From 222616daa324e7a7c911d8f513181417b55ba2df Mon Sep 17 00:00:00 2001 From: Andre Guedes Date: Wed, 1 Aug 2012 20:34:15 -0300 Subject: [PATCH] Bluetooth: Fix use-after-free bug in SMP commit 61a0cfb008f57ecf7eb28ee762952fb42dc15d15 upstream. If SMP fails, we should always cancel security_timer delayed work. Otherwise, security_timer function may run after l2cap_conn object has been freed. This patch fixes the following warning reported by ODEBUG: WARNING: at lib/debugobjects.c:261 debug_print_object+0x7c/0x8d() Hardware name: Bochs ODEBUG: free active (active state 0) object type: timer_list hint: delayed_work_timer_fn+0x0/0x27 Modules linked in: btusb bluetooth Pid: 440, comm: kworker/u:2 Not tainted 3.5.0-rc1+ #4 Call Trace: [] ? free_obj_work+0x4a/0x7f [] warn_slowpath_common+0x7e/0x97 [] warn_slowpath_fmt+0x41/0x43 [] debug_print_object+0x7c/0x8d [] ? __queue_work+0x241/0x241 [] debug_check_no_obj_freed+0x92/0x159 [] slab_free_hook+0x6f/0x77 [] ? l2cap_conn_del+0x148/0x157 [bluetooth] [] kfree+0x59/0xac [] l2cap_conn_del+0x148/0x157 [bluetooth] [] l2cap_recv_frame+0xa77/0xfa4 [bluetooth] [] ? trace_hardirqs_on_caller+0x112/0x1ad [] l2cap_recv_acldata+0xe2/0x264 [bluetooth] [] hci_rx_work+0x235/0x33c [bluetooth] [] ? process_one_work+0x126/0x2fe [] process_one_work+0x185/0x2fe [] ? process_one_work+0x126/0x2fe [] ? lock_acquired+0x1b5/0x1cf [] ? le_scan_work+0x11d/0x11d [bluetooth] [] ? spin_lock_irq+0x9/0xb [] worker_thread+0xcf/0x175 [] ? rescuer_thread+0x175/0x175 [] kthread+0x95/0x9d [] kernel_threadi_helper+0x4/0x10 [] ? retint_restore_args+0x13/0x13 [] ? flush_kthread_worker+0xdb/0xdb [] ? gs_change+0x13/0x13 This bug can be reproduced using hctool lecc or l2test tools and bluetoothd not running. Signed-off-by: Andre Guedes Signed-off-by: Gustavo Padovan Signed-off-by: Greg Kroah-Hartman --- net/bluetooth/smp.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/net/bluetooth/smp.c b/net/bluetooth/smp.c index 37df4e9b3896..022596f884f5 100644 --- a/net/bluetooth/smp.c +++ b/net/bluetooth/smp.c @@ -266,10 +266,10 @@ static void smp_failure(struct l2cap_conn *conn, u8 reason, u8 send) mgmt_auth_failed(conn->hcon->hdev, conn->dst, hcon->type, hcon->dst_type, reason); - if (test_and_clear_bit(HCI_CONN_LE_SMP_PEND, &conn->hcon->flags)) { - cancel_delayed_work_sync(&conn->security_timer); + cancel_delayed_work_sync(&conn->security_timer); + + if (test_and_clear_bit(HCI_CONN_LE_SMP_PEND, &conn->hcon->flags)) smp_chan_destroy(conn); - } } #define JUST_WORKS 0x00 -- 2.39.5