From e783bb00ad86d9d1f01d9d3a750713070036358e Mon Sep 17 00:00:00 2001 From: Sabrina Dubroca Date: Tue, 5 Jun 2018 15:02:00 +0200 Subject: ipmr: fix error path when ipmr_new_table fails 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 Signed-off-by: David S. Miller --- net/ipv6/ip6mr.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) (limited to 'net/ipv6') diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c index 5c57374850b3..058fc05e5708 100644 --- a/net/ipv6/ip6mr.c +++ b/net/ipv6/ip6mr.c @@ -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(); -- cgit v1.2.1