/HVOLfeM1jvhWXDJ7OONg+XCBhE3BqFcFDX9vM m30wTpPY3K+60rnT6jTTAg8lM9v/dyj0a7ey7czXGtCoxMP1nPpEo8/g3xjlpimNw3 gpU8g9Iy3d+SSnbI7MmXDyDYy7NsZF7wYL1HS8eA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Daniel Micay , Kees Cook , Borislav Petkov , Sasha Levin Subject: [PATCH 5.19 262/717] x86/microcode/AMD: Track patch allocation size explicitly Date: Sat, 22 Oct 2022 09:22:21 +0200 Message-Id: <20221022072500.994478851@linuxfoundation.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221022072415.034382448@linuxfoundation.org> References: <20221022072415.034382448@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Kees Cook [ Upstream commit 712f210a457d9c32414df246a72781550bc23ef6 ] In preparation for reducing the use of ksize(), record the actual allocation size for later memcpy(). This avoids copying extra (uninitialized!) bytes into the patch buffer when the requested allocation size isn't exactly the size of a kmalloc bucket. Additionally, fix potential future issues where runtime bounds checking will notice that the buffer was allocated to a smaller value than returned by ksize(). Fixes: 757885e94a22 ("x86, microcode, amd: Early microcode patch loading su= pport for AMD") Suggested-by: Daniel Micay Signed-off-by: Kees Cook Signed-off-by: Borislav Petkov Link: https://lore.kernel.org/lkml/CA+DvKQ+bp7Y7gmaVhacjv9uF6Ar-o4tet872h4Q= 8RPYPJjcJQA@mail.gmail.com/ Signed-off-by: Sasha Levin --- arch/x86/include/asm/microcode.h | 1 + arch/x86/kernel/cpu/microcode/amd.c | 3 ++- 2 files changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/x86/include/asm/microcode.h b/arch/x86/include/asm/microc= ode.h index 0c3d3440fe27..aa675783412f 100644 --- a/arch/x86/include/asm/microcode.h +++ b/arch/x86/include/asm/microcode.h @@ -9,6 +9,7 @@ struct ucode_patch { struct list_head plist; void *data; /* Intel uses only this one */ + unsigned int size; u32 patch_id; u16 equiv_cpu; }; diff --git a/arch/x86/kernel/cpu/microcode/amd.c b/arch/x86/kernel/cpu/micr= ocode/amd.c index 8b2fcdfa6d31..615bc6efa1dd 100644 --- a/arch/x86/kernel/cpu/microcode/amd.c +++ b/arch/x86/kernel/cpu/microcode/amd.c @@ -788,6 +788,7 @@ static int verify_and_add_patch(u8 family, u8 *fw, unsi= gned int leftover, kfree(patch); return -EINVAL; } + patch->size =3D *patch_size; =20 mc_hdr =3D (struct microcode_header_amd *)(fw + SECTION_HDR_SIZE); proc_id =3D mc_hdr->processor_rev_id; @@ -869,7 +870,7 @@ load_microcode_amd(bool save, u8 family, const u8 *data= , size_t size) return ret; =20 memset(amd_ucode_patch, 0, PATCH_MAX_SIZE); - memcpy(amd_ucode_patch, p->data, min_t(u32, ksize(p->data), PATCH_MAX_SIZ= E)); + memcpy(amd_ucode_patch, p->data, min_t(u32, p->size, PATCH_MAX_SIZE)); =20 return ret; } --=20 2.35.1