From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-659992-1519838073-2-16886735291643904048 X-Sieve: CMU Sieve 3.0 X-Spam-known-sender: no X-Spam-score: 0.0 X-Spam-hits: BAYES_00 -1.9, HEADER_FROM_DIFFERENT_DOMAINS 0.249, ME_NOAUTH 0.01, RCVD_IN_DNSWL_HI -5, T_RP_MATCHES_RCVD -0.01, LANGUAGES en, BAYES_USED global, SA_VERSION 3.4.0 X-Spam-source: IP='209.132.180.67', Host='vger.kernel.org', Country='CN', FromHeader='uk', MailFrom='org' X-Spam-charsets: plain='UTF-8' X-Resolved-to: greg@kroah.com X-Delivered-to: greg@kroah.com X-Mail-from: stable-owner@vger.kernel.org ARC-Seal: i=1; a=rsa-sha256; cv=none; d=messagingengine.com; s=arctest; t=1519838072; b=PweKC1qm9PZn3KQ+9RO3K4dlrFSZKjT6hMpeDcSgsLKBX88 TwA9hJdjTnVvs5ZqFM7M8kqgmKXNYxBjWtcxg5l6H3mSFpDkPmgaziafDN1t5mcY Oyd+ROz52M6gMCzKzLmzccDUnngDBaDqynxASKmgY1dmM3AJXLbDQnkw7oncWUtJ gomnLQwEqSeFWj9FCBqHQGM1zRx2M6bWVFqdVzZae7wS8L9I+Ni3+mpsxrhxQf2W ZooFBbofeIGWd2tQjgTAVVWEpyEJ9wWnAflxelco72wloj/p13sg0wYDc/7EZEgO 8w8nqhbDbkYyvowNzv8sdw8w1TXdOlR5ZZKmsjw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=content-type:content-transfer-encoding :mime-version:from:to:cc:date:message-id:subject:in-reply-to :sender:list-id; s=arctest; t=1519838072; bh=aRfJWo9rNcPi4TZDF3S ikHP05OiaZgfnWN8DXOvNb7Q=; b=G3RJPFbafAVB1/LhL5itamMxfNPQL+2vrE/ xWaHitpCc8J3fDekHnIQwSXWtfD/4cJGHvbO2dME6+/2ZoS2f7CISlECIXyjheG3 SDRgzgslZodslRwtyl2ijm2NpKnI3Te2scyWwTw1WcrA9X2KRe53g8gYMY9ucCMZ VNINdP/nCmzg9F+5sxcm49eszK4hzCaHyEkrhiBalibPRpLdTXp+kR3vwaMeJaap eFatrctqQgjHXMyzCFaNftZozS3yT++lO12CPqkjwJCDwWjWvCrzH/FUHwNSd56d Sb6RtSgBF5i5FMEhVxKhLHmzTJZichNCskfxvh/kZi+JwXyW81w== ARC-Authentication-Results: i=1; mx5.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=decadent.org.uk; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=decadent.org.uk header.result=pass header_is_org_domain=yes Authentication-Results: mx5.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=decadent.org.uk; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=decadent.org.uk header.result=pass header_is_org_domain=yes Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932592AbeB1ROQ (ORCPT ); Wed, 28 Feb 2018 12:14:16 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:34272 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932916AbeB1Psl (ORCPT ); Wed, 28 Feb 2018 10:48:41 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, syzbot+7b7b518b1228d2743963@syzkaller.appspotmail.com, "Marcelo Ricardo Leitner" , "David S. Miller" , "Neil Horman" , "Xin Long" Date: Wed, 28 Feb 2018 15:20:18 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 211/254] sctp: do not allow the v4 socket to bind a v4mapped v6 address In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8011:400e:2:6f00:88c8:c921:d332 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: stable-owner@vger.kernel.org X-Mailing-List: stable@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 3.16.55-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Xin Long commit c5006b8aa74599ce19104b31d322d2ea9ff887cc upstream. The check in sctp_sockaddr_af is not robust enough to forbid binding a v4mapped v6 addr on a v4 socket. The worse thing is that v4 socket's bind_verify would not convert this v4mapped v6 addr to a v4 addr. syzbot even reported a crash as the v4 socket bound a v6 addr. This patch is to fix it by doing the common sa.sa_family check first, then AF_INET check for v4mapped v6 addrs. Fixes: 7dab83de50c7 ("sctp: Support ipv6only AF_INET6 sockets.") Reported-by: syzbot+7b7b518b1228d2743963@syzkaller.appspotmail.com Acked-by: Neil Horman Signed-off-by: Xin Long Acked-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings --- net/sctp/socket.c | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-) --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -303,16 +303,14 @@ static struct sctp_af *sctp_sockaddr_af( if (len < sizeof (struct sockaddr)) return NULL; + if (!opt->pf->af_supported(addr->sa.sa_family, opt)) + return NULL; + /* V4 mapped address are really of AF_INET family */ if (addr->sa.sa_family == AF_INET6 && - ipv6_addr_v4mapped(&addr->v6.sin6_addr)) { - if (!opt->pf->af_supported(AF_INET, opt)) - return NULL; - } else { - /* Does this PF support this AF? */ - if (!opt->pf->af_supported(addr->sa.sa_family, opt)) - return NULL; - } + ipv6_addr_v4mapped(&addr->v6.sin6_addr) && + !opt->pf->af_supported(AF_INET, opt)) + return NULL; /* If we get this far, af is valid. */ af = sctp_get_af_specific(addr->sa.sa_family);