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authorKuba Pawlak <kubax.t.pawlak@intel.com>2015-10-05 18:44:16 +0200
committerMarcel Holtmann <marcel@holtmann.org>2015-10-25 21:06:39 +0100
commit435c513369768f5840cd57101e398bc450fd26de (patch)
treed908484d1fca94b239db26cc037bc4d097be1904
parent75e34f5cf69bd731d3b7375a786d4a15494fb8c6 (diff)
Bluetooth: Fix locking issue on SCO disconnection
Thread handling SCO disconnection may get preempted in '__sco_sock_close' after dropping a reference to hci_conn but before marking this as NULL in associated struct sco_conn. When execution returs to this thread, this connection will possibly be released, resulting in kernel crash Lock connection before this point. BUG: unable to handle kernel NULL pointer dereference at (null) IP: [<fb770ab9>] __sco_sock_close+0x194/0x1ff [bluetooth] *pdpt = 0000000023da6001 *pde = 0000000000000000 Oops: 0002 [#1] PREEMPT SMP Modules linked in: evdev ecb rfcomm(O) libcomposite usb2380 udc_core bnep(O) btusb(O) btbcm(O) cdc_acm btintel(O) bluetooth(O) arc4 uinput hid_multitouch usbhid iwlmvm(O) hide Pid: 984, comm: bluetooth Tainted: G O 3.8.0-115.1-plk-adaptation-byt-ivi-brd #1 EIP: 0060:[<fb770ab9>] EFLAGS: 00010282 CPU: 2 EIP is at __sco_sock_close+0x194/0x1ff [bluetooth] EAX: 00000000 EBX: e49d7600 ECX: ef1ec3c2 EDX: 000000c3 ESI: e4c12000 EDI: 00000000 EBP: ef1edf5c ESP: ef1edf4c DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068 CR0: 80050033 CR2: 00000000 CR3: 23da7000 CR4: 001007f0 DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000 DR6: ffff0ff0 DR7: 00000400 Process bluetooth (pid: 984, ti=ef1ec000 task=e47f2550 task.ti=ef1ec000) Stack: e4c120d0 e49d7600 00000000 08421a40 ef1edf70 fb770b7a 00000002 e8a4cc80 08421a40 ef1ec000 c12966b1 00000001 00000000 0000000b 084954c8 c1296b6c 0000001b 00000002 0000001b 00000002 00000000 00000002 b2524880 00000046 Call Trace: [<fb770b7a>] ? sco_sock_shutdown+0x56/0x95 [bluetooth] [<c12966b1>] ? sys_shutdown+0x37/0x53 [<c1296b6c>] ? sys_socketcall+0x12e/0x1be [<c134ae7e>] ? sysenter_do_call+0x12/0x26 [<c1340000>] ? ip_vs_control_net_cleanup+0x46/0xb1 Code: e8 90 6b 8c c5 f6 05 72 5d 78 fb 04 74 17 8b 46 08 50 56 68 0a fd 77 fb 68 60 5d 78 fb e8 68 95 9e c5 83 c4 10 8b 83 fc 01 00 00 <c7> 00 00 00 00 00 eb 32 ba 68 00 00 0b EIP: [<fb770ab9>] __sco_sock_close+0x194/0x1ff [bluetooth] SS:ESP 0068:ef1edf4c CR2: 0000000000000000 ---[ end trace 47fa2f55a9544e69 ]--- Signed-off-by: Kuba Pawlak <kubax.t.pawlak@intel.com> Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
-rw-r--r--net/bluetooth/sco.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/net/bluetooth/sco.c b/net/bluetooth/sco.c
index e21c53b08da4..09051e4cbade 100644
--- a/net/bluetooth/sco.c
+++ b/net/bluetooth/sco.c
@@ -416,8 +416,10 @@ static void __sco_sock_close(struct sock *sk)
if (sco_pi(sk)->conn->hcon) {
sk->sk_state = BT_DISCONN;
sco_sock_set_timer(sk, SCO_DISCONN_TIMEOUT);
+ sco_conn_lock(sco_pi(sk)->conn);
hci_conn_drop(sco_pi(sk)->conn->hcon);
sco_pi(sk)->conn->hcon = NULL;
+ sco_conn_unlock(sco_pi(sk)->conn);
} else
sco_chan_del(sk, ECONNRESET);
break;