4.17-stable review patch. If anyone has any objections, please let me know.
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From: Sabrina Dubroca sd@queasysnail.net
[ Upstream commit e783bb00ad86d9d1f01d9d3a750713070036358e ]
commit 0bbbf0e7d0e7 ("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: 0bbbf0e7d0e7 ("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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- include/linux/mroute_base.h | 10 ---------- net/ipv4/ipmr_base.c | 8 +++++--- net/ipv6/ip6mr.c | 18 ++++++++++++------ 3 files changed, 17 insertions(+), 19 deletions(-)
--- a/include/linux/mroute_base.h +++ b/include/linux/mroute_base.h @@ -307,16 +307,6 @@ static inline void vif_device_init(struc { }
-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) { --- a/net/ipv4/ipmr_base.c +++ b/net/ipv4/ipmr_base.c @@ -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); --- a/net/ipv6/ip6mr.c +++ b/net/ipv6/ip6mr.c @@ -227,8 +227,8 @@ static int __net_init ip6mr_rules_init(s 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; }
@@ -301,8 +301,13 @@ static int ip6mr_fib_lookup(struct net *
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) @@ -1757,8 +1762,9 @@ int ip6_mroute_setsockopt(struct sock *s
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();