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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1A675C433F5 for ; Tue, 9 Nov 2021 01:26:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F0DB6610A8 for ; Tue, 9 Nov 2021 01:26:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241493AbhKIB3d (ORCPT ); Mon, 8 Nov 2021 20:29:33 -0500 Received: from mail.kernel.org ([198.145.29.99]:44356 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242267AbhKIBRL (ORCPT ); Mon, 8 Nov 2021 20:17:11 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 8BF4161ACE; Tue, 9 Nov 2021 01:06:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1636420012; bh=tAeMvQvi+vg3kKnhpw01b73sBeDIm/BIgffhPNvBl1w=; h=From:To:Cc:Subject:Date:From; b=AGpminiHhbD/FxdnRC4F3mb4HzgDcYEfoNjd9BvUIQSB1f+sG4ReH60LH49CZS+ut fVKSBsFRLBWp8Zc6wrHEBFaKqAnJIvIiFkA6qDZx0LsoY+yphXykjTwp5WAy8cBhEG 7KBgrdrJnigtys6liyZOU9FyKzMJQ5MgeamzUZZwsetkT7CwD+SUg4RUkK7o0wPptC 2XqeuJFEylzgHYJGAgP1hzagOaaP4uORXPRt2yni10wPV6cdFY0lDtAc7yIeNod2CY H8NRyfqh0UYkO8/x6fh3G0oMSpxaiN7OEqobMiF/anv6odtKO06sAv0PTMviU2XEmm xjUoHhfTL9mLg== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Takashi Iwai , Marcel Holtmann , Sasha Levin , johan.hedberg@gmail.com, luiz.dentz@gmail.com, davem@davemloft.net, kuba@kernel.org, linux-bluetooth@vger.kernel.org, netdev@vger.kernel.org Subject: [PATCH AUTOSEL 4.14 01/39] Bluetooth: sco: Fix lock_sock() blockage by memcpy_from_msg() Date: Mon, 8 Nov 2021 20:06:11 -0500 Message-Id: <20211109010649.1191041-1-sashal@kernel.org> X-Mailer: git-send-email 2.33.0 MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Takashi Iwai [ Upstream commit 99c23da0eed4fd20cae8243f2b51e10e66aa0951 ] The sco_send_frame() also takes lock_sock() during memcpy_from_msg() call that may be endlessly blocked by a task with userfaultd technique, and this will result in a hung task watchdog trigger. Just like the similar fix for hci_sock_sendmsg() in commit 92c685dc5de0 ("Bluetooth: reorganize functions..."), this patch moves the memcpy_from_msg() out of lock_sock() for addressing the hang. This should be the last piece for fixing CVE-2021-3640 after a few already queued fixes. Signed-off-by: Takashi Iwai Signed-off-by: Marcel Holtmann Signed-off-by: Sasha Levin --- net/bluetooth/sco.c | 24 ++++++++++++++++-------- 1 file changed, 16 insertions(+), 8 deletions(-) diff --git a/net/bluetooth/sco.c b/net/bluetooth/sco.c index f681e7ce89457..a5cc8942fc3f8 100644 --- a/net/bluetooth/sco.c +++ b/net/bluetooth/sco.c @@ -255,7 +255,8 @@ static int sco_connect(struct hci_dev *hdev, struct sock *sk) return err; } -static int sco_send_frame(struct sock *sk, struct msghdr *msg, int len) +static int sco_send_frame(struct sock *sk, void *buf, int len, + unsigned int msg_flags) { struct sco_conn *conn = sco_pi(sk)->conn; struct sk_buff *skb; @@ -267,15 +268,11 @@ static int sco_send_frame(struct sock *sk, struct msghdr *msg, int len) BT_DBG("sk %p len %d", sk, len); - skb = bt_skb_send_alloc(sk, len, msg->msg_flags & MSG_DONTWAIT, &err); + skb = bt_skb_send_alloc(sk, len, msg_flags & MSG_DONTWAIT, &err); if (!skb) return err; - if (memcpy_from_msg(skb_put(skb, len), msg, len)) { - kfree_skb(skb); - return -EFAULT; - } - + memcpy(skb_put(skb, len), buf, len); hci_send_sco(conn->hcon, skb); return len; @@ -692,6 +689,7 @@ static int sco_sock_sendmsg(struct socket *sock, struct msghdr *msg, size_t len) { struct sock *sk = sock->sk; + void *buf; int err; BT_DBG("sock %p, sk %p", sock, sk); @@ -703,14 +701,24 @@ static int sco_sock_sendmsg(struct socket *sock, struct msghdr *msg, if (msg->msg_flags & MSG_OOB) return -EOPNOTSUPP; + buf = kmalloc(len, GFP_KERNEL); + if (!buf) + return -ENOMEM; + + if (memcpy_from_msg(buf, msg, len)) { + kfree(buf); + return -EFAULT; + } + lock_sock(sk); if (sk->sk_state == BT_CONNECTED) - err = sco_send_frame(sk, msg, len); + err = sco_send_frame(sk, buf, len, msg->msg_flags); else err = -ENOTCONN; release_sock(sk); + kfree(buf); return err; } -- 2.33.0