From patchwork Thu Aug 19 15:15:21 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pavel Skripkin X-Patchwork-Id: 12447405 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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,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 A7BE3C4338F for ; Thu, 19 Aug 2021 15:15:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8760A60E76 for ; Thu, 19 Aug 2021 15:15:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238663AbhHSPQI (ORCPT ); Thu, 19 Aug 2021 11:16:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54316 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232821AbhHSPQG (ORCPT ); Thu, 19 Aug 2021 11:16:06 -0400 Received: from mail-lj1-x236.google.com (mail-lj1-x236.google.com [IPv6:2a00:1450:4864:20::236]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E5F1BC061575; Thu, 19 Aug 2021 08:15:28 -0700 (PDT) Received: by mail-lj1-x236.google.com with SMTP id c12so12150528ljr.5; Thu, 19 Aug 2021 08:15:28 -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:in-reply-to:references :mime-version:content-transfer-encoding; bh=vZjXPmOCbplWUcGOomjfHqgKyvdCopt0JA72wssuj18=; b=qIY/kbWXI66jpRCw0g3aG654Q0g3cTSO8/Gc+/KbOiUuKcq1KvHgOn0PebKOA038o5 3k8lPgXmhG9O/nHDJMsFkEo7XRKFt4AS8jEJDyTmVQ7ELbZoGJlwuDrgoagiox71Ko/y cI2h/DicOTZJRlGA9nPeYMp3M5mWeF9mjQ3hsPr7MRFr3dWK1YPGjVsDwdqwN9ejjy8n 2Ncq3D/mnYsf8TenPmorYaUJj2cW/0MuAtja7TCJKOLBEU/+SXolsAZz/g7dEIeeQyyq pb/0rA4MfdCDK1jY7pnjTyx9HEhr2WMH8cVTzMSSJYvotOF6lcykoBHAszN6WOxWtfC5 XxvA== 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:in-reply-to :references:mime-version:content-transfer-encoding; bh=vZjXPmOCbplWUcGOomjfHqgKyvdCopt0JA72wssuj18=; b=Vrd5B5q/dUS2nsJC41hlp4VeyEwuO0jrqlu9u8JYwOZ6Xe2LLP1+MK36URm9f9YIeG cxeLwWbkafsqQMlWOZEOKwyP7MXOYP7D2AQNJ+ORdqoJOgK4j9/vfpKj2bqNkJA74yDs lYi89WRA7Q4CzkrHacBFgJj6hxWGC3jZtkEFWOJrb0AcM/g3c4bNlogay6F39GgqdWn4 mVMD8YdoBEObY8mYyiKuOho8Zmc8sB0izRUc4QPvbwHrd18YmRHynUjx560zwu73XO/0 6SSO55Cl6rh3vByS8fF7zEQkVAuQxktdp5TJdnGznuvN3jjBxNgDhvDPAdaX1pz7T5vB bI0g== X-Gm-Message-State: AOAM530isGLb7MN630ZU3y7ROwP3IVfGZ1pB17muaRfGEwnn5LYoMxya 8oksDwOHm8RbKBavCzGe4Jo= X-Google-Smtp-Source: ABdhPJyAvTUD4BUAIU3FuCccZygogstrXmZzgehkWq/i4HWe50f4H9ujcTO+s3wFDonDLj7w6WFo+A== X-Received: by 2002:a2e:a54c:: with SMTP id e12mr12894890ljn.139.1629386127253; Thu, 19 Aug 2021 08:15:27 -0700 (PDT) Received: from localhost.localdomain ([46.235.66.127]) by smtp.gmail.com with ESMTPSA id br33sm334616lfb.46.2021.08.19.08.15.26 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 19 Aug 2021 08:15:26 -0700 (PDT) From: Pavel Skripkin To: marcel@holtmann.org, johan.hedberg@gmail.com, luiz.dentz@gmail.com, davem@davemloft.net Cc: linux-bluetooth@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Pavel Skripkin , syzbot+be2baed593ea56c6a84c@syzkaller.appspotmail.com Subject: [PATCH v2] Bluetooth: add timeout sanity check to hci_inquiry Date: Thu, 19 Aug 2021 18:15:21 +0300 Message-Id: <20210819151521.17380-1-paskripkin@gmail.com> X-Mailer: git-send-email 2.32.0 In-Reply-To: <0038C6D9-DEAF-4CB2-874C-00F6CEFCF26C@holtmann.org> References: <0038C6D9-DEAF-4CB2-874C-00F6CEFCF26C@holtmann.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-bluetooth@vger.kernel.org Syzbot hit "task hung" bug in hci_req_sync(). The problem was in unreasonable huge inquiry timeout passed from userspace. Fix it by adding sanity check for timeout value to hci_inquiry(). Since hci_inquiry() is the only user of hci_req_sync() with user controlled timeout value, it makes sense to check timeout value in hci_inquiry() and don't touch hci_req_sync(). Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-and-tested-by: syzbot+be2baed593ea56c6a84c@syzkaller.appspotmail.com Signed-off-by: Pavel Skripkin --- Changes in v2: Removed define + added comment suggested by Marcel --- net/bluetooth/hci_core.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c index e1a545c8a69f..170f513efa86 100644 --- a/net/bluetooth/hci_core.c +++ b/net/bluetooth/hci_core.c @@ -1343,6 +1343,12 @@ int hci_inquiry(void __user *arg) goto done; } + /* Restrict maximum inquiry length to 60 seconds */ + if (ir.length > 60) { + err = -EINVAL; + goto done; + } + hci_dev_lock(hdev); if (inquiry_cache_age(hdev) > INQUIRY_CACHE_AGE_MAX || inquiry_cache_empty(hdev) || ir.flags & IREQ_CACHE_FLUSH) {