From patchwork Tue Sep 29 17:32:31 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anmol Karn X-Patchwork-Id: 11806409 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 23057618 for ; Tue, 29 Sep 2020 17:32:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EE9BE2076B for ; Tue, 29 Sep 2020 17:32:53 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="L3b+sbb1" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728459AbgI2Rct (ORCPT ); Tue, 29 Sep 2020 13:32:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37058 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725554AbgI2Rct (ORCPT ); Tue, 29 Sep 2020 13:32:49 -0400 Received: from mail-pf1-x442.google.com (mail-pf1-x442.google.com [IPv6:2607:f8b0:4864:20::442]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 89380C061755; Tue, 29 Sep 2020 10:32:49 -0700 (PDT) Received: by mail-pf1-x442.google.com with SMTP id z19so5241330pfn.8; Tue, 29 Sep 2020 10:32:49 -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=xf7UYd55bBypBMw3nNJvaFu6tO4OkMryDnkxOfP4mCQ=; b=L3b+sbb1ZAJZvbidh3Qs2l8xQ/zyz/rGbhWqi3+dHNjqGS9VFkuw2TcY05NlVObSlS C7D93tqsTEzDPJzm0/8tb55prGjb/hfPt9tkKWScgCxv8xgPsJheyuFlzoy3MwPjh9++ Uw2KIcbqIN4Gz1PPBd7Z2WvnQz7WPp7PVXx6/iRnA6OpUP7T4vpqhUzdGnnl9HCM9RoE 8jWIA1WJilZ34mDpIlpYNTxjEiRUpC/atZuqfVDWjfjMzvVlGjZHFr/opJa9iqJYAXQ0 4uFaYeiu89+ESDndbe10lndLfbPEiuLssadC518emRGFzU1gOf0YmI/UC7maKLgLremH nLWw== 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=xf7UYd55bBypBMw3nNJvaFu6tO4OkMryDnkxOfP4mCQ=; b=aq51k6AxnIDoqwt/8PUMxJhc/tqeKpl2PkMWGIPCLO4HMzH0NUwcrsgkFy+uYz+umu 0sDKJmabhD6v3vY3GOO+FDWgs4vSQtjzgGo3F7l0kuDnPZREIPwZxe3Ztj7hkPFZeaTL 0M06UKrIkxpSl73mkV7ts6nsmvN3X0JaUQIJZF2s+GOFi0Mx9Zgh55aOt07fxbffgHF0 QZfgvbqH7C3QVGLwrjo+ZdieOF79R8PBduFyp5OmXzq7Vn1214tYHRoauysvJAxoykg2 aXgV15M+xNBqaI/roxiWJi30uhdmJCaapCrHL9WcQ6OTdByOIbEU+x7aSy8YmU3jWaku Tb2w== X-Gm-Message-State: AOAM532X/8duci0fT4vxs10ZxHnOOs76JFJo4tSibDt8i+BDWKc5F+qF Q40onfDLu9wdGZhipw14oHc= X-Google-Smtp-Source: ABdhPJwc0s8N7Xf0hxKKvWjT3DfKxAZtK9X2pcW+qM/TaWv5j/tdAoTup1/sAlPie73LycYp7I8z/g== X-Received: by 2002:a62:93:0:b029:13e:d13d:a085 with SMTP id 141-20020a6200930000b029013ed13da085mr4916522pfa.28.1601400768890; Tue, 29 Sep 2020 10:32:48 -0700 (PDT) Received: from localhost.localdomain ([45.118.167.204]) by smtp.googlemail.com with ESMTPSA id d17sm6270070pfq.157.2020.09.29.10.32.43 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 29 Sep 2020 10:32:47 -0700 (PDT) From: Anmol Karn To: marcel@holtmann.org, johan.hedberg@gmail.com Cc: linux-kernel-mentees@lists.linuxfoundation.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com, netdev@vger.kernel.org, linux-bluetooth@vger.kernel.org, kuba@kernel.org, davem@davemloft.net, anmol.karan123@gmail.com, syzbot+0bef568258653cff272f@syzkaller.appspotmail.com Subject: [Linux-kernel-mentees] [PATCH] net: bluetooth: Fix null pointer dereference in hci_event_packet() Date: Tue, 29 Sep 2020 23:02:31 +0530 Message-Id: <20200929173231.396261-1-anmol.karan123@gmail.com> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200914154405.GC18329@kadam> References: <20200914154405.GC18329@kadam> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-bluetooth@vger.kernel.org AMP_MGR is getting derefernced in hci_phy_link_complete_evt(), when called from hci_event_packet() and there is a possibility, that hcon->amp_mgr may not be found when accessing after initialization of hcon. - net/bluetooth/hci_event.c:4945 The bug seems to get triggered in this line: bredr_hcon = hcon->amp_mgr->l2cap_conn->hcon; Fix it by adding a NULL check for the hcon->amp_mgr before checking the ev-status. Fixes: d5e911928bd8 ("Bluetooth: AMP: Process Physical Link Complete evt") Reported-and-tested-by: syzbot+0bef568258653cff272f@syzkaller.appspotmail.com Link: https://syzkaller.appspot.com/bug?extid=0bef568258653cff272f Signed-off-by: Anmol Karn --- Cahnge in v2: - Replaced IS_ERR_OR_NULL check with NULL check only (Suggested by: Dan Carpenter ) - Added "Fixes:" tag (Suggested by: Dan Carpenter ) net/bluetooth/hci_event.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c index 4b7fc430793c..b084142c578e 100644 --- a/net/bluetooth/hci_event.c +++ b/net/bluetooth/hci_event.c @@ -4936,6 +4936,11 @@ static void hci_phy_link_complete_evt(struct hci_dev *hdev, return; } + if (!hcon->amp_mgr) { + hci_dev_unlock(hdev); + return 0; + } + if (ev->status) { hci_conn_del(hcon); hci_dev_unlock(hdev);