netdev - [PATCH iproute2-next] bridge: fdb: Use 'struct ndmsg' for FDB dumping

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-next>] [day] [month] [year] [list]

Date:   Sun, 30 Dec 2018 17:14:54 +0000
From:   Ido Schimmel <idosch@...lanox.com>
To:     "netdev@...r.kernel.org" <netdev@...r.kernel.org>
CC:     "dsahern@...il.com" <dsahern@...il.com>,
        "stephen@...workplumber.org" <stephen@...workplumber.org>,
        Ido Schimmel <idosch@...lanox.com>
Subject: [PATCH iproute2-next] bridge: fdb: Use 'struct ndmsg' for FDB dumping

Since commit aea41afcfd6d ("ip bridge: Set NETLINK_GET_STRICT_CHK on
socket") iproute2 uses strict checking on kernels that support it. This
causes FDB dumping to fail [1], as iproute2 uses 'struct ifinfomsg'
whereas the kernel expects 'struct ndmsg'.

Note that with this change iproute2 continues to work on old kernels
that do not support strict checking, but contain the fix introduced in
kernel commit bd961c9bc664 ("rtnetlink: fix rtnl_fdb_dump() for ndmsg
header").

[1]
# bridge fdb show
[ 5365.137224] netlink: 4 bytes leftover after parsing attributes in process `bridge'.
Error: bytes leftover after parsing attributes.
Dump terminated

Fixes: aea41afcfd6d ("ip bridge: Set NETLINK_GET_STRICT_CHK on socket")
Signed-off-by: Ido Schimmel <idosch@...lanox.com>
---
 bridge/fdb.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/bridge/fdb.c b/bridge/fdb.c
index a5abc1b6c78d..a7a0d8052307 100644
--- a/bridge/fdb.c
+++ b/bridge/fdb.c
@@ -260,16 +260,16 @@ static int fdb_show(int argc, char **argv)
 {
 	struct {
 		struct nlmsghdr	n;
-		struct ifinfomsg	ifm;
+		struct ndmsg		ndm;
 		char			buf[256];
 	} req = {
-		.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg)),
-		.ifm.ifi_family = PF_BRIDGE,
+		.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ndmsg)),
+		.ndm.ndm_family = PF_BRIDGE,
 	};
 
 	char *filter_dev = NULL;
 	char *br = NULL;
-	int msg_size = sizeof(struct ifinfomsg);
+	int msg_size = sizeof(struct ndmsg);
 
 	while (argc > 0) {
 		if ((strcmp(*argv, "brport") == 0) || strcmp(*argv, "dev") == 0) {
@@ -313,10 +313,10 @@ static int fdb_show(int argc, char **argv)
 		filter_index = ll_name_to_index(filter_dev);
 		if (!filter_index)
 			return nodev(filter_dev);
-		req.ifm.ifi_index = filter_index;
+		req.ndm.ndm_ifindex = filter_index;
 	}
 
-	if (rtnl_dump_request(&rth, RTM_GETNEIGH, &req.ifm, msg_size) < 0) {
+	if (rtnl_dump_request(&rth, RTM_GETNEIGH, &req.ndm, msg_size) < 0) {
 		perror("Cannot send dump request");
 		exit(1);
 	}
-- 
2.20.1