[PATCH AUTOSEL 4.4 50/53] Bluetooth: hci_bcsp: Fix memory leak in rx_skb

[PATCH AUTOSEL 4.4 50/53] Bluetooth: hci_bcsp: Fix memory leak in rx_skb

[Sasha Levin]

From: Tomas Bortoli <tomasbortoli@gmail.com>

[ Upstream commit 4ce9146e0370fcd573f0372d9b4e5a211112567c ]

Syzkaller found that it is possible to provoke a memory leak by
never freeing rx_skb in struct bcsp_struct.

Fix by freeing in bcsp_close()

Signed-off-by: Tomas Bortoli <tomasbortoli@gmail.com>
Reported-by: syzbot+98162c885993b72f19c4@syzkaller.appspotmail.com
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/bluetooth/hci_bcsp.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/bluetooth/hci_bcsp.c b/drivers/bluetooth/hci_bcsp.c
index d0b615a932d1..9833b53a8b50 100644
--- a/drivers/bluetooth/hci_bcsp.c
+++ b/drivers/bluetooth/hci_bcsp.c
@@ -729,6 +729,11 @@ static int bcsp_close(struct hci_uart *hu)
 	skb_queue_purge(&bcsp->rel);
 	skb_queue_purge(&bcsp->unrel);
 
+	if (bcsp->rx_skb) {
+		kfree_skb(bcsp->rx_skb);
+		bcsp->rx_skb = NULL;
+	}
+
 	kfree(bcsp);
 	return 0;
 }
-- 
2.20.1

[PATCH AUTOSEL 4.4 51/53] Bluetooth: 6lowpan: search for destination address in all peers

[Sasha Levin]

From: Josua Mayer <josua.mayer@jm0.eu>

[ Upstream commit b188b03270b7f8568fc714101ce82fbf5e811c5a ]

Handle overlooked case where the target address is assigned to a peer
and neither route nor gateway exist.

For one peer, no checks are performed to see if it is meant to receive
packets for a given address.

As soon as there is a second peer however, checks are performed
to deal with routes and gateways for handling complex setups with
multiple hops to a target address.
This logic assumed that no route and no gateway imply that the
destination address can not be reached, which is false in case of a
direct peer.

Acked-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Tested-by: Michael Scott <mike@foundries.io>
Signed-off-by: Josua Mayer <josua.mayer@jm0.eu>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/bluetooth/6lowpan.c | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/net/bluetooth/6lowpan.c b/net/bluetooth/6lowpan.c
index 795ddd8b2f77..4cd6b8d811ff 100644
--- a/net/bluetooth/6lowpan.c
+++ b/net/bluetooth/6lowpan.c
@@ -184,10 +184,16 @@ static inline struct lowpan_peer *peer_lookup_dst(struct lowpan_dev *dev,
 	}
 
 	if (!rt) {
-		nexthop = &lowpan_cb(skb)->gw;
-
-		if (ipv6_addr_any(nexthop))
-			return NULL;
+		if (ipv6_addr_any(&lowpan_cb(skb)->gw)) {
+			/* There is neither route nor gateway,
+			 * probably the destination is a direct peer.
+			 */
+			nexthop = daddr;
+		} else {
+			/* There is a known gateway
+			 */
+			nexthop = &lowpan_cb(skb)->gw;
+		}
 	} else {
 		nexthop = rt6_nexthop(rt, daddr);
 
-- 
2.20.1

[PATCH AUTOSEL 4.4 52/53] Bluetooth: Check state in l2cap_disconnect_rsp

[Sasha Levin]

From: Matias Karhumaa <matias.karhumaa@gmail.com>

[ Upstream commit 28261da8a26f4915aa257d12d506c6ba179d961f ]

Because of both sides doing L2CAP disconnection at the same time, it
was possible to receive L2CAP Disconnection Response with CID that was
already freed. That caused problems if CID was already reused and L2CAP
Connection Request with same CID was sent out. Before this patch kernel
deleted channel context regardless of the state of the channel.

Example where leftover Disconnection Response (frame #402) causes local
device to delete L2CAP channel which was not yet connected. This in
turn confuses remote device's stack because same CID is re-used without
properly disconnecting.

