Hi Johan, On Tue, Jun 05, 2012 at 02:20:41PM +0800, Johan Hedberg wrote: > From: Johan Hedberg <johan.hedberg@xxxxxxxxx> > > In the following scenario conn->hchan is not set when l2cap_conn_del is > called: > > < HCI Command: LE Create Connection (0x08|0x000d) plen 25 > bdaddr xx:xx:xx:xx:xx:xx type 0 > > HCI Event: Command Status (0x0f) plen 4 > LE Create Connection (0x08|0x000d) status 0x00 ncmd 1 > > HCI Event: LE Meta Event (0x3e) plen 19 > LE Connection Complete > status 0x00 handle 64, role master > bdaddr xx:xx:xx:xx:xx:xx (Public) > < ACL data: handle 64 flags 0x00 dlen 11 > SMP: Pairing Request (0x01) > capability 0x04 oob 0x00 auth req 0x01 > max key size 0x10 init key dist 0x00 resp key dist 0x01 > Capability: KeyboardDisplay (OOB data not present) > Authentication: Bonding (No MITM Protection) > Initiator Key Distribution: > Responder Key Distribution: LTK > > HCI Event: Number of Completed Packets (0x13) plen 5 > handle 64 packets 1 > < HCI Command: Disconnect (0x01|0x0006) plen 3 > handle 64 reason 0x13 > Reason: Remote User Terminated Connection > > HCI Event: Command Status (0x0f) plen 4 > Disconnect (0x01|0x0006) status 0x00 ncmd 1 > > HCI Event: Disconn Complete (0x05) plen 4 > status 0x00 handle 64 reason 0x22 > Reason: LMP Response Timeout > > This results in the following crash: > > BUG: unable to handle kernel NULL pointer dereference at 00000004 > IP: [<c123f9e5>] hci_chan_del+0x41/0x6e > *pde = 00000000 > Oops: 0002 [#1] SMP > Modules linked in: > > Pid: 32, comm: kworker/u:3 Not tainted 3.5.0-rc1+ #322 Bochs Bochs > EIP: 0060:[<c123f9e5>] EFLAGS: 00010246 CPU: 1 > EIP is at hci_chan_del+0x41/0x6e > EAX: 00200909 EBX: f5dd2280 ECX: 00000000 EDX: 00000000 > ESI: f5d5edc4 EDI: f6201e60 EBP: f6201e50 ESP: f6201e48 > DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068 > CR0: 8005003b CR2: 00000004 CR3: 35f12000 CR4: 00000690 > DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000 > DR6: ffff0ff0 DR7: 00000400 > Process kworker/u:3 (pid: 32, ti=f6200000 task=f686e730 task.ti=f6200000) > Stack: > f5d5ef00 f6201e60 f6201e88 c12507b3 f62e6000 c12507b3 c1245fad 0000000c > f5d5ef94 00000026 f5d5ef9c f5d5edc4 f6917800 f62e6000 00000022 f6201e98 > f6201ea8 c125440b f6201eb8 c125440b c124963d f6254622 f62e6000 f6201eb8 > Call Trace: > [<c12507b3>] l2cap_conn_del+0xef/0x135 > [<c12507b3>] ? l2cap_conn_del+0xef/0x135 > [<c1245fad>] ? mgmt_event+0x95/0xa6 > [<c125440b>] l2cap_disconn_cfm+0x49/0x57 > [<c125440b>] ? l2cap_disconn_cfm+0x49/0x57 > [<c124963d>] ? user_confirm_reply+0x7d/0x7d > [<c124446c>] hci_event_packet+0x33e/0x1cce > [<c124446c>] ? hci_event_packet+0x33e/0x1cce > [<c11e1aaa>] ? __kfree_skb+0x6a/0x6d > [<c11e1af9>] ? kfree_skb+0x25/0x27 > [<c124be14>] ? hci_send_to_sock+0x168/0x174 > [<c123b66c>] hci_rx_work+0xf3/0x347 > [<c123b66c>] ? hci_rx_work+0xf3/0x347 > [<c123b9a7>] ? hci_cmd_work+0xb4/0xd8 > > This patch fixes this issue by adding a NULL check for conn->hchan. > > Signed-off-by: Johan Hedberg <johan.hedberg@xxxxxxxxx> > --- > net/bluetooth/l2cap_core.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c > index f9bffe3..62df491 100644 > --- a/net/bluetooth/l2cap_core.c > +++ b/net/bluetooth/l2cap_core.c > @@ -1295,7 +1295,8 @@ static void l2cap_conn_del(struct hci_conn *hcon, int err) > > mutex_unlock(&conn->chan_lock); > > - hci_chan_del(conn->hchan); > + if (conn->hchan) > + hci_chan_del(conn->hchan); Is this SMP - related bug? Shall we check rather for LE/SMP stuff? Best regards Andrei Emeltchenko -- To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
