netdev - [PATCH v2] j1939: transport: make sure EOMA is send with the total message size set

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:   Fri, 25 Oct 2019 15:04:13 +0200
From:   Oleksij Rempel <o.rempel@...gutronix.de>
To:     dev.kurt@...dijck-laurijssen.be, mkl@...gutronix.de,
        wg@...ndegger.com
Cc:     Oleksij Rempel <o.rempel@...gutronix.de>, kernel@...gutronix.de,
        linux-can@...r.kernel.org, netdev@...r.kernel.org
Subject: [PATCH v2] j1939: transport: make sure EOMA is send with the total message size set

We was sending malformed EOMA with total message size set to 0. So, fix this
bug and add sanity check to the RX path.

Signed-off-by: Oleksij Rempel <o.rempel@...gutronix.de>
---
 net/can/j1939/transport.c | 20 +++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/net/can/j1939/transport.c b/net/can/j1939/transport.c
index fe000ea757ea..e5f1a56994c6 100644
--- a/net/can/j1939/transport.c
+++ b/net/can/j1939/transport.c
@@ -1273,9 +1273,27 @@ j1939_xtp_rx_abort(struct j1939_priv *priv, struct sk_buff *skb,
 static void
 j1939_xtp_rx_eoma_one(struct j1939_session *session, struct sk_buff *skb)
 {
+	struct j1939_sk_buff_cb *skcb = j1939_skb_to_cb(skb);
+	const u8 *dat;
+	int len;
+
 	if (j1939_xtp_rx_cmd_bad_pgn(session, skb))
 		return;
 
+	dat = skb->data;
+
+	if (skcb->addr.type == J1939_ETP)
+		len = j1939_etp_ctl_to_size(dat);
+	else
+		len = j1939_tp_ctl_to_size(dat);
+
+	if (session->total_message_size != len) {
+		netdev_warn_once(session->priv->ndev,
+				 "%s: 0x%p: Incorrect size. Expected: %i; got: %i.\n",
+				 __func__, session, session->total_message_size,
+				 len);
+	}
+
 	netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session);
 
 	session->pkt.tx_acked = session->pkt.total;
@@ -1432,7 +1450,7 @@ j1939_session *j1939_session_fresh_new(struct j1939_priv *priv,
 	skcb = j1939_skb_to_cb(skb);
 	memcpy(skcb, rel_skcb, sizeof(*skcb));
 
-	session = j1939_session_new(priv, skb, skb->len);
+	session = j1939_session_new(priv, skb, size);
 	if (!session) {
 		kfree_skb(skb);
 		return NULL;
-- 
2.23.0