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=-13.1 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 87D7CC433DF for ; Mon, 27 Jul 2020 21:38:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4578020809 for ; Mon, 27 Jul 2020 21:38:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="IcQwbCob" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726313AbgG0Vir (ORCPT ); Mon, 27 Jul 2020 17:38:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48958 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726110AbgG0Viq (ORCPT ); Mon, 27 Jul 2020 17:38:46 -0400 Received: from mail-qv1-xf43.google.com (mail-qv1-xf43.google.com [IPv6:2607:f8b0:4864:20::f43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5A49FC061794 for ; Mon, 27 Jul 2020 14:38:46 -0700 (PDT) Received: by mail-qv1-xf43.google.com with SMTP id m9so8219631qvx.5 for ; Mon, 27 Jul 2020 14:38:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=OBPW13q5QlzlSrMzZgbTLPGHsSTa3HJ7NZm2XA+DWro=; b=IcQwbCobh7vNkJkcr8tb+vx7W74HheX2L8Fr7dpZ/em+hbTwhHjTLmVR+cPsFn6OsS gPOStCmf9ky3UPVmE+InLyxIWDCcHAS77jlOJpw0ym4EqJyydFZ8mDhkIIfnsBfVTLMK USUO2V1Pn8scghR4r3f87qt6DArxNQxzZd/Dlu0LiMs7L1FQR4Q8or8lgs7hH0e4qzS7 7QK0AhL4agBclZPMj6pGcJLOYAV9Ru8R4+qRTdJHOYEj5JExzL9ACW2pXGvB2C/F4u+t LksyLeCqSowFyLoejfb9YdEZFCQLPt7IMNUxVKhgdiI2FP27N8A3XU5tPFjxdUTwadTU rx+Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=OBPW13q5QlzlSrMzZgbTLPGHsSTa3HJ7NZm2XA+DWro=; b=Dcg8TZmk+27XGnZU7aM4VM1QXWYvShXbjMm7x2qdxORTEHbD31RI2V74Kw1m+H1E0E 8C9eYvjvTasB22scRzcq11/UOOXCSEyZWemBdZh4pFQhuEEpVxBiIWrCDv314G/lSfpI x2YeA1X8zRyyRgPPEDs4f6+9kHJX3oNmESZW1rMbsAI2mUVd2O2irAmDDvcyJ1kQYK10 zT+I5ULEqX1GQAISjbKQJ7Ec8ETM0aMSe14ZSY23hjwUALgXx4pYE1UBDGlJa9oX7H/E EkcgS8bdCCKuhOmcKanE+Elc4Hogn0Q8DdaisCtH4XJeskm2hgCGbL1v/CeRPi66Lbku PNFg== X-Gm-Message-State: AOAM530A4Fe6rY598h23eeOHKsBifjA9Gu52PW4hBNYNNjdthtN7ZrL6 mMe44Bm39LjHVk0xcY6++w== X-Google-Smtp-Source: ABdhPJztgREWPYXpbY24y3xYJ2ab/diXDmx2tovh1N/94fVvWPtBBHR0/+nE3r/ezlx7C21gRN1SYQ== X-Received: by 2002:ad4:5748:: with SMTP id q8mr23598337qvx.1.1595885925464; Mon, 27 Jul 2020 14:38:45 -0700 (PDT) Received: from localhost.localdomain ([209.94.141.207]) by smtp.gmail.com with ESMTPSA id y7sm17423217qta.36.2020.07.27.14.38.44 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 27 Jul 2020 14:38:44 -0700 (PDT) From: Peilin Ye To: Oleg Nesterov Cc: Peilin Ye , Dan Carpenter , Arnd Bergmann , Greg Kroah-Hartman , linux-kernel-mentees@lists.linuxfoundation.org, linux-kernel@vger.kernel.org Subject: [Linux-kernel-mentees] [PATCH] ptrace: Prevent kernel-infoleak in ptrace_get_syscall_info() Date: Mon, 27 Jul 2020 17:36:44 -0400 Message-Id: <20200727213644.328662-1-yepeilin.cs@gmail.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org ptrace_get_syscall_info() is copying uninitialized stack memory to userspace due to the compiler not initializing holes in statically allocated structures. Fix it by initializing `info` with memset(). Cc: stable@vger.kernel.org Fixes: 201766a20e30 ("ptrace: add PTRACE_GET_SYSCALL_INFO request") Suggested-by: Dan Carpenter Signed-off-by: Peilin Ye --- kernel/ptrace.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/kernel/ptrace.c b/kernel/ptrace.c index 43d6179508d6..e48d05b765b5 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -960,15 +960,17 @@ ptrace_get_syscall_info(struct task_struct *child, unsigned long user_size, void __user *datavp) { struct pt_regs *regs = task_pt_regs(child); - struct ptrace_syscall_info info = { - .op = PTRACE_SYSCALL_INFO_NONE, - .arch = syscall_get_arch(child), - .instruction_pointer = instruction_pointer(regs), - .stack_pointer = user_stack_pointer(regs), - }; + struct ptrace_syscall_info info; unsigned long actual_size = offsetof(struct ptrace_syscall_info, entry); unsigned long write_size; + memset(&info, 0, sizeof(info)); + + info.op = PTRACE_SYSCALL_INFO_NONE; + info.arch = syscall_get_arch(child); + info.instruction_pointer = instruction_pointer(regs); + info.stack_pointer = user_stack_pointer(regs); + /* * This does not need lock_task_sighand() to access * child->last_siginfo because ptrace_freeze_traced() -- 2.25.1