From patchwork Tue Aug 17 10:31:08 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pavel Skripkin X-Patchwork-Id: 499652 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=-15.7 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, URIBL_BLOCKED, 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 B4A1BC4320A for ; Tue, 17 Aug 2021 10:31:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 99FED600CC for ; Tue, 17 Aug 2021 10:31:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239626AbhHQKbx (ORCPT ); Tue, 17 Aug 2021 06:31:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58250 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236220AbhHQKbu (ORCPT ); Tue, 17 Aug 2021 06:31:50 -0400 Received: from mail-lf1-x12d.google.com (mail-lf1-x12d.google.com [IPv6:2a00:1450:4864:20::12d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 272DCC06179A; Tue, 17 Aug 2021 03:31:17 -0700 (PDT) Received: by mail-lf1-x12d.google.com with SMTP id w20so40435722lfu.7; Tue, 17 Aug 2021 03:31:17 -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=qMZOt5ueMN6fg1XgUmhU0282KCRD6RMSAKl1MQqd8U8=; b=hd2QvJ0U+Lcn6l8mKOtXOKCcXnW4/nG6Be8smA6IJf/AmJMVuZG/A5jO9cQvnj70oV 6vCk0bmCKVFrEQ+x48N1CeUT1p64dz0uagrMWVZ1JkvaIAl8yxatXT1+Kvn5z89rABGF gRhElFWJXVAQh++1aG7z9I+WciHBJG+YVSP4Mx7FDT0Gf/v5msQKTomjW6bAtk9yztMo Pz/SrJdP0SbIXE2PpwlKL2xq6K0U1U+urS/vVXx8SV8I7yHbDkzowTl0nQKyWE6o7HKN cruoMMZyv8gNwp8B3FmB2Rk5nyWfQR2MOlfALaQBdoLn27bZiCgrlt/jUnkCp56p46mA BH1w== 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=qMZOt5ueMN6fg1XgUmhU0282KCRD6RMSAKl1MQqd8U8=; b=gCeYZ1Rkyy6Hif9wWgn7QGdgFdLqTuPK3RB3T9hiv6yfQHlIa5hf4RqPzieeHcMZR7 /Aif9UTEhdO2j8Nk3awm5nxsFYphwpzk0gdmR+qpc5Kl5rEYfumh4cI5x4cG8V8t03rq 3cQxO+vQfnOrptMmbo94CFnEWIEyD7fyrMic4vkyZfZulk7wlJGZzPxt0Pkcyd63c5ON frivk/owDXSdpcTHXzprj0qP7mogUJbot2IACyNJQ0QmFXdlLstz5yyU3jDHte/qNt4l rmSTvcZwdvtiR5kcoTP4rM7O+cTBKPzZPhvQBtEWw8mMXd1hz41V7UqMFIlnsfE7EqaB xCyQ== X-Gm-Message-State: AOAM532T0SswnLnTyRF9PL/zWGw6X5h/QXKDtT8V6WYsnwCEgGtOQ4rN PreYJOCLx+shzy+RiHa+AD4i18ZKQoVdS2/c X-Google-Smtp-Source: ABdhPJwoWbG83NrILDBrdTVFNpU3zS+CDvxpw6b1IS8FPovIvgEu/VXweXWMoo4FeLjjCu59rALz+Q== X-Received: by 2002:a05:6512:3889:: with SMTP id n9mr1861128lft.589.1629196275367; Tue, 17 Aug 2021 03:31:15 -0700 (PDT) Received: from localhost.localdomain ([46.235.67.232]) by smtp.gmail.com with ESMTPSA id h8sm136335ljh.27.2021.08.17.03.31.14 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 17 Aug 2021 03:31:14 -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] Bluetooth: add timeout sanity check to hci_inquiry Date: Tue, 17 Aug 2021 13:31:08 +0300 Message-Id: <20210817103108.1160-1-paskripkin@gmail.com> X-Mailer: git-send-email 2.32.0 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@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 and add constant to hsi_sock.h to inform userspace, that hci_inquiry_req::length field has maximum possible value. 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 --- Hi, Bluetooth maintainers/reviewers! I believe, 60 seconds will be more than enough for inquiry request. I've searched for examples on the internet and maximum ir.length I found was 8. Maybe, we have users, which need more than 60 seconds... I look forward to receiving your views on this value. --- include/net/bluetooth/hci_sock.h | 1 + net/bluetooth/hci_core.c | 5 +++++ 2 files changed, 6 insertions(+) diff --git a/include/net/bluetooth/hci_sock.h b/include/net/bluetooth/hci_sock.h index 9949870f7d78..1cd63d4da00b 100644 --- a/include/net/bluetooth/hci_sock.h +++ b/include/net/bluetooth/hci_sock.h @@ -168,6 +168,7 @@ struct hci_inquiry_req { __u16 dev_id; __u16 flags; __u8 lap[3]; +#define HCI_INQUIRY_MAX_TIMEOUT 30 __u8 length; __u8 num_rsp; }; diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c index e1a545c8a69f..104babf67351 100644 --- a/net/bluetooth/hci_core.c +++ b/net/bluetooth/hci_core.c @@ -1343,6 +1343,11 @@ int hci_inquiry(void __user *arg) goto done; } + if (ir.length > HCI_INQUIRY_MAX_TIMEOUT) { + 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) {