net_sched: add back BH safety to tcf_lock

Jamal reported that we had to use BH safety after all,
because stats can be updated from BH handler.

Fixes: 3133d5c ("net_sched: remove BH blocking in eight actions")
Fixes: 53df77e ("net_sched: act_skbmod: use RCU in tcf_skbmod_dump()")
Fixes: e97ae74 ("net_sched: act_tunnel_key: use RCU in tunnel_key_dump()")
Fixes: 48b5e5d ("net_sched: act_vlan: use RCU in tcf_vlan_dump()")
Reported-by: Jamal Hadi Salim <[email protected]>
Closes: https://lore.kernel.org/netdev/CAM0EoMmhq66EtVqDEuNik8MVFZqkgxFbMu=fJtbNoYD7YXg4bA@mail.gmail.com/
Signed-off-by: Eric Dumazet <[email protected]>
Signed-off-by: NipaLocal <nipa@local>

Author: edumazet

net/sched/act_connmark.c

@@ -169,10 +169,10 @@ static int tcf_connmark_init(struct net *net, struct nlattr *nla,
 
 	nparms->action = parm->action;
 
-	spin_lock(&ci->tcf_lock);
+	spin_lock_bh(&ci->tcf_lock);
 	goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
 	oparms = rcu_replace_pointer(ci->parms, nparms, lockdep_is_held(&ci->tcf_lock));
-	spin_unlock(&ci->tcf_lock);
+	spin_unlock_bh(&ci->tcf_lock);
 
 	if (goto_ch)
 		tcf_chain_put_by_act(goto_ch);

net/sched/act_csum.c

@@ -101,11 +101,11 @@ static int tcf_csum_init(struct net *net, struct nlattr *nla,
 	params_new->update_flags = parm->update_flags;
 	params_new->action = parm->action;
 
-	spin_lock(&p->tcf_lock);
+	spin_lock_bh(&p->tcf_lock);
 	goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
 	params_new = rcu_replace_pointer(p->params, params_new,
 					 lockdep_is_held(&p->tcf_lock));
-	spin_unlock(&p->tcf_lock);
+	spin_unlock_bh(&p->tcf_lock);
 
 	if (goto_ch)
 		tcf_chain_put_by_act(goto_ch);

net/sched/act_ct.c

@@ -1410,11 +1410,11 @@ static int tcf_ct_init(struct net *net, struct nlattr *nla,
 		goto cleanup;
 
 	params->action = parm->action;
-	spin_lock(&c->tcf_lock);
+	spin_lock_bh(&c->tcf_lock);
 	goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
 	params = rcu_replace_pointer(c->params, params,
 				     lockdep_is_held(&c->tcf_lock));
-	spin_unlock(&c->tcf_lock);
+	spin_unlock_bh(&c->tcf_lock);
 
 	if (goto_ch)
 		tcf_chain_put_by_act(goto_ch);

net/sched/act_ctinfo.c

@@ -258,11 +258,11 @@ static int tcf_ctinfo_init(struct net *net, struct nlattr *nla,
 
 	cp_new->action = actparm->action;
 
-	spin_lock(&ci->tcf_lock);
+	spin_lock_bh(&ci->tcf_lock);
 	goto_ch = tcf_action_set_ctrlact(*a, actparm->action, goto_ch);
 	cp_new = rcu_replace_pointer(ci->params, cp_new,
 				     lockdep_is_held(&ci->tcf_lock));
-	spin_unlock(&ci->tcf_lock);
+	spin_unlock_bh(&ci->tcf_lock);
 
 	if (goto_ch)
 		tcf_chain_put_by_act(goto_ch);

net/sched/act_mpls.c

@@ -296,10 +296,10 @@ static int tcf_mpls_init(struct net *net, struct nlattr *nla,
 					     htons(ETH_P_MPLS_UC));
 	p->action = parm->action;
 
