Subject: [PATCH 20/54] net: sched: initialize with 0 before setting erspan md->u

From: Xin Long <[email-masked]>
Date: Sun, 13 Sep 2020 19:43:03 +0800

[ Upstream commit 8e1b3ac4786680c2d2b5a24e38a2d714c3bcd1ef ]

In fl_set_erspan_opt(), all bits of erspan md was set 1, as this
function is also used to set opt MASK. However, when setting for
md->u.index for opt VALUE, the rest bits of the union md->u will
be left 1. It would cause to fail the match of the whole md when
version is 1 and only index is set.

This patch is to fix by initializing with 0 before setting erspan
md->u.

Reported-by: Shuang Li <[email-masked]>
Fixes: 79b1011cb33d ("net: sched: allow flower to match erspan options")
Signed-off-by: Xin Long <[email-masked]>
Signed-off-by: David S. Miller <[email-masked]>
---
 net/sched/cls_flower.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/sched/cls_flower.c b/net/sched/cls_flower.c
index e30bd969fc48..5fe145d97f52 100644
--- a/net/sched/cls_flower.c
+++ b/net/sched/cls_flower.c
@@ -1215,6 +1215,7 @@ static int fl_set_erspan_opt(const struct nlattr *nla, struct fl_flow_key *key,
 		}
 		if (tb[TCA_FLOWER_KEY_ENC_OPT_ERSPAN_INDEX]) {
 			nla = tb[TCA_FLOWER_KEY_ENC_OPT_ERSPAN_INDEX];
+			memset(&md->u, 0x00, sizeof(md->u));
 			md->u.index = nla_get_be32(nla);
 		}
 	} else if (md->version == 2) {
-- 
2.26.2