• Paul Moore's avatar
    selinux: correct locking in selinux_netlbl_socket_connect) · 42d64e1a
    Paul Moore authored
    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: default avatarPaul Moore <pmoore@redhat.com>
    42d64e1a
netlabel.c 12.1 KB