From c9b7b9793764b171a118d049d4b721a7f5d8ac82 Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Fri, 25 Apr 2008 15:03:39 -0400 Subject: SELinux: Fix a RCU free problem with the netport cache The netport cache doesn't free resources in a manner which is safe or orderly. This patch fixes this by adding in a missing call to rcu_dereference() in sel_netport_insert() as well as some general cleanup throughout the file. Signed-off-by: Paul Moore Signed-off-by: James Morris --- security/selinux/netport.c | 40 ++++++++++++++++++---------------------- 1 file changed, 18 insertions(+), 22 deletions(-) (limited to 'security') diff --git a/security/selinux/netport.c b/security/selinux/netport.c index 68ede3c498a..90b4cff7c35 100644 --- a/security/selinux/netport.c +++ b/security/selinux/netport.c @@ -114,8 +114,7 @@ static struct sel_netport *sel_netport_find(u8 protocol, u16 pnum) idx = sel_netport_hashfn(pnum); list_for_each_entry_rcu(port, &sel_netport_hash[idx].list, list) - if (port->psec.port == pnum && - port->psec.protocol == protocol) + if (port->psec.port == pnum && port->psec.protocol == protocol) return port; return NULL; @@ -126,11 +125,10 @@ static struct sel_netport *sel_netport_find(u8 protocol, u16 pnum) * @port: the new port record * * Description: - * Add a new port record to the network address hash table. Returns zero on - * success, negative values on failure. + * Add a new port record to the network address hash table. * */ -static int sel_netport_insert(struct sel_netport *port) +static void sel_netport_insert(struct sel_netport *port) { unsigned int idx; @@ -140,13 +138,13 @@ static int sel_netport_insert(struct sel_netport *port) list_add_rcu(&port->list, &sel_netport_hash[idx].list); if (sel_netport_hash[idx].size == SEL_NETPORT_HASH_BKT_LIMIT) { struct sel_netport *tail; - tail = list_entry(port->list.prev, struct sel_netport, list); - list_del_rcu(port->list.prev); + tail = list_entry( + rcu_dereference(sel_netport_hash[idx].list.prev), + struct sel_netport, list); + list_del_rcu(&tail->list); call_rcu(&tail->rcu, sel_netport_free); } else sel_netport_hash[idx].size++; - - return 0; } /** @@ -163,7 +161,7 @@ static int sel_netport_insert(struct sel_netport *port) */ static int sel_netport_sid_slow(u8 protocol, u16 pnum, u32 *sid) { - int ret; + int ret = -ENOMEM; struct sel_netport *port; struct sel_netport *new = NULL; @@ -171,23 +169,20 @@ static int sel_netport_sid_slow(u8 protocol, u16 pnum, u32 *sid) port = sel_netport_find(protocol, pnum); if (port != NULL) { *sid = port->psec.sid; - ret = 0; - goto out; + spin_unlock_bh(&sel_netport_lock); + return 0; } new = kzalloc(sizeof(*new), GFP_ATOMIC); - if (new == NULL) { - ret = -ENOMEM; + if (new == NULL) goto out; - } - ret = security_port_sid(protocol, pnum, &new->psec.sid); + ret = security_port_sid(protocol, pnum, sid); if (ret != 0) goto out; + new->psec.port = pnum; new->psec.protocol = protocol; - ret = sel_netport_insert(new); - if (ret != 0) - goto out; - *sid = new->psec.sid; + new->psec.sid = *sid; + sel_netport_insert(new); out: spin_unlock_bh(&sel_netport_lock); @@ -239,11 +234,12 @@ int sel_netport_sid(u8 protocol, u16 pnum, u32 *sid) static void sel_netport_flush(void) { unsigned int idx; - struct sel_netport *port; + struct sel_netport *port, *port_tmp; spin_lock_bh(&sel_netport_lock); for (idx = 0; idx < SEL_NETPORT_HASH_SIZE; idx++) { - list_for_each_entry(port, &sel_netport_hash[idx].list, list) { + list_for_each_entry_safe(port, port_tmp, + &sel_netport_hash[idx].list, list) { list_del_rcu(&port->list); call_rcu(&port->rcu, sel_netport_free); } -- cgit v1.2.3