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 X-Spam-Level: X-Spam-Status: No, score=-6.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 D6198C10F05 for ; Mon, 1 Apr 2019 17:04:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A62FF2192B for ; Mon, 1 Apr 2019 17:04:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1554138284; bh=WoEa3q0YyyWdBGBdju/xqBNIuedmy9P5EcUkZYqxyR0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=whTqROa9k1TBJDcE9xuc0ubuZRF91bUEdD083IsO1OhpsXGzDg5Chx+93yy4aZl0Z E2MGpecUs69IvEr7toHJM0ZQ+BcxwfE9Wq4O15Yn4fyk3pHZK7WWnzkKx72LVFIhdW GsmvU/yPhcbpByteo+qH48bFDj/24QYFbBUlYbcg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728589AbfDAREm (ORCPT ); Mon, 1 Apr 2019 13:04:42 -0400 Received: from mail.kernel.org ([198.145.29.99]:49290 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728007AbfDAREm (ORCPT ); Mon, 1 Apr 2019 13:04:42 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B032621924; Mon, 1 Apr 2019 17:04:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1554138281; bh=WoEa3q0YyyWdBGBdju/xqBNIuedmy9P5EcUkZYqxyR0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=st6gnmKtrTJN/CdGUV20aKE8YBxmlKGM9EDzGmRTvwd2tJwROvVGIscRH5ksyEH5I LNGKDny9aKhJvyAZY+VQfMtuLKt/ITnJh3iesb2KXJYvVnDNwLnx0VKipOMGtIXQqV 3ewXpw9SngO1L6/ptv62/FHoqeaWp1OlVO/RDEnY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+ec1b7575afef85a0e5ca@syzkaller.appspotmail.com, Xin Long , Neil Horman , "David S. Miller" Subject: [PATCH 5.0 021/146] sctp: use memdup_user instead of vmemdup_user Date: Mon, 1 Apr 2019 19:00:33 +0200 Message-Id: <20190401170050.375411846@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190401170048.449559024@linuxfoundation.org> References: <20190401170048.449559024@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 5.0-stable review patch. If anyone has any objections, please let me know. ------------------ From: Xin Long [ Upstream commit ef82bcfa671b9a635bab5fa669005663d8b177c5 ] In sctp_setsockopt_bindx()/__sctp_setsockopt_connectx(), it allocates memory with addrs_size which is passed from userspace. We used flag GFP_USER to put some more restrictions on it in Commit cacc06215271 ("sctp: use GFP_USER for user-controlled kmalloc"). However, since Commit c981f254cc82 ("sctp: use vmemdup_user() rather than badly open-coding memdup_user()"), vmemdup_user() has been used, which doesn't check GFP_USER flag when goes to vmalloc_*(). So when addrs_size is a huge value, it could exhaust memory and even trigger oom killer. This patch is to use memdup_user() instead, in which GFP_USER would work to limit the memory allocation with a huge addrs_size. Note we can't fix it by limiting 'addrs_size', as there's no demand for it from RFC. Reported-by: syzbot+ec1b7575afef85a0e5ca@syzkaller.appspotmail.com Fixes: c981f254cc82 ("sctp: use vmemdup_user() rather than badly open-coding memdup_user()") Signed-off-by: Xin Long Acked-by: Neil Horman Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/sctp/socket.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -999,7 +999,7 @@ static int sctp_setsockopt_bindx(struct if (unlikely(addrs_size <= 0)) return -EINVAL; - kaddrs = vmemdup_user(addrs, addrs_size); + kaddrs = memdup_user(addrs, addrs_size); if (unlikely(IS_ERR(kaddrs))) return PTR_ERR(kaddrs); @@ -1007,7 +1007,7 @@ static int sctp_setsockopt_bindx(struct addr_buf = kaddrs; while (walk_size < addrs_size) { if (walk_size + sizeof(sa_family_t) > addrs_size) { - kvfree(kaddrs); + kfree(kaddrs); return -EINVAL; } @@ -1018,7 +1018,7 @@ static int sctp_setsockopt_bindx(struct * causes the address buffer to overflow return EINVAL. */ if (!af || (walk_size + af->sockaddr_len) > addrs_size) { - kvfree(kaddrs); + kfree(kaddrs); return -EINVAL; } addrcnt++; @@ -1054,7 +1054,7 @@ static int sctp_setsockopt_bindx(struct } out: - kvfree(kaddrs); + kfree(kaddrs); return err; } @@ -1329,7 +1329,7 @@ static int __sctp_setsockopt_connectx(st if (unlikely(addrs_size <= 0)) return -EINVAL; - kaddrs = vmemdup_user(addrs, addrs_size); + kaddrs = memdup_user(addrs, addrs_size); if (unlikely(IS_ERR(kaddrs))) return PTR_ERR(kaddrs); @@ -1349,7 +1349,7 @@ static int __sctp_setsockopt_connectx(st err = __sctp_connect(sk, kaddrs, addrs_size, flags, assoc_id); out_free: - kvfree(kaddrs); + kfree(kaddrs); return err; }