From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C5330C432C3 for ; Thu, 4 Mar 2021 19:07:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AACBD64F60 for ; Thu, 4 Mar 2021 19:07:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237434AbhCDTHJ (ORCPT ); Thu, 4 Mar 2021 14:07:09 -0500 Received: from mail.kernel.org ([198.145.29.99]:38866 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236972AbhCDTGu (ORCPT ); Thu, 4 Mar 2021 14:06:50 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 0D47964F6B; Thu, 4 Mar 2021 19:06:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1614884770; bh=7LrZWfNLol5t2kvnpVyfLtni2s7+fi4sO40UtEpltH8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=X3QynV/GJPQswWurxr5/JAjmkjfcmhnYgq27jl4BHFJQmtXR7KQsmbP5b7JsOMr1o xHCpi2yCvl0+wpxFwBN46tOD9rAO08dJjy/vIyR+8HmEGEbgkxpN8PEb5CY8kTQaVy bBeahgurMMa4G/nedwjKP4pV61PAbXljmoOBcoVYrswh+BIrm7i9r1qCAk80GhOctC lyvEETN/+sfYeco38jPfAyY9E+31yA6YzJpm69DIs4Al7Ee9PCN6Uq9z8z+UJDi9B+ BYUO7iCrP0VQuMt+oI8eEtyyZ6+aD1tU6GORoWHKVDT3vAoKvWYluPw0FLB2jPr9+u WYBh7ibJHZ+yQ== From: Andy Lutomirski To: x86@kernel.org Cc: LKML , Mark Rutland , Andy Lutomirski Subject: [PATCH v3 03/11] x86/dumpstack: Remove unnecessary range check fetching opcode bytes Date: Thu, 4 Mar 2021 11:05:56 -0800 Message-Id: X-Mailer: git-send-email 2.29.2 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org copy_from_user_nmi() validates that the pointer is in the user range, so there is no need for an extra check in copy_code(). Signed-off-by: Andy Lutomirski --- arch/x86/kernel/dumpstack.c | 6 ------ 1 file changed, 6 deletions(-) diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c index 299c20f0a38b..55cf3c8325c6 100644 --- a/arch/x86/kernel/dumpstack.c +++ b/arch/x86/kernel/dumpstack.c @@ -81,12 +81,6 @@ static int copy_code(struct pt_regs *regs, u8 *buf, unsigned long src, /* The user space code from other tasks cannot be accessed. */ if (regs != task_pt_regs(current)) return -EPERM; - /* - * Make sure userspace isn't trying to trick us into dumping kernel - * memory by pointing the userspace instruction pointer at it. - */ - if (__chk_range_not_ok(src, nbytes, TASK_SIZE_MAX)) - return -EINVAL; /* * Even if named copy_from_user_nmi() this can be invoked from -- 2.29.2