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=-12.6 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=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 AE074C55179 for ; Thu, 29 Oct 2020 15:33:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3EB8620731 for ; Thu, 29 Oct 2020 15:33:18 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="K3SW5pIn" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728200AbgJ2PdQ (ORCPT ); Thu, 29 Oct 2020 11:33:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46698 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728222AbgJ2Pb7 (ORCPT ); Thu, 29 Oct 2020 11:31:59 -0400 Received: from mail-pg1-x544.google.com (mail-pg1-x544.google.com [IPv6:2607:f8b0:4864:20::544]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EA5A5C0613CF for ; Thu, 29 Oct 2020 08:31:58 -0700 (PDT) Received: by mail-pg1-x544.google.com with SMTP id x13so2623709pgp.7 for ; Thu, 29 Oct 2020 08:31:58 -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; bh=POKnlFfl2V9OZ8B9RgrGBFa9+xh/s0EHhEzNswRMK4M=; b=K3SW5pIn8+AD+g1YUYPABSi42jUMlyuzFTRT/i8n+Ek/EUQB7SJ2J4FvGqydWiksCh fcXA7XFB7oTReWhWTSuk//Kosg0zlPQhNlhwpTWWd72mvhBkRUFNYHmAJOpHpJ7ooz+E FY8S0ArE1emZGYXGciswq4B2nQFs7Wy+hlBgdwbtCX76UK7oQLm2XTfMn/20eRqZIqbW Zk/jCWo4zrrENF2BN4CRy4UxCU6tBfN6HHANo+8+1gapPfFS4ZB9mH2CgKF60wNPnDDJ sOzSOXd6J905skl73ffKv5/lk7X7ngcg4hxGsiXRiRMwc65LYthTFAKSFNZc0tzLOOPT qdrQ== 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; bh=POKnlFfl2V9OZ8B9RgrGBFa9+xh/s0EHhEzNswRMK4M=; b=PpfraunMrN+Cq1JCDQFh1S2ouexIj1FWXwj3QdBxF24o1l887OnwpKwEMgSesO2aAU 8wdkZCitlCa8P4rckKtCbKGVhuOStwKAil6DhEAcr7IqORNs8GB6LHhu7sJg+w9Exaeg 1g2r9n/UO+P09IchDi/JyHjPK8KHqyhB1mF+VDGSvYcCC2tjYRTBDhr13oOr2WeOrxlA WBB8ssXnBdGiV99aJSIim1BPE4XyAQv4Fq4la1/dFvVU/8qMKayDtO0fcDfq+0krvqcn G9KJFJiphxjRum6T/fqYoiOpc6ZloiV2Pj/DhzUQqwyXyQUsGSVyTZY+W8VxUzZdPZ+q vJPg== X-Gm-Message-State: AOAM532OWGWNYeEzPv+YyiEbgUSEsHnpkDPkZ+cS0nWcGGS2tmExU+fB suZ1BHsncLsg+kBmovQYz94= X-Google-Smtp-Source: ABdhPJyYhoO9QxGQkc2+glDzbmnxc1qp3YlVE1fEs0lilptHSHDQYk6yq9xzZObfxXuO9xYED2Wx4Q== X-Received: by 2002:a63:e542:: with SMTP id z2mr4606132pgj.320.1603985518584; Thu, 29 Oct 2020 08:31:58 -0700 (PDT) Received: from localhost (42-3-19-186.static.netvigator.com. [42.3.19.186]) by smtp.gmail.com with ESMTPSA id a22sm3382229pfk.29.2020.10.29.08.31.57 (version=TLS1_2 cipher=ECDHE-ECDSA-CHACHA20-POLY1305 bits=256/256); Thu, 29 Oct 2020 08:31:58 -0700 (PDT) From: Qiujun Huang To: rostedt@goodmis.org, mingo@redhat.com, linux-kernel@vger.kernel.org Cc: Qiujun Huang Subject: [PATCH v2] tracing: Fix out of bounds write in get_trace_buf Date: Thu, 29 Oct 2020 23:31:40 +0800 Message-Id: <20201029153140.3643-1-hqjagain@gmail.com> X-Mailer: git-send-email 2.17.1 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The boundary condition should be 3 as we access buffer[buffer->nesting][0]. Fixes: e2ace001176dc ("tracing: Choose static tp_printk buffer by explicit nesting count") Signed-off-by: Qiujun Huang --- v2: Fix a typo in the title. --- kernel/trace/trace.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 528971714fc6..196a4b7de48a 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -3125,7 +3125,7 @@ static char *get_trace_buf(void) { struct trace_buffer_struct *buffer = this_cpu_ptr(trace_percpu_buffer); - if (!buffer || buffer->nesting >= 4) + if (!buffer || buffer->nesting >= 3) return NULL; buffer->nesting++; -- 2.17.1