From patchwork Sat Oct 24 00:22:50 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luiz Augusto von Dentz X-Patchwork-Id: 11854663 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,URIBL_BLOCKED,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 6C734C5517A for ; Sat, 24 Oct 2020 00:22:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2D78D22460 for ; Sat, 24 Oct 2020 00:22:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="GBq7fLKO" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756242AbgJXAWz (ORCPT ); Fri, 23 Oct 2020 20:22:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37450 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756220AbgJXAWz (ORCPT ); Fri, 23 Oct 2020 20:22:55 -0400 Received: from mail-pl1-x641.google.com (mail-pl1-x641.google.com [IPv6:2607:f8b0:4864:20::641]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 31C49C0613CE for ; Fri, 23 Oct 2020 17:22:54 -0700 (PDT) Received: by mail-pl1-x641.google.com with SMTP id o9so1881804plx.10 for ; Fri, 23 Oct 2020 17:22:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:subject:date:message-id:mime-version :content-transfer-encoding; bh=6KZCYxjRbYw95khCwcdrjK4U98Qheis9asdJR+uxgLc=; b=GBq7fLKOGhx1OuO8XOQ3N2ENyZx6LOB9P5vl35vpIWED1kbRIYHGILk6gD8kliWgJt arn3MW/XgR5vmhEwC7FVl3BfP9gwwHY4RG6zZm4o1jFM9Q7x3RkYEKWLGUwx102OmBfD AjD+I0L4hQnL7hqP0uN1IfPAxaUVe24wOF204C8xQ9ATj1HkioSV/Dn+WD4ZXTfy36HE VBJ1RJHNQjtxUzotdu2Y2PRBOqRgb+y8mXYuInQFU/iFqTJqdUzK91/5lUZv0epTZsM5 hdN7WFiugRVfe9MKWwEQJRKaDrCMDz7tH/WHSviw3zcZ74ScP/6SbpAYsdYxKAa2M4Hl vuIw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:subject:date:message-id:mime-version :content-transfer-encoding; bh=6KZCYxjRbYw95khCwcdrjK4U98Qheis9asdJR+uxgLc=; b=JWkc3n2W+J5+OCtWo15Iro+jsiZkAWabvb/EecPokF9JlmuxDSB0HXciuQADV2vjfT A3q0oJiowgmQoIaAcylwW7MlFlsOzTh1azBNbRD+llkFNgegKGD0kI8PZhMvfnGH1/bD H7EjUeEYl5LJ9wIWerRl2dnwqGKrqiYwaXM7PosaS7uiArBwQ8LNLkIpZCXRvZd5jm7N 7uFyP6tJ8rzsTkJHTmpQsjGRUx3zokcAPzuQiThtFgDaLd10BaZ5egzpWsRfEO+7uixM Rf7wcxoCv+wHmXd3G1PnXfwR0kvBzyaBIys9GO0fXHVSTEXbQSOs2RjpsG+FUoBBskqZ VmFA== X-Gm-Message-State: AOAM533ixumjmRkjiGkvc14mARmeMT091hKspCBw8vtYyXpInex5cRuV ApFFbIqPV+l4zRFxzja2Mwh44NE/epATHA== X-Google-Smtp-Source: ABdhPJxQa6jVjjQ2eZgg3r3iid1ZWSv2E3u9B2lsehgYSUgVBH3GYhcpYLpvBr4rIN5eKf+mH30o7w== X-Received: by 2002:a17:90a:2bc9:: with SMTP id n9mr5594291pje.219.1603498973440; Fri, 23 Oct 2020 17:22:53 -0700 (PDT) Received: from localhost.localdomain (c-71-56-157-77.hsd1.or.comcast.net. [71.56.157.77]) by smtp.gmail.com with ESMTPSA id q8sm3195099pfl.100.2020.10.23.17.22.52 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 23 Oct 2020 17:22:52 -0700 (PDT) From: Luiz Augusto von Dentz To: linux-bluetooth@vger.kernel.org Subject: [PATCH v3 1/2] Bluetooth: Fix not checking advertisement bondaries Date: Fri, 23 Oct 2020 17:22:50 -0700 Message-Id: <20201024002251.1389267-1-luiz.dentz@gmail.com> X-Mailer: git-send-email 2.26.2 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-bluetooth@vger.kernel.org From: Luiz Augusto von Dentz When receiving advertisements check if the length is actually within the skb, this also make use of skb_pull to advance on the skb->data instead of a custom ptr that way skb->len shall always indicates how much data is remaining and can be used to perform checks if there is enough data to parse. Fixes: a2ec905d1e160a33b2e210e45ad30445ef26ce0e ("Bluetooth: fix kernel oops in store_pending_adv_report") Signed-off-by: