From 94d4ef0c2b3e6c799f78d223e233254a870c4559 Mon Sep 17 00:00:00 2001 From: David Howells Date: Wed, 5 Oct 2011 12:19:19 +0100 Subject: [PATCH] SELinux: Fix RCU deref check warning in sel_netport_insert() Fix the following bug in sel_netport_insert() where rcu_dereference() should be rcu_dereference_protected() as sel_netport_lock is held. =================================================== [ INFO: suspicious rcu_dereference_check() usage. ] --------------------------------------------------- security/selinux/netport.c:127 invoked rcu_dereference_check() without protection! other info that might help us debug this: rcu_scheduler_active = 1, debug_locks = 0 1 lock held by ossec-rootcheck/3323: #0: (sel_netport_lock){+.....}, at: [] sel_netport_sid+0xbb/0x226 stack backtrace: Pid: 3323, comm: ossec-rootcheck Not tainted 3.1.0-rc8-fsdevel+ #1095 Call Trace: [] lockdep_rcu_dereference+0xa7/0xb0 [] sel_netport_sid+0x1b7/0x226 [] ? sel_netport_avc_callback+0xbc/0xbc [] selinux_socket_bind+0x115/0x230 [] ? might_fault+0x4e/0x9e [] ? might_fault+0x97/0x9e [] security_socket_bind+0x11/0x13 [] sys_bind+0x56/0x95 [] ? sysret_check+0x27/0x62 [] ? trace_hardirqs_on_caller+0x11e/0x155 [] ? audit_syscall_entry+0x17b/0x1ae [] ? trace_hardirqs_on_thunk+0x3a/0x3f [] system_call_fastpath+0x16/0x1b Signed-off-by: David Howells Acked-by: Eric Dumazet Acked-by: Paul Moore Signed-off-by: Eric Paris --- security/selinux/netport.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/security/selinux/netport.c b/security/selinux/netport.c index 0b62bd112461..7b9eb1faf68b 100644 --- a/security/selinux/netport.c +++ b/security/selinux/netport.c @@ -123,7 +123,9 @@ static void sel_netport_insert(struct sel_netport *port) if (sel_netport_hash[idx].size == SEL_NETPORT_HASH_BKT_LIMIT) { struct sel_netport *tail; tail = list_entry( - rcu_dereference(sel_netport_hash[idx].list.prev), + rcu_dereference_protected( + sel_netport_hash[idx].list.prev, + lockdep_is_held(&sel_netport_lock)), struct sel_netport, list); list_del_rcu(&tail->list); kfree_rcu(tail, rcu); -- 2.39.5