ipmr: fix error path when ipmr_new_table fails

commit 0bbbf0e7d0 ("ipmr, ip6mr: Unite creation of new mr_table")
refactored ipmr_new_table, so that it now returns NULL when
mr_table_alloc fails. Unfortunately, all callers of ipmr_new_table
expect an ERR_PTR.

This can result in NULL deref, for example when ipmr_rules_exit calls
ipmr_free_table with NULL net->ipv4.mrt in the
!CONFIG_IP_MROUTE_MULTIPLE_TABLES version.

This patch makes mr_table_alloc return errors, and changes
ip6mr_new_table and its callers to return/expect error pointers as
well. It also removes the version of mr_table_alloc defined under
!CONFIG_IP_MROUTE_COMMON, since it is never used.

Fixes: 0bbbf0e7d0 ("ipmr, ip6mr: Unite creation of new mr_table")
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Sabrina Dubroca 2018-06-05 15:02:00 +02:00 committed by David S. Miller
parent 848235edb5
commit e783bb00ad
3 changed files with 17 additions and 19 deletions

View file

@ -307,16 +307,6 @@ static inline void vif_device_init(struct vif_device *v,
{
}
static inline void *
mr_table_alloc(struct net *net, u32 id,
struct mr_table_ops *ops,
void (*expire_func)(struct timer_list *t),
void (*table_set)(struct mr_table *mrt,
struct net *net))
{
return NULL;
}
static inline void *mr_mfc_find_parent(struct mr_table *mrt,
void *hasharg, int parent)
{

View file

@ -35,17 +35,19 @@ mr_table_alloc(struct net *net, u32 id,
struct net *net))
{
struct mr_table *mrt;
int err;
mrt = kzalloc(sizeof(*mrt), GFP_KERNEL);
if (!mrt)
return NULL;
return ERR_PTR(-ENOMEM);
mrt->id = id;
write_pnet(&mrt->net, net);
mrt->ops = *ops;
if (rhltable_init(&mrt->mfc_hash, mrt->ops.rht_params)) {
err = rhltable_init(&mrt->mfc_hash, mrt->ops.rht_params);
if (err) {
kfree(mrt);
return NULL;
return ERR_PTR(err);
}
INIT_LIST_HEAD(&mrt->mfc_cache_list);
INIT_LIST_HEAD(&mrt->mfc_unres_queue);

View file

@ -228,8 +228,8 @@ static int __net_init ip6mr_rules_init(struct net *net)
INIT_LIST_HEAD(&net->ipv6.mr6_tables);
mrt = ip6mr_new_table(net, RT6_TABLE_DFLT);
if (!mrt) {
err = -ENOMEM;
if (IS_ERR(mrt)) {
err = PTR_ERR(mrt);
goto err1;
}
@ -302,8 +302,13 @@ static int ip6mr_fib_lookup(struct net *net, struct flowi6 *flp6,
static int __net_init ip6mr_rules_init(struct net *net)
{
net->ipv6.mrt6 = ip6mr_new_table(net, RT6_TABLE_DFLT);
return net->ipv6.mrt6 ? 0 : -ENOMEM;
struct mr_table *mrt;
mrt = ip6mr_new_table(net, RT6_TABLE_DFLT);
if (IS_ERR(mrt))
return PTR_ERR(mrt);
net->ipv6.mrt6 = mrt;
return 0;
}
static void __net_exit ip6mr_rules_exit(struct net *net)
@ -1758,8 +1763,9 @@ int ip6_mroute_setsockopt(struct sock *sk, int optname, char __user *optval, uns
rtnl_lock();
ret = 0;
if (!ip6mr_new_table(net, v))
ret = -ENOMEM;
mrt = ip6mr_new_table(net, v);
if (IS_ERR(mrt))
ret = PTR_ERR(mrt);
else
raw6_sk(sk)->ip6mr_table = v;
rtnl_unlock();