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 69248C4363A for ; Thu, 29 Oct 2020 15:57:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EF32F204FD for ; Thu, 29 Oct 2020 15:57:32 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="SDwP3bmC" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728489AbgJ2P5b (ORCPT ); Thu, 29 Oct 2020 11:57:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50644 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727966AbgJ2P5b (ORCPT ); Thu, 29 Oct 2020 11:57:31 -0400 Received: from mail-pg1-x543.google.com (mail-pg1-x543.google.com [IPv6:2607:f8b0:4864:20::543]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 128A2C0613CF for ; Thu, 29 Oct 2020 08:57:31 -0700 (PDT) Received: by mail-pg1-x543.google.com with SMTP id z24so2703944pgk.3 for ; Thu, 29 Oct 2020 08:57:31 -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=lTUHb90aDzUDND2rdKN/gp3QHYuHZ8nhx0Wf1vd5LKk=; b=SDwP3bmCckPi50TqdnAe0CylVXD+7kN3COsGzSsGefI8VFYkD7B3Ho/P8O8ynYZhCk LPG0V8C30rS+4DVC+7fLC0YlLyXQeKQuZgXXEPSM7P02ULNgtffyE6T4FN72Os+znoCT WnQpUcGYwect55FclV7ILmJNzmvf0ozzWSwgo0Vim71OZ4NNqwAihzOPHxEP4+BKkFaH Kpm5Wy8i6n3sxgFHOe1WXFNWOEcwB42oCsdq90WkqvGSu6NoXs4WTb6kRMnKaKXNmjOM 2V4yweaQFPXWzJ1B1p8JJ6ktFfCfDk1cGq6c3SYzXkgxfgKipSvnwZjBOkwXIrTvHByT L5oA== 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=lTUHb90aDzUDND2rdKN/gp3QHYuHZ8nhx0Wf1vd5LKk=; b=KfioNyzQ43mwyPsjZHsW9BY4rt08m6rGosfSZL4Y1svWcL012RCRMI2ND3qwuVkoMm P2r7BHJDUkvnZrBVYSrfIU2Mb1zIEgR5nyyYwTTUBbuUNR4DfzzlWj6l9XpFJmkza5An 9IwxAWsoFcV8W9mUGKVJ4JXIhqTiFcYe9qsIzGV4kwbnwv/0xsgXTUPp0bpwUyosWS1a uZJ7MOix6UPA5AKsvB8WTRyBbn6dscLKfrS/nkcy4Cc6+Q0TjXH8/MrHpGXqlzRiCDe6 cPOGeQItwKj0dWTu7wKb9ZuAsRU2+np6bCfQ978jvRaClUPnBTmYLmYJE6Qm5gznVWXo jqyA== X-Gm-Message-State: AOAM530K9xODalt2A6oHio067Ug91ICxvzvc5ApQvmyFy3QP3T9rNRbW 6v6SO0K7y76sCrUDrrOdW+Cl1Engva8= X-Google-Smtp-Source: ABdhPJxAu1s9liEFd0hMoyqKpHvMlfa8tbf7TMNPDGJQI94lKcxpaJvjw5F+/MHuBTIu8YmXYd9L0Q== X-Received: by 2002:a62:a10a:0:b029:154:fd62:ba90 with SMTP id b10-20020a62a10a0000b0290154fd62ba90mr4946523pff.62.1603987050708; Thu, 29 Oct 2020 08:57:30 -0700 (PDT) Received: from localhost (42-3-19-186.static.netvigator.com. [42.3.19.186]) by smtp.gmail.com with ESMTPSA id s11sm263481pjm.4.2020.10.29.08.57.29 (version=TLS1_2 cipher=ECDHE-ECDSA-CHACHA20-POLY1305 bits=256/256); Thu, 29 Oct 2020 08:57:30 -0700 (PDT) From: Qiujun Huang To: rostedt@goodmis.org, mingo@redhat.com, linux-kernel@vger.kernel.org Cc: Qiujun Huang Subject: [PATCH v3] tracing: Fix out of bounds write in get_trace_buf Date: Thu, 29 Oct 2020 23:57:14 +0800 Message-Id: <20201029155714.3935-1-hqjagain@gmail.com> X-Mailer: git-send-email 2.17.1 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The subscript should be nesting - 1, as nesting had self-added. Fixes: e2ace001176dc ("tracing: Choose static tp_printk buffer by explicit nesting count") Signed-off-by: Qiujun Huang --- v3: Modify the way of array reference instead. 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..daa96215e294 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -3132,7 +3132,7 @@ static char *get_trace_buf(void) /* Interrupts must see nesting incremented before we use the buffer */ barrier(); - return &buffer->buffer[buffer->nesting][0]; + return &buffer->buffer[buffer->nesting - 1][0]; } static void put_trace_buf(void) -- 2.17.1