Luiz Augusto von Dentz --- net/bluetooth/hci_event.c | 73 ++++++++++++++++++++++++++++++--------- 1 file changed, 56 insertions(+), 17 deletions(-) diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c index a4c3703f2e94..6925c090a9e0 100644 --- a/net/bluetooth/hci_event.c +++ b/net/bluetooth/hci_event.c @@ -5599,24 +5599,41 @@ static void process_adv_report(struct hci_dev *hdev, u8 type, bdaddr_t *bdaddr, static void hci_le_adv_report_evt(struct hci_dev *hdev, struct sk_buff *skb) { u8 num_reports = skb->data[0]; - void *ptr = &skb->data[1]; hci_dev_lock(hdev); + skb_pull(skb, sizeof(num_reports)); + while (num_reports--) { - struct hci_ev_le_advertising_info *ev = ptr; + struct hci_ev_le_advertising_info *ev; s8 rssi; - if (ev->length <= HCI_MAX_AD_LENGTH) { - rssi = ev->data[ev->length]; - process_adv_report(hdev, ev->evt_type, &ev->bdaddr, - ev->bdaddr_type, NULL, 0, rssi, - ev->data, ev->length, false); - } else { - bt_dev_err(hdev, "Dropping invalid advertising data"); + if (skb->len < sizeof(*ev)) { + bt_dev_err(hdev, "Malformed advertising report"); + break; + } + + ev = (void *) skb->data; + skb_pull(skb, sizeof(*ev)); + + if (skb->len < ev->length || ev->length > HCI_MAX_AD_LENGTH) { + bt_dev_err(hdev, "Malformed advertising data"); + break; } - ptr += sizeof(*ev) + ev->length + 1; + skb_pull(skb, ev->length); + + if (skb->len < sizeof(rssi)) { + bt_dev_err(hdev, "Malformed advertising rssi"); + break; + } + + rssi = skb->data[0]; + skb_pull(skb, sizeof(rssi)); + + process_adv_report(hdev, ev->evt_type, &ev->bdaddr, + ev->bdaddr_type, NULL, 0, rssi, + ev->data, ev->length, false); } hci_dev_unlock(hdev); @@ -5669,15 +5686,31 @@ static u8 ext_evt_type_to_legacy(struct hci_dev *hdev, u16 evt_type) static void hci_le_ext_adv_report_evt(struct hci_dev *hdev, struct sk_buff *skb) { u8 num_reports = skb->data[0]; - void *ptr = &skb->data[1]; hci_dev_lock(hdev); + skb_pull(skb, sizeof(num_reports)); + while (num_reports--) { - struct hci_ev_le_ext_adv_report *ev = ptr; + struct hci_ev_le_ext_adv_report *ev; u8 legacy_evt_type; u16 evt_type; + if (skb->len < sizeof(*ev)) { + bt_dev_err(hdev, "Malformed ext advertising report"); + break; + } + + ev = (void *) skb->data; + skb_pull(skb, sizeof(*ev)); + + if (skb->len < ev->length || ev->length > HCI_MAX_AD_LENGTH) { + bt_dev_err(hdev, "Malformed ext advertising data"); + break; + } + + skb_pull(skb, ev->length); + evt_type = __le16_to_cpu(ev->evt_type); legacy_evt_type = ext_evt_type_to_legacy(hdev, evt_type); if (legacy_evt_type != LE_ADV_INVALID) { @@ -5687,7 +5720,6 @@ static void hci_le_ext_adv_report_evt(struct hci_dev *hdev, struct sk_buff *skb) !(evt_type & LE_EXT_ADV_LEGACY_PDU)); } - ptr += sizeof(*ev) + ev->length; } hci_dev_unlock(hdev); @@ -5873,19 +5905,26 @@ static void hci_le_direct_adv_report_evt(struct hci_dev *hdev, struct sk_buff *skb) { u8 num_reports = skb->data[0]; - void *ptr = &skb->data[1]; hci_dev_lock(hdev); + skb_pull(skb, sizeof(num_reports)); + while (num_reports--) { - struct hci_ev_le_direct_adv_info *ev = ptr; + struct hci_ev_le_direct_adv_info *ev; + + if (skb->len < sizeof(*ev)) { + bt_dev_err(hdev, "Malformed direct advertising"); + break; + } + + ev = (void *) skb->data; + skb_pull(skb, sizeof(*ev)); process_adv_report(hdev, ev->evt_type, &ev->bdaddr, ev->bdaddr_type, &ev->direct_addr, ev->direct_addr_type, ev->rssi, NULL, 0, false); - - ptr += sizeof(*ev); } hci_dev_unlock(hdev);