net: sched: fix erspan_opt settings in cls_flower

When matching erspan_opt in cls_flower, only the (version, dir, hwid)
fields are relevant. However, in fl_set_erspan_opt() it initializes
all bits of erspan_opt and its mask to 1. This inadvertently requires
packets to match not only the (version, dir, hwid) fields but also the
other fields that are unexpectedly set to 1.

This patch resolves the issue by ensuring that only the (version, dir,
hwid) fields are configured in fl_set_erspan_opt(), leaving the other
fields to 0 in erspan_opt.

Fixes: 79b1011cb33d ("net: sched: allow flower to match erspan options")
Reported-by: Shuang Li <shuali@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Reviewed-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/sched/cls_flower.c b/net/sched/cls_flower.c
index e280c27cb9f9af455fa049bab237942f2266d026..1008ec8a464c9333a3d978083aa40f91733cb89e 100644 (file)
--- a/net/sched/cls_flower.c
+++ b/net/sched/cls_flower.c
@@ -1369,7 +1369,6 @@ static int fl_set_erspan_opt(const struct nlattr *nla, struct fl_flow_key *key,
        int err;
 
        md = (struct erspan_metadata *)&key->enc_opts.data[key->enc_opts.len];
-       memset(md, 0xff, sizeof(*md));
        md->version = 1;
 
        if (!depth)
@@ -1398,9 +1397,9 @@ static int fl_set_erspan_opt(const struct nlattr *nla, struct fl_flow_key *key,
                        NL_SET_ERR_MSG(extack, "Missing tunnel key erspan option index");
                        return -EINVAL;
                }
+               memset(&md->u.index, 0xff, sizeof(md->u.index));
                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) {
@@ -1409,10 +1408,12 @@ static int fl_set_erspan_opt(const struct nlattr *nla, struct fl_flow_key *key,
                        NL_SET_ERR_MSG(extack, "Missing tunnel key erspan option dir or hwid");
                        return -EINVAL;
                }
+               md->u.md2.dir = 1;
                if (tb[TCA_FLOWER_KEY_ENC_OPT_ERSPAN_DIR]) {
                        nla = tb[TCA_FLOWER_KEY_ENC_OPT_ERSPAN_DIR];
                        md->u.md2.dir = nla_get_u8(nla);
                }
+               set_hwid(&md->u.md2, 0xff);
                if (tb[TCA_FLOWER_KEY_ENC_OPT_ERSPAN_HWID]) {
                        nla = tb[TCA_FLOWER_KEY_ENC_OPT_ERSPAN_HWID];
                        set_hwid(&md->u.md2, nla_get_u8(nla));