Return-Path: From: Arkadiusz Lichwa To: linux-bluetooth@vger.kernel.org Cc: Arek Lichwa Subject: [PATCH] Bluetooth: Fix NULL pointer dereference in mgmt context Date: Thu, 22 Sep 2016 14:08:05 +0200 Message-Id: <20160922120805.30690-1-arek.lichwa@gmail.com> Sender: linux-bluetooth-owner@vger.kernel.org List-ID: From: Arek Lichwa Adds missing callback assignment to cmd_complete in pending management command context. Dump path involves security procedure performed on legacy (pre-SSP) devices with service security requirements set to HIGH (16digits PIN). It fails when shorter PIN is delivered by user. [ 1.517950] Bluetooth: PIN code is not 16 bytes long [ 1.518491] BUG: unable to handle kernel NULL pointer dereference at (null) [ 1.518584] IP: [< (null)>] (null) [ 1.518584] PGD 9e08067 PUD 9fdf067 PMD 0 [ 1.518584] Oops: 0010 [#1] SMP [ 1.518584] Modules linked in: [ 1.518584] CPU: 0 PID: 1002 Comm: kworker/u3:2 Not tainted 4.8.0-rc6-354649-gaf4168c #16 [ 1.518584] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.9.3-20160701_074356-anatol 04/01/2014 [ 1.518584] Workqueue: hci0 hci_rx_work [ 1.518584] task: ffff880009ce14c0 task.stack: ffff880009e10000 [ 1.518584] RIP: 0010:[<0000000000000000>] [< (null)>] (null) [ 1.518584] RSP: 0018:ffff880009e13bc8 EFLAGS: 00010293 [ 1.518584] RAX: 0000000000000000 RBX: ffff880009eed100 RCX: 0000000000000006 [ 1.518584] RDX: ffff880009ddc000 RSI: 0000000000000000 RDI: ffff880009eed100 [ 1.518584] RBP: ffff880009e13be0 R08: 0000000000000000 R09: 0000000000000001 [ 1.518584] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 1.518584] R13: ffff880009e13ccd R14: ffff880009ddc000 R15: ffff880009ddc010 [ 1.518584] FS: 0000000000000000(0000) GS:ffff88000bc00000(0000) knlGS:0000000000000000 [ 1.518584] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 1.518584] CR2: 0000000000000000 CR3: 0000000009fdd000 CR4: 00000000000006f0 [ 1.518584] Stack: [ 1.518584] ffffffff81909808 ffff880009e13cce ffff880009e0d40b ffff880009e13c68 [ 1.518584] ffffffff818f428d 00000000024000c0 ffff880009e13c08 ffffffff810ca903 [ 1.518584] ffff880009e13c48 ffffffff811ade34 ffffffff8178c31f ffff880009ee6200 [ 1.518584] Call Trace: [ 1.518584] [] ? mgmt_pin_code_neg_reply_complete+0x38/0x60 [ 1.518584] [] hci_cmd_complete_evt+0x69d/0x3200 [ 1.518584] [] ? rcu_read_lock_sched_held+0x53/0x60 [ 1.518584] [] ? kmem_cache_alloc+0x1a4/0x200 [ 1.518584] [] ? skb_clone+0x4f/0xa0 [ 1.518584] [] hci_event_packet+0x8e1/0x28e0 [ 1.518584] [] ? _raw_spin_unlock_irqrestore+0x31/0x50 [ 1.518584] [] ? trace_hardirqs_on_caller+0xee/0x1b0 [ 1.518584] [] hci_rx_work+0x1e1/0x5b0 [ 1.518584] [] ? process_one_work+0x1ed/0x6b0 [ 1.518584] [] process_one_work+0x268/0x6b0 [ 1.518584] [] ? process_one_work+0x1ed/0x6b0 [ 1.518584] [] worker_thread+0x43/0x4e0 [ 1.518584] [] ? process_one_work+0x6b0/0x6b0 [ 1.518584] [] ? process_one_work+0x6b0/0x6b0 [ 1.518584] [] kthread+0xdf/0x100 [ 1.518584] [] ret_from_fork+0x1f/0x40 [ 1.518584] [] ? kthread_create_on_node+0x210/0x210 Signed-off-by: Arek Lichwa --- net/bluetooth/mgmt.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c index 7b2bac4..63f42f4 100644 --- a/net/bluetooth/mgmt.c +++ b/net/bluetooth/mgmt.c @@ -2541,6 +2541,8 @@ static int send_pin_code_neg_reply(struct sock *sk, struct hci_dev *hdev, if (!cmd) return -ENOMEM; + cmd->cmd_complete = addr_cmd_complete; + err = hci_send_cmd(hdev, HCI_OP_PIN_CODE_NEG_REPLY, sizeof(cp->addr.bdaddr), &cp->addr.bdaddr); if (err < 0) -- 2.10.0