[PATCH v2] llc2: Remove the condition operator in llc_stat_ev_rx_null_dsap_xid_c and llc_stat_ev_rx_null_dsap_test_c.

From: Chan Shu Tak, Alex
Date: Mon Dec 16 2019 - 23:11:47 EST


From: "Chan Shu Tak, Alex" <alexchan@xxxxxxxxxxx>

When a frame with NULL DSAP is received, llc_station_rcv is called.
In turn, llc_stat_ev_rx_null_dsap_xid_c is called to check if it is a NULL
XID frame. The original condition operator returns 1 when the incoming
frame is not a NULL XID frame and 0 otherwise. As a result, an incoming
NULL TEST frame would trigger an XID response instead.

To fix the error, we just need to remove the condition operator.

The same error is found in llc_stat_ev_rx_null_dsap_test_c and fixed.

Signed-off-by: Chan Shu Tak, Alex <alexchan@xxxxxxxxxxx>
---
net/llc/llc_station.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/llc/llc_station.c b/net/llc/llc_station.c
index 90955d7..c29170e 100644
--- a/net/llc/llc_station.c
+++ b/net/llc/llc_station.c
@@ -32,7 +32,7 @@ static int llc_stat_ev_rx_null_dsap_xid_c(struct sk_buff *skb)
return LLC_PDU_IS_CMD(pdu) && /* command PDU */
LLC_PDU_TYPE_IS_U(pdu) && /* U type PDU */
LLC_U_PDU_CMD(pdu) == LLC_1_PDU_CMD_XID &&
- !pdu->dsap ? 1 : 0; /* NULL DSAP value */
+ !pdu->dsap; /* NULL DSAP value */
}

static int llc_stat_ev_rx_null_dsap_test_c(struct sk_buff *skb)
@@ -42,7 +42,7 @@ static int llc_stat_ev_rx_null_dsap_test_c(struct sk_buff *skb)
return LLC_PDU_IS_CMD(pdu) && /* command PDU */
LLC_PDU_TYPE_IS_U(pdu) && /* U type PDU */
LLC_U_PDU_CMD(pdu) == LLC_1_PDU_CMD_TEST &&
- !pdu->dsap ? 1 : 0; /* NULL DSAP */
+ !pdu->dsap; /* NULL DSAP */
}

static int llc_station_ac_send_xid_r(struct sk_buff *skb)
--
1.8.3.1