-	spin_lock(&m->tcf_lock);
+	spin_lock_bh(&m->tcf_lock);
 	goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
 	p = rcu_replace_pointer(m->mpls_p, p, lockdep_is_held(&m->tcf_lock));
-	spin_unlock(&m->tcf_lock);
+	spin_unlock_bh(&m->tcf_lock);
 
 	if (goto_ch)
 		tcf_chain_put_by_act(goto_ch);

net/sched/act_nat.c

@@ -95,10 +95,10 @@ static int tcf_nat_init(struct net *net, struct nlattr *nla, struct nlattr *est,
 
 	p = to_tcf_nat(*a);
 
-	spin_lock(&p->tcf_lock);
+	spin_lock_bh(&p->tcf_lock);
 	goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
 	oparm = rcu_replace_pointer(p->parms, nparm, lockdep_is_held(&p->tcf_lock));
-	spin_unlock(&p->tcf_lock);
+	spin_unlock_bh(&p->tcf_lock);
 
 	if (goto_ch)
 		tcf_chain_put_by_act(goto_ch);

net/sched/act_pedit.c

@@ -280,10 +280,10 @@ static int tcf_pedit_init(struct net *net, struct nlattr *nla,
 
 	p = to_pedit(*a);
 	nparms->action = parm->action;
-	spin_lock(&p->tcf_lock);
+	spin_lock_bh(&p->tcf_lock);
 	goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
 	oparms = rcu_replace_pointer(p->parms, nparms, 1);
-	spin_unlock(&p->tcf_lock);
+	spin_unlock_bh(&p->tcf_lock);
 
 	if (oparms)
 		call_rcu(&oparms->rcu, tcf_pedit_cleanup_rcu);

net/sched/act_skbedit.c

@@ -261,11 +261,11 @@ static int tcf_skbedit_init(struct net *net, struct nlattr *nla,
 		params_new->mask = *mask;
 
 	params_new->action = parm->action;
-	spin_lock(&d->tcf_lock);
+	spin_lock_bh(&d->tcf_lock);
 	goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
 	params_new = rcu_replace_pointer(d->params, params_new,
 					 lockdep_is_held(&d->tcf_lock));
-	spin_unlock(&d->tcf_lock);
+	spin_unlock_bh(&d->tcf_lock);
 	if (params_new)
 		kfree_rcu(params_new, rcu);
 	if (goto_ch)

net/sched/act_skbmod.c

@@ -194,7 +194,7 @@ static int tcf_skbmod_init(struct net *net, struct nlattr *nla,
 	p->flags = lflags;
 	p->action = parm->action;
 	if (ovr)
-		spin_lock(&d->tcf_lock);
+		spin_lock_bh(&d->tcf_lock);
 	/* Protected by tcf_lock if overwriting existing action. */
 	goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
 	p_old = rcu_dereference_protected(d->skbmod_p, 1);
@@ -208,7 +208,7 @@ static int tcf_skbmod_init(struct net *net, struct nlattr *nla,
 
 	rcu_assign_pointer(d->skbmod_p, p);
 	if (ovr)
-		spin_unlock(&d->tcf_lock);
+		spin_unlock_bh(&d->tcf_lock);
 
 	if (p_old)
 		kfree_rcu(p_old, rcu);

net/sched/act_tunnel_key.c

@@ -531,11 +531,11 @@ static int tunnel_key_init(struct net *net, struct nlattr *nla,
 	params_new->tcft_enc_metadata = metadata;
 
 	params_new->action = parm->action;
-	spin_lock(&t->tcf_lock);
+	spin_lock_bh(&t->tcf_lock);
 	goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
 	params_new = rcu_replace_pointer(t->params, params_new,
 					 lockdep_is_held(&t->tcf_lock));
-	spin_unlock(&t->tcf_lock);
+	spin_unlock_bh(&t->tcf_lock);
 	tunnel_key_release_params(params_new);
 	if (goto_ch)
 		tcf_chain_put_by_act(goto_ch);