From patchwork Mon Jun 3 14:21:12 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Neil Horman X-Patchwork-Id: 1109284 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=tuxdriver.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 45Hcgk0QYhz9s1c for ; Tue, 4 Jun 2019 00:21:54 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728987AbfFCOVx (ORCPT ); Mon, 3 Jun 2019 10:21:53 -0400 Received: from charlotte.tuxdriver.com ([70.61.120.58]:33956 "EHLO smtp.tuxdriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727429AbfFCOVx (ORCPT ); Mon, 3 Jun 2019 10:21:53 -0400 Received: from cpe-2606-a000-111b-405a-0-0-0-162e.dyn6.twc.com ([2606:a000:111b:405a::162e] helo=localhost) by smtp.tuxdriver.com with esmtpsa (TLSv1:AES256-SHA:256) (Exim 4.63) (envelope-from ) id 1hXnqL-0000Tk-6t; Mon, 03 Jun 2019 10:21:50 -0400 From: Neil Horman To: linux-sctp@vger.kernel.org Cc: Neil Horman , syzbot+f7e9153b037eac9b1df8@syzkaller.appspotmail.com, Marcelo Ricardo Leitner , "David S. Miller" , netdev@vger.kernel.org Subject: [PATCH] Fix memory leak in sctp_process_init Date: Mon, 3 Jun 2019 10:21:12 -0400 Message-Id: <20190603142112.20229-1-nhorman@tuxdriver.com> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 X-Spam-Score: -2.9 (--) X-Spam-Status: No Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org syzbot found the following leak in sctp_process_init BUG: memory leak unreferenced object 0xffff88810ef68400 (size 1024): comm "syz-executor273", pid 7046, jiffies 4294945598 (age 28.770s) hex dump (first 32 bytes): 1d de 28 8d de 0b 1b e3 b5 c2 f9 68 fd 1a 97 25 ..(........h...% 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<00000000a02cebbd>] kmemleak_alloc_recursive include/linux/kmemleak.h:55 [inline] [<00000000a02cebbd>] slab_post_alloc_hook mm/slab.h:439 [inline] [<00000000a02cebbd>] slab_alloc mm/slab.c:3326 [inline] [<00000000a02cebbd>] __do_kmalloc mm/slab.c:3658 [inline] [<00000000a02cebbd>] __kmalloc_track_caller+0x15d/0x2c0 mm/slab.c:3675 [<000000009e6245e6>] kmemdup+0x27/0x60 mm/util.c:119 [<00000000dfdc5d2d>] kmemdup include/linux/string.h:432 [inline] [<00000000dfdc5d2d>] sctp_process_init+0xa7e/0xc20 net/sctp/sm_make_chunk.c:2437 [<00000000b58b62f8>] sctp_cmd_process_init net/sctp/sm_sideeffect.c:682 [inline] [<00000000b58b62f8>] sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1384 [inline] [<00000000b58b62f8>] sctp_side_effects net/sctp/sm_sideeffect.c:1194 [inline] [<00000000b58b62f8>] sctp_do_sm+0xbdc/0x1d60 net/sctp/sm_sideeffect.c:1165 [<0000000044e11f96>] sctp_assoc_bh_rcv+0x13c/0x200 net/sctp/associola.c:1074 [<00000000ec43804d>] sctp_inq_push+0x7f/0xb0 net/sctp/inqueue.c:95 [<00000000726aa954>] sctp_backlog_rcv+0x5e/0x2a0 net/sctp/input.c:354 [<00000000d9e249a8>] sk_backlog_rcv include/net/sock.h:950 [inline] [<00000000d9e249a8>] __release_sock+0xab/0x110 net/core/sock.c:2418 [<00000000acae44fa>] release_sock+0x37/0xd0 net/core/sock.c:2934 [<00000000963cc9ae>] sctp_sendmsg+0x2c0/0x990 net/sctp/socket.c:2122 [<00000000a7fc7565>] inet_sendmsg+0x64/0x120 net/ipv4/af_inet.c:802 [<00000000b732cbd3>] sock_sendmsg_nosec net/socket.c:652 [inline] [<00000000b732cbd3>] sock_sendmsg+0x54/0x70 net/socket.c:671 [<00000000274c57ab>] ___sys_sendmsg+0x393/0x3c0 net/socket.c:2292 [<000000008252aedb>] __sys_sendmsg+0x80/0xf0 net/socket.c:2330 [<00000000f7bf23d1>] __do_sys_sendmsg net/socket.c:2339 [inline] [<00000000f7bf23d1>] __se_sys_sendmsg net/socket.c:2337 [inline] [<00000000f7bf23d1>] __x64_sys_sendmsg+0x23/0x30 net/socket.c:2337 [<00000000a8b4131f>] do_syscall_64+0x76/0x1a0 arch/x86/entry/common.c:3 The problem was that the peer.cookie value points to an skb allocated area on the first pass through this function, at which point it is overwritten with a heap allocated value, but in certain cases, where a COOKIE_ECHO chunk is included in the packet, a second pass through sctp_process_init is made, where the cookie value is re-allocated, leaking the first allocation. Fix is to always allocate the cookie value, and free it when we are done using it. Signed-off-by: Neil Horman Reported-by: syzbot+f7e9153b037eac9b1df8@syzkaller.appspotmail.com CC: Marcelo Ricardo Leitner CC: "David S. Miller" CC: netdev@vger.kernel.org --- net/sctp/associola.c | 1 + net/sctp/sm_make_chunk.c | 12 +++--------- net/sctp/sm_sideeffect.c | 5 +++++ 3 files changed, 9 insertions(+), 9 deletions(-) diff --git a/net/sctp/associola.c b/net/sctp/associola.c index d2c7d0d2abc1..718b9917844e 100644 --- a/net/sctp/associola.c +++ b/net/sctp/associola.c @@ -393,6 +393,7 @@ void sctp_association_free(struct sctp_association *asoc) kfree(asoc->peer.peer_random); kfree(asoc->peer.peer_chunks); kfree(asoc->peer.peer_hmacs); + kfree(asoc->peer.cookie); /* Release the transport structures. */ list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c index 72e74503f9fc..ff365f22a3c1 100644 --- a/net/sctp/sm_make_chunk.c +++ b/net/sctp/sm_make_chunk.c @@ -2431,14 +2431,6 @@ int sctp_process_init(struct sctp_association *asoc, struct sctp_chunk *chunk, /* Peer Rwnd : Current calculated value of the peer's rwnd. */ asoc->peer.rwnd = asoc->peer.i.a_rwnd; - /* Copy cookie in case we need to resend COOKIE-ECHO. */ - cookie = asoc->peer.cookie; - if (cookie) { - asoc->peer.cookie = kmemdup(cookie, asoc->peer.cookie_len, gfp); - if (!asoc->peer.cookie) - goto clean_up; - } - /* RFC 2960 7.2.1 The initial value of ssthresh MAY be arbitrarily * high (for example, implementations MAY use the size of the receiver * advertised window). @@ -2607,7 +2599,9 @@ static int sctp_process_param(struct sctp_association *asoc, case SCTP_PARAM_STATE_COOKIE: asoc->peer.cookie_len = ntohs(param.p->length) - sizeof(struct sctp_paramhdr); - asoc->peer.cookie = param.cookie->body; + asoc->peer.cookie = kmemdup(param.cookie->body, asoc->peer.cookie_len, gfp); + if (!asoc->peer.cookie) + retval = 0; break; case SCTP_PARAM_HEARTBEAT_INFO: diff --git a/net/sctp/sm_sideeffect.c b/net/sctp/sm_sideeffect.c index 4aa03588f87b..27ddf2d8f001 100644 --- a/net/sctp/sm_sideeffect.c +++ b/net/sctp/sm_sideeffect.c @@ -898,6 +898,11 @@ static void sctp_cmd_new_state(struct sctp_cmd_seq *cmds, asoc->rto_initial; } + if (sctp_state(asoc, ESTABLISHED)) { + kfree(asoc->peer.cookie); + asoc->peer.cookie = NULL; + } + if (sctp_state(asoc, ESTABLISHED) || sctp_state(asoc, CLOSED) || sctp_state(asoc, SHUTDOWN_RECEIVED)) {