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authorPaul Moore <pmoore@redhat.com>2013-09-26 17:00:46 -0400
committerPaul Moore <pmoore@redhat.com>2013-09-26 17:00:46 -0400
commit42d64e1add3a1ce8a787116036163b8724362145 (patch)
tree9c5bf84e6966d04e4897c483943ed5d5ac805eae
parent7d1db4b242134bb4c7170f4c15491980ac064ac3 (diff)
selinux: correct locking in selinux_netlbl_socket_connect)
The SELinux/NetLabel glue code has a locking bug that affects systems with NetLabel enabled, see the kernel error message below. This patch corrects this problem by converting the bottom half socket lock to a more conventional, and correct for this call-path, lock_sock() call. =============================== [ INFO: suspicious RCU usage. ] 3.11.0-rc3+ #19 Not tainted ------------------------------- net/ipv4/cipso_ipv4.c:1928 suspicious rcu_dereference_protected() usage! other info that might help us debug this: rcu_scheduler_active = 1, debug_locks = 0 2 locks held by ping/731: #0: (slock-AF_INET/1){+.-...}, at: [...] selinux_netlbl_socket_connect #1: (rcu_read_lock){.+.+..}, at: [<...>] netlbl_conn_setattr stack backtrace: CPU: 1 PID: 731 Comm: ping Not tainted 3.11.0-rc3+ #19 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 0000000000000001 ffff88006f659d28 ffffffff81726b6a ffff88003732c500 ffff88006f659d58 ffffffff810e4457 ffff88006b845a00 0000000000000000 000000000000000c ffff880075aa2f50 ffff88006f659d90 ffffffff8169bec7 Call Trace: [<ffffffff81726b6a>] dump_stack+0x54/0x74 [<ffffffff810e4457>] lockdep_rcu_suspicious+0xe7/0x120 [<ffffffff8169bec7>] cipso_v4_sock_setattr+0x187/0x1a0 [<ffffffff8170f317>] netlbl_conn_setattr+0x187/0x190 [<ffffffff8170f195>] ? netlbl_conn_setattr+0x5/0x190 [<ffffffff8131ac9e>] selinux_netlbl_socket_connect+0xae/0xc0 [<ffffffff81303025>] selinux_socket_connect+0x135/0x170 [<ffffffff8119d127>] ? might_fault+0x57/0xb0 [<ffffffff812fb146>] security_socket_connect+0x16/0x20 [<ffffffff815d3ad3>] SYSC_connect+0x73/0x130 [<ffffffff81739a85>] ? sysret_check+0x22/0x5d [<ffffffff810e5e2d>] ? trace_hardirqs_on_caller+0xfd/0x1c0 [<ffffffff81373d4e>] ? trace_hardirqs_on_thunk+0x3a/0x3f [<ffffffff815d52be>] SyS_connect+0xe/0x10 [<ffffffff81739a59>] system_call_fastpath+0x16/0x1b Cc: stable@vger.kernel.org Signed-off-by: Paul Moore <pmoore@redhat.com>
-rw-r--r--security/selinux/netlabel.c6
1 files changed, 2 insertions, 4 deletions
diff --git a/security/selinux/netlabel.c b/security/selinux/netlabel.c
index da4b8b233280..6235d052338b 100644
--- a/security/selinux/netlabel.c
+++ b/security/selinux/netlabel.c
@@ -442,8 +442,7 @@ int selinux_netlbl_socket_connect(struct sock *sk, struct sockaddr *addr)
sksec->nlbl_state != NLBL_CONNLABELED)
return 0;
- local_bh_disable();
- bh_lock_sock_nested(sk);
+ lock_sock(sk);
/* connected sockets are allowed to disconnect when the address family
* is set to AF_UNSPEC, if that is what is happening we want to reset
@@ -464,7 +463,6 @@ int selinux_netlbl_socket_connect(struct sock *sk, struct sockaddr *addr)
sksec->nlbl_state = NLBL_CONNLABELED;
socket_connect_return:
- bh_unlock_sock(sk);
- local_bh_enable();
+ release_sock(sk);
return rc;
}