From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AB8JxZqqOVV5yyvhaWRoPpE9u0APWMSp/fz2qhrpS7rdBibz93j1hJkTQe9xeS7mkI/SxVDGndz4 ARC-Seal: i=1; a=rsa-sha256; t=1526631472; cv=none; d=google.com; s=arc-20160816; b=KxtSABldvxfO82kYORqfJAEdAbpsKUAbIiWhEMQmgutUS0y1+ukX9KUQ9rQBbDcvHk pZ69jhQ2JK7EE3n727HhjwTVTJxszM5NXvxI6PWaRvNUBfy17L/NLwu3WfcOsksV0A7+ LQFXB077b1G6ULdA4CK9zYY9PuH6a1u0T3uoVIhltjJD1u+97mY/681qd6faTlLkAF3H RHkqaF2oSYH1PhazrDIHEJ2jXmRiL1HdrDOFvf6SjWjwc5tirReiJlKl9DmboSXo+yg6 gEdCKcWYx24+A4zF1sMlDX50NbvBYST0RbgYA4aJ7dPmGU16cGQ03rDSn4NFmuO9+oXr h7dw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:user-agent:references:in-reply-to:message-id:date :subject:cc:to:from:dkim-signature:arc-authentication-results; bh=+1aN0g0XzyOrPSYVrRQxGm1J4D6PaMzcI5NPIouOCBk=; b=iPtjSHjmL8fhckkFQK9axaXUZTBQMMKscPDzIqmw41+ceuYxz6Y9tm1WOLdq6/xx04 57pnKFoa/yKhkK1fviBh1y1wdm0IfQNBulTRX7DY5irhC/r6vgMaOF8hVilrFpYmk2mS cXgwOpp9ISWTeVtAW/OVj+oUiB/yykX9YcklyXrBn/D6cLWVbPQ7ndQ9GQyTjwtjx+mt qzGWvu06ij8Ogk1rldeEdcUBNAyWS/Fzwe1dknrOnO5tAgVV2tqmZPikn0Ua5XzzYrTA U8TW4+VcmHXhouQ+7HDNPU2fuOrwHl3drzYdXQnytUATwwiO1V4pl5s646K6PI9eYdEV Z23A== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=YFBaC1Mk; spf=pass (google.com: domain of srs0=xuy6=if=linuxfoundation.org=gregkh@kernel.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=SRS0=XuY6=IF=linuxfoundation.org=gregkh@kernel.org Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=YFBaC1Mk; spf=pass (google.com: domain of srs0=xuy6=if=linuxfoundation.org=gregkh@kernel.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=SRS0=XuY6=IF=linuxfoundation.org=gregkh@kernel.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ursula Braun , syzbot+03faa2dc16b8b64be396@syzkaller.appspotmail.com, "David S. Miller" Subject: [PATCH 4.16 15/55] net/smc: restrict non-blocking connect finish Date: Fri, 18 May 2018 10:15:11 +0200 Message-Id: <20180518081458.215956909@linuxfoundation.org> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180518081457.428920292@linuxfoundation.org> References: <20180518081457.428920292@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-LABELS: =?utf-8?b?IlxcU2VudCI=?= X-GMAIL-THRID: =?utf-8?q?1600789123047137185?= X-GMAIL-MSGID: =?utf-8?q?1600789123047137185?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.16-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ursula Braun [ Upstream commit 784813aed6ba24a1f24e7e11d9d0f208cee37a7d ] The smc_poll code tries to finish connect() if the socket is in state SMC_INIT and polling of the internal CLC-socket returns with EPOLLOUT. This makes sense for a select/poll call following a connect call, but not without preceding connect(). With this patch smc_poll starts connect logic only, if the CLC-socket is no longer in its initial state TCP_CLOSE. In addition, a poll error on the internal CLC-socket is always propagated to the SMC socket. With this patch the code path mentioned by syzbot https://syzkaller.appspot.com/bug?extid=03faa2dc16b8b64be396 is no longer possible. Signed-off-by: Ursula Braun Reported-by: syzbot+03faa2dc16b8b64be396@syzkaller.appspotmail.com Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/smc/af_smc.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) --- a/net/smc/af_smc.c +++ b/net/smc/af_smc.c @@ -1165,13 +1165,15 @@ static __poll_t smc_poll(struct file *fi /* delegate to CLC child sock */ release_sock(sk); mask = smc->clcsock->ops->poll(file, smc->clcsock, wait); - /* if non-blocking connect finished ... */ lock_sock(sk); - if ((sk->sk_state == SMC_INIT) && (mask & EPOLLOUT)) { - sk->sk_err = smc->clcsock->sk->sk_err; - if (sk->sk_err) { - mask |= EPOLLERR; - } else { + sk->sk_err = smc->clcsock->sk->sk_err; + if (sk->sk_err) { + mask |= EPOLLERR; + } else { + /* if non-blocking connect finished ... */ + if (sk->sk_state == SMC_INIT && + mask & EPOLLOUT && + smc->clcsock->sk->sk_state != TCP_CLOSE) { rc = smc_connect_rdma(smc); if (rc < 0) mask |= EPOLLERR;