| Message ID | 20200219101626.31943-1-frextrite@gmail.com |
|---|---|
| State | Not Applicable |
| Delegated to: | Pablo Neira |
| Headers | show |
| Series | netfilter: ipt_CLUSTERIP: Pass lockdep expression to RCU lists | expand |
On Wed, Feb 19, 2020 at 03:46:27PM +0530, Amol Grover wrote: > cn->configs is traversed using list_for_each_entry_rcu > outside an RCU read-side critical section but under the protection > of cn->lock. > > Hence, add corresponding lockdep expression to silence false-positive > warnings, and harden RCU lists. > > Signed-off-by: Amol Grover <frextrite@gmail.com> > --- > net/ipv4/netfilter/ipt_CLUSTERIP.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/net/ipv4/netfilter/ipt_CLUSTERIP.c b/net/ipv4/netfilter/ipt_CLUSTERIP.c > index 6bdb1ab8af61..df856ff835b7 100644 > --- a/net/ipv4/netfilter/ipt_CLUSTERIP.c > +++ b/net/ipv4/netfilter/ipt_CLUSTERIP.c > @@ -139,7 +139,8 @@ __clusterip_config_find(struct net *net, __be32 clusterip) > struct clusterip_config *c; > struct clusterip_net *cn = clusterip_pernet(net); > > - list_for_each_entry_rcu(c, &cn->configs, list) { > + list_for_each_entry_rcu(c, &cn->configs, list, > + lockdep_is_held(&cn->lock)) { bh is disabled before calling __clusterip_config_find(), then rcu_read_lock_any_held() evaluates true. Are you sure this really results in a WARN_ON splat?
diff --git a/net/ipv4/netfilter/ipt_CLUSTERIP.c b/net/ipv4/netfilter/ipt_CLUSTERIP.c index 6bdb1ab8af61..df856ff835b7 100644 --- a/net/ipv4/netfilter/ipt_CLUSTERIP.c +++ b/net/ipv4/netfilter/ipt_CLUSTERIP.c @@ -139,7 +139,8 @@ __clusterip_config_find(struct net *net, __be32 clusterip) struct clusterip_config *c; struct clusterip_net *cn = clusterip_pernet(net); - list_for_each_entry_rcu(c, &cn->configs, list) { + list_for_each_entry_rcu(c, &cn->configs, list, + lockdep_is_held(&cn->lock)) { if (c->clusterip == clusterip) return c; } @@ -194,7 +195,8 @@ clusterip_netdev_event(struct notifier_block *this, unsigned long event, struct clusterip_config *c; spin_lock_bh(&cn->lock); - list_for_each_entry_rcu(c, &cn->configs, list) { + list_for_each_entry_rcu(c, &cn->configs, list, + lockdep_is_held(&cn->lock)) { switch (event) { case NETDEV_REGISTER: if (!strcmp(dev->name, c->ifname)) {
cn->configs is traversed using list_for_each_entry_rcu outside an RCU read-side critical section but under the protection of cn->lock. Hence, add corresponding lockdep expression to silence false-positive warnings, and harden RCU lists. Signed-off-by: Amol Grover <frextrite@gmail.com> --- net/ipv4/netfilter/ipt_CLUSTERIP.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)