net: sched: cls_bpf: Undo tcf_bind_filter in case of an error

If cls_bpf_offload errors out, we must also undo tcf_bind_filter that
was done before the error.

Fix that by calling tcf_unbind_filter in errout_parms.

Fixes: eadb4148 ("net: cls_bpf: add support for marking filters as hardware-only")
Signed-off-by: Victor Nogueira <victor@mojatatu.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Reviewed-by: Pedro Tammela <pctammela@mojatatu.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/sched/cls_bpf.c

@@ -406,56 +406,6 @@ static int cls_bpf_prog_from_efd(struct nlattr **tb, struct cls_bpf_prog *prog,
 	return 0;
 }
 
-static int cls_bpf_set_parms(struct net *net, struct tcf_proto *tp,
-			     struct cls_bpf_prog *prog, unsigned long base,
-			     struct nlattr **tb, struct nlattr *est, u32 flags,
-			     struct netlink_ext_ack *extack)
-{
-	bool is_bpf, is_ebpf, have_exts = false;
-	u32 gen_flags = 0;
-	int ret;
-
-	is_bpf = tb[TCA_BPF_OPS_LEN] && tb[TCA_BPF_OPS];
-	is_ebpf = tb[TCA_BPF_FD];
-	if ((!is_bpf && !is_ebpf) || (is_bpf && is_ebpf))
-		return -EINVAL;
-
-	ret = tcf_exts_validate(net, tp, tb, est, &prog->exts, flags,
-				extack);
-	if (ret < 0)
-		return ret;
-
-	if (tb[TCA_BPF_FLAGS]) {
-		u32 bpf_flags = nla_get_u32(tb[TCA_BPF_FLAGS]);
-
-		if (bpf_flags & ~TCA_BPF_FLAG_ACT_DIRECT)
-			return -EINVAL;
-
-		have_exts = bpf_flags & TCA_BPF_FLAG_ACT_DIRECT;
-	}
-	if (tb[TCA_BPF_FLAGS_GEN]) {
-		gen_flags = nla_get_u32(tb[TCA_BPF_FLAGS_GEN]);
-		if (gen_flags & ~CLS_BPF_SUPPORTED_GEN_FLAGS ||
-		    !tc_flags_valid(gen_flags))
-			return -EINVAL;
-	}
-
-	prog->exts_integrated = have_exts;
-	prog->gen_flags = gen_flags;
-
-	ret = is_bpf ? cls_bpf_prog_from_ops(tb, prog) :
-		       cls_bpf_prog_from_efd(tb, prog, gen_flags, tp);
-	if (ret < 0)
-		return ret;
-
-	if (tb[TCA_BPF_CLASSID]) {
-		prog->res.classid = nla_get_u32(tb[TCA_BPF_CLASSID]);
-		tcf_bind_filter(tp, &prog->res, base);
-	}
-
-	return 0;
-}
-
 static int cls_bpf_change(struct net *net, struct sk_buff *in_skb,
 			  struct tcf_proto *tp, unsigned long base,
 			  u32 handle, struct nlattr **tca,
@@ -463,9 +413,12 @@ static int cls_bpf_change(struct net *net, struct sk_buff *in_skb,
 			  struct netlink_ext_ack *extack)
 {
 	struct cls_bpf_head *head = rtnl_dereference(tp->root);
+	bool is_bpf, is_ebpf, have_exts = false;
 	struct cls_bpf_prog *oldprog = *arg;
 	struct nlattr *tb[TCA_BPF_MAX + 1];
+	bool bound_to_filter = false;
 	struct cls_bpf_prog *prog;
+	u32 gen_flags = 0;
 	int ret;
 
 	if (tca[TCA_OPTIONS] == NULL)
@@ -504,11 +457,51 @@ static int cls_bpf_change(struct net *net, struct sk_buff *in_skb,
 		goto errout;
 	prog->handle = handle;
 
-	ret = cls_bpf_set_parms(net, tp, prog, base, tb, tca[TCA_RATE], flags,
-				extack);
+	is_bpf = tb[TCA_BPF_OPS_LEN] && tb[TCA_BPF_OPS];
+	is_ebpf = tb[TCA_BPF_FD];
+	if ((!is_bpf && !is_ebpf) || (is_bpf && is_ebpf)) {
+		ret = -EINVAL;
+		goto errout_idr;
+	}
+
+	ret = tcf_exts_validate(net, tp, tb, tca[TCA_RATE], &prog->exts,
+				flags, extack);
 	if (ret < 0)
 		goto errout_idr;
 
+	if (tb[TCA_BPF_FLAGS]) {
+		u32 bpf_flags = nla_get_u32(tb[TCA_BPF_FLAGS]);
+
+		if (bpf_flags & ~TCA_BPF_FLAG_ACT_DIRECT) {
+			ret = -EINVAL;
+			goto errout_idr;
+		}
+
+		have_exts = bpf_flags & TCA_BPF_FLAG_ACT_DIRECT;
+	}
+	if (tb[TCA_BPF_FLAGS_GEN]) {
+		gen_flags = nla_get_u32(tb[TCA_BPF_FLAGS_GEN]);
+		if (gen_flags & ~CLS_BPF_SUPPORTED_GEN_FLAGS ||
+		    !tc_flags_valid(gen_flags)) {
+			ret = -EINVAL;
+			goto errout_idr;
+		}
+	}
+
+	prog->exts_integrated = have_exts;
+	prog->gen_flags = gen_flags;
+
+	ret = is_bpf ? cls_bpf_prog_from_ops(tb, prog) :
+		cls_bpf_prog_from_efd(tb, prog, gen_flags, tp);
+	if (ret < 0)
+		goto errout_idr;
+
+	if (tb[TCA_BPF_CLASSID]) {
+		prog->res.classid = nla_get_u32(tb[TCA_BPF_CLASSID]);
+		tcf_bind_filter(tp, &prog->res, base);
+		bound_to_filter = true;
+	}
+
 	ret = cls_bpf_offload(tp, prog, oldprog, extack);
 	if (ret)
 		goto errout_parms;
@@ -530,6 +523,8 @@ static int cls_bpf_change(struct net *net, struct sk_buff *in_skb,
 	return 0;
 
 errout_parms:
+	if (bound_to_filter)
+		tcf_unbind_filter(tp, &prog->res);
 	cls_bpf_free_parms(prog);
 errout_idr:
 	if (!oldprog)