Messages in this thread Patch in this message | | | Date | Tue, 03 Jan 2012 14:33:01 -0800 | From | Greg KH <> | Subject | [28/75] SELinux: Fix RCU deref check warning in sel_netport_insert() |
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3.1-stable review patch. If anyone has any objections, please let me know.
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From: David Howells <dhowells@redhat.com>
commit 50345f1ea9cda4618d9c26e590a97ecd4bc7ac75 upstream.
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: [<ffffffff8117d775>] sel_netport_sid+0xbb/0x226
stack backtrace: Pid: 3323, comm: ossec-rootcheck Not tainted 3.1.0-rc8-fsdevel+ #1095 Call Trace: [<ffffffff8105cfb7>] lockdep_rcu_dereference+0xa7/0xb0 [<ffffffff8117d871>] sel_netport_sid+0x1b7/0x226 [<ffffffff8117d6ba>] ? sel_netport_avc_callback+0xbc/0xbc [<ffffffff8117556c>] selinux_socket_bind+0x115/0x230 [<ffffffff810a5388>] ? might_fault+0x4e/0x9e [<ffffffff810a53d1>] ? might_fault+0x97/0x9e [<ffffffff81171cf4>] security_socket_bind+0x11/0x13 [<ffffffff812ba967>] sys_bind+0x56/0x95 [<ffffffff81380dac>] ? sysret_check+0x27/0x62 [<ffffffff8105b767>] ? trace_hardirqs_on_caller+0x11e/0x155 [<ffffffff81076fcd>] ? audit_syscall_entry+0x17b/0x1ae [<ffffffff811b5eae>] ? trace_hardirqs_on_thunk+0x3a/0x3f [<ffffffff81380d7b>] system_call_fastpath+0x16/0x1b
Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Paul Moore <paul@paul-moore.com> Acked-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: James Morris <jmorris@namei.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
--- security/selinux/netport.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
--- a/security/selinux/netport.c +++ b/security/selinux/netport.c @@ -123,7 +123,9 @@ static void sel_netport_insert(struct se 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);
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