From 61a0cfb008f57ecf7eb28ee762952fb42dc15d15 Mon Sep 17 00:00:00 2001 From: Andre Guedes Date: Wed, 1 Aug 2012 20:34:15 -0300 Subject: Bluetooth: Fix use-after-free bug in SMP 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 --- net/bluetooth/smp.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'net/bluetooth') diff --git a/net/bluetooth/smp.c b/net/bluetooth/smp.c index 901a616c8083..98ffc1b6a6fa 100644 --- a/net/bluetooth/smp.c +++ b/net/bluetooth/smp.c @@ -267,10 +267,10 @@ 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 -- cgit v1.2.3 From cc110922da7e902b62d18641a370fec01a9fa794 Mon Sep 17 00:00:00 2001 From: Vinicius Costa Gomes Date: Thu, 23 Aug 2012 21:32:43 -0300 Subject: Bluetooth: Change signature of smp_conn_security() To make it clear that it may be called from contexts that may not have any knowledge of L2CAP, we change the connection parameter, to receive a hci_conn. This also makes it clear that it is checking the security of the link. Signed-off-by: Vinicius Costa Gomes Signed-off-by: Gustavo Padovan --- include/net/bluetooth/smp.h | 2 +- net/bluetooth/l2cap_core.c | 11 ++++++----- net/bluetooth/l2cap_sock.c | 2 +- net/bluetooth/smp.c | 4 ++-- 4 files changed, 10 insertions(+), 9 deletions(-) (limited to 'net/bluetooth') diff --git a/include/net/bluetooth/smp.h b/include/net/bluetooth/smp.h index ca356a734920..8b27927b2a55 100644 --- a/include/net/bluetooth/smp.h +++ b/include/net/bluetooth/smp.h @@ -136,7 +136,7 @@ struct smp_chan { }; /* SMP Commands */ -int smp_conn_security(struct l2cap_conn *conn, __u8 sec_level); +int smp_conn_security(struct hci_conn *hcon, __u8 sec_level); int smp_sig_channel(struct l2cap_conn *conn, struct sk_buff *skb); int smp_distribute_keys(struct l2cap_conn *conn, __u8 force); int smp_user_confirm_reply(struct hci_conn *conn, u16 mgmt_op, __le32 passkey); diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c index daa149b7003c..4ea1710a4783 100644 --- a/net/bluetooth/l2cap_core.c +++ b/net/bluetooth/l2cap_core.c @@ -1199,14 +1199,15 @@ clean: static void l2cap_conn_ready(struct l2cap_conn *conn) { struct l2cap_chan *chan; + struct hci_conn *hcon = conn->hcon; BT_DBG("conn %p", conn); - if (!conn->hcon->out && conn->hcon->type == LE_LINK) + if (!hcon->out && hcon->type == LE_LINK) l2cap_le_conn_ready(conn); - if (conn->hcon->out && conn->hcon->type == LE_LINK) - smp_conn_security(conn, conn->hcon->pending_sec_level); + if (hcon->out && hcon->type == LE_LINK) + smp_conn_security(hcon, hcon->pending_sec_level); mutex_lock(&conn->chan_lock); @@ -1219,8 +1220,8 @@ static void l2cap_conn_ready(struct l2cap_conn *conn) continue; } - if (conn->hcon->type == LE_LINK) { - if (smp_conn_security(conn, chan->sec_level)) + if (hcon->type == LE_LINK) { + if (smp_conn_security(hcon, chan->sec_level)) l2cap_chan_ready(chan); } else if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED) { diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c index b94abd30e6f9..45cb0b0dd2c7 100644 --- a/net/bluetooth/l2cap_sock.c +++ b/net/bluetooth/l2cap_sock.c @@ -615,7 +615,7 @@ static int l2cap_sock_setsockopt(struct socket *sock, int level, int optname, ch break; } - if (smp_conn_security(conn, sec.level)) + if (smp_conn_security(conn->hcon, sec.level)) break; sk->sk_state = BT_CONFIG; chan->state = BT_CONFIG; diff --git a/net/bluetooth/smp.c b/net/bluetooth/smp.c index 98ffc1b6a6fa..8c225ef349cd 100644 --- a/net/bluetooth/smp.c +++ b/net/bluetooth/smp.c @@ -760,9 +760,9 @@ static u8 smp_cmd_security_req(struct l2cap_conn *conn, struct sk_buff *skb) return 0; } -int smp_conn_security(struct l2cap_conn *conn, __u8 sec_level) +int smp_conn_security(struct hci_conn *hcon, __u8 sec_level) { - struct hci_conn *hcon = conn->hcon; + struct l2cap_conn *conn = hcon->l2cap_data; struct smp_chan *smp = conn->smp_chan; __u8 authreq; -- cgit v1.2.3 From d8343f125710fb596f7a88cd756679f14f4e77b9 Mon Sep 17 00:00:00 2001 From: Vinicius Costa Gomes Date: Thu, 23 Aug 2012 21:32:44 -0300 Subject: Bluetooth: Fix sending a HCI Authorization Request over LE links In the case that the link is already in the connected state and a Pairing request arrives from the mgmt interface, hci_conn_security() would be called but it was not considering LE links. Reported-by: João Paulo Rechi Vita Signed-off-by: Vinicius Costa Gomes Signed-off-by: Gustavo Padovan --- net/bluetooth/hci_conn.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'net/bluetooth') diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c index 5ad7da217474..3c094e78dde9 100644 --- a/net/bluetooth/hci_conn.c +++ b/net/bluetooth/hci_conn.c @@ -29,6 +29,7 @@ #include #include #include +#include static void hci_le_connect(struct hci_conn *conn) { @@ -619,6 +620,9 @@ int hci_conn_security(struct hci_conn *conn, __u8 sec_level, __u8 auth_type) { BT_DBG("hcon %p", conn); + if (conn->type == LE_LINK) + return smp_conn_security(conn, sec_level); + /* For sdp we don't need the link key. */ if (sec_level == BT_SECURITY_SDP) return 1; -- cgit v1.2.3