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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2F214C433FE for ; Mon, 24 Jan 2022 19:08:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344775AbiAXTIC (ORCPT ); Mon, 24 Jan 2022 14:08:02 -0500 Received: from ams.source.kernel.org ([145.40.68.75]:32904 "EHLO ams.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344554AbiAXTFh (ORCPT ); Mon, 24 Jan 2022 14:05:37 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id B4C68B8122F; Mon, 24 Jan 2022 19:05:35 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E992EC340E5; Mon, 24 Jan 2022 19:05:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1643051134; bh=nmjZSEe7ziaN378FuR/msL8ZIqf1i8BMls2oqwT16d4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=w/6Gk6okjnVlB2acgNyIlzl3WEPmxPSq450s65c+qescYquB02aM6lOMMKOtq342a vRnEA87kmdD/KVqXzo8uCMpQF8ENE/nE3Y5WVA3OznhLSe1ybO8xHkIhWcEIcDwblp 8BScHwRVfXOG2y28BuKUiZd/dRqrRvPBGXxcKx7I= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Pavel Skripkin , Marcel Holtmann , Sasha Levin , syzbot+e3fcb9c4f3c2a931dc40@syzkaller.appspotmail.com Subject: [PATCH 4.14 038/186] Bluetooth: stop proccessing malicious adv data Date: Mon, 24 Jan 2022 19:41:53 +0100 Message-Id: <20220124183938.352879074@linuxfoundation.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220124183937.101330125@linuxfoundation.org> References: <20220124183937.101330125@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Pavel Skripkin [ Upstream commit 3a56ef719f0b9682afb8a86d64b2399e36faa4e6 ] Syzbot reported slab-out-of-bounds read in hci_le_adv_report_evt(). The problem was in missing validaion check. We should check if data is not malicious and we can read next data block. If we won't check ptr validness, code can read a way beyond skb->end and it can cause problems, of course. Fixes: e95beb414168 ("Bluetooth: hci_le_adv_report_evt code refactoring") Reported-and-tested-by: syzbot+e3fcb9c4f3c2a931dc40@syzkaller.appspotmail.com Signed-off-by: Pavel Skripkin Signed-off-by: Marcel Holtmann Signed-off-by: Sasha Levin --- net/bluetooth/hci_event.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c index 5186f199d892c..eca596a56f46b 100644 --- a/net/bluetooth/hci_event.c +++ b/net/bluetooth/hci_event.c @@ -4967,7 +4967,8 @@ static void hci_le_adv_report_evt(struct hci_dev *hdev, struct sk_buff *skb) struct hci_ev_le_advertising_info *ev = ptr; s8 rssi; - if (ev->length <= HCI_MAX_AD_LENGTH) { + if (ev->length <= HCI_MAX_AD_LENGTH && + ev->data + ev->length <= skb_tail_pointer(skb)) { rssi = ev->data[ev->length]; process_adv_report(hdev, ev->evt_type, &ev->bdaddr, ev->bdaddr_type, NULL, 0, rssi, @@ -4977,6 +4978,11 @@ static void hci_le_adv_report_evt(struct hci_dev *hdev, struct sk_buff *skb) } ptr += sizeof(*ev) + ev->length + 1; + + if (ptr > (void *) skb_tail_pointer(skb) - sizeof(*ev)) { + bt_dev_err(hdev, "Malicious advertising data. Stopping processing"); + break; + } } hci_dev_unlock(hdev); -- 2.34.1