netdev - [PATCH net-next 12/15] tipc: Prevent loss of fragmented messages over unicast links

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1328575968-20643-13-git-send-email-paul.gortmaker@windriver.com>
Date:	Mon,  6 Feb 2012 19:52:45 -0500
From:	Paul Gortmaker <paul.gortmaker@...driver.com>
To:	davem@...emloft.net
Cc:	netdev@...r.kernel.org, allan.stephens@...driver.com,
	ying.xue@...driver.com
Subject: [PATCH net-next 12/15] tipc: Prevent loss of fragmented messages over unicast links

From: Allan Stephens <allan.stephens@...driver.com>

Modifies unicast link endpoint logic so an incoming fragmented message
is not lost if reassembly cannot begin because there is no buffer big
enough to hold the entire reassembled message. The link endpoint now
ignores the first fragment completely, which causes the sending node to
retransmit the first fragment so that reassembly can be re-attempted.

Previously, the sender would have had no reason to retransmit the 1st
fragment, so we would never have a chance to re-try the allocation.

Signed-off-by: Allan Stephens <allan.stephens@...driver.com>
---
 net/tipc/link.c |   13 ++++++++++---
 1 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/net/tipc/link.c b/net/tipc/link.c
index cce9537..d8b0a22 100644
--- a/net/tipc/link.c
+++ b/net/tipc/link.c
@@ -1774,6 +1774,7 @@ protocol_check:
 					head = link_insert_deferred_queue(l_ptr,
 									  head);
 				if (likely(msg_is_dest(msg, tipc_own_addr))) {
+					int ret;
 deliver:
 					if (likely(msg_isdata(msg))) {
 						tipc_node_unlock(n_ptr);
@@ -1798,11 +1799,15 @@ deliver:
 						continue;
 					case MSG_FRAGMENTER:
 						l_ptr->stats.recv_fragments++;
-						if (tipc_link_recv_fragment(&l_ptr->defragm_buf,
-									    &buf, &msg)) {
+						ret = tipc_link_recv_fragment(
+							&l_ptr->defragm_buf,
+							&buf, &msg);
+						if (ret == 1) {
 							l_ptr->stats.recv_fragmented++;
 							goto deliver;
 						}
+						if (ret == -1)
+							l_ptr->next_in_no--;
 						break;
 					case CHANGEOVER_PROTOCOL:
 						type = msg_type(msg);
@@ -2632,7 +2637,9 @@ int tipc_link_recv_fragment(struct sk_buff **pending, struct sk_buff **fb,
 			set_fragm_size(pbuf, fragm_sz);
 			set_expected_frags(pbuf, exp_fragm_cnt - 1);
 		} else {
-			warn("Link unable to reassemble fragmented message\n");
+			dbg("Link unable to reassemble fragmented message\n");
+			buf_discard(fbuf);
+			return -1;
 		}
 		buf_discard(fbuf);
 		return 0;
-- 
1.7.9

--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html