Btmon capture before patch:
** snip **
> ACL Data RX: Handle 43 flags 0x02 dlen 8                #394 [hci1] 10.748949
      Channel: 65 len 4 [PSM 3 mode 0] {chan 2}
      RFCOMM: Disconnect (DISC) (0x43)
         Address: 0x03 cr 1 dlci 0x00
         Control: 0x53 poll/final 1
         Length: 0
         FCS: 0xfd
< ACL Data TX: Handle 43 flags 0x00 dlen 8                #395 [hci1] 10.749062
      Channel: 65 len 4 [PSM 3 mode 0] {chan 2}
      RFCOMM: Unnumbered Ack (UA) (0x63)
         Address: 0x03 cr 1 dlci 0x00
         Control: 0x73 poll/final 1
         Length: 0
         FCS: 0xd7
< ACL Data TX: Handle 43 flags 0x00 dlen 12               #396 [hci1] 10.749073
      L2CAP: Disconnection Request (0x06) ident 17 len 4
        Destination CID: 65
        Source CID: 65
> HCI Event: Number of Completed Packets (0x13) plen 5    #397 [hci1] 10.752391
        Num handles: 1
        Handle: 43
        Count: 1
> HCI Event: Number of Completed Packets (0x13) plen 5    #398 [hci1] 10.753394
        Num handles: 1
        Handle: 43
        Count: 1
> ACL Data RX: Handle 43 flags 0x02 dlen 12               #399 [hci1] 10.756499
      L2CAP: Disconnection Request (0x06) ident 26 len 4
        Destination CID: 65
        Source CID: 65
< ACL Data TX: Handle 43 flags 0x00 dlen 12               #400 [hci1] 10.756548
      L2CAP: Disconnection Response (0x07) ident 26 len 4
        Destination CID: 65
        Source CID: 65
< ACL Data TX: Handle 43 flags 0x00 dlen 12               #401 [hci1] 10.757459
      L2CAP: Connection Request (0x02) ident 18 len 4
        PSM: 1 (0x0001)
        Source CID: 65
> ACL Data RX: Handle 43 flags 0x02 dlen 12               #402 [hci1] 10.759148
      L2CAP: Disconnection Response (0x07) ident 17 len 4
        Destination CID: 65
        Source CID: 65
= bluetoothd: 00:1E:AB:4C:56:54: error updating services: Input/o..   10.759447
> HCI Event: Number of Completed Packets (0x13) plen 5    #403 [hci1] 10.759386
        Num handles: 1
        Handle: 43
        Count: 1
> ACL Data RX: Handle 43 flags 0x02 dlen 12               #404 [hci1] 10.760397
      L2CAP: Connection Request (0x02) ident 27 len 4
        PSM: 3 (0x0003)
        Source CID: 65
< ACL Data TX: Handle 43 flags 0x00 dlen 16               #405 [hci1] 10.760441
      L2CAP: Connection Response (0x03) ident 27 len 8
        Destination CID: 65
        Source CID: 65
        Result: Connection successful (0x0000)
        Status: No further information available (0x0000)
< ACL Data TX: Handle 43 flags 0x00 dlen 27               #406 [hci1] 10.760449
      L2CAP: Configure Request (0x04) ident 19 len 19
        Destination CID: 65
        Flags: 0x0000
        Option: Maximum Transmission Unit (0x01) [mandatory]
          MTU: 1013
        Option: Retransmission and Flow Control (0x04) [mandatory]
          Mode: Basic (0x00)
          TX window size: 0
          Max transmit: 0
          Retransmission timeout: 0
          Monitor timeout: 0
          Maximum PDU size: 0
> HCI Event: Number of Completed Packets (0x13) plen 5    #407 [hci1] 10.761399
        Num handles: 1
        Handle: 43
        Count: 1
> ACL Data RX: Handle 43 flags 0x02 dlen 16               #408 [hci1] 10.762942
      L2CAP: Connection Response (0x03) ident 18 len 8
        Destination CID: 66
        Source CID: 65
        Result: Connection successful (0x0000)
        Status: No further information available (0x0000)
*snip*

Similar case after the patch:
*snip*
> ACL Data RX: Handle 43 flags 0x02 dlen 8            #22702 [hci0] 1664.411056
      Channel: 65 len 4 [PSM 3 mode 0] {chan 3}
      RFCOMM: Disconnect (DISC) (0x43)
         Address: 0x03 cr 1 dlci 0x00
         Control: 0x53 poll/final 1
         Length: 0
         FCS: 0xfd
< ACL Data TX: Handle 43 flags 0x00 dlen 8            #22703 [hci0] 1664.411136
      Channel: 65 len 4 [PSM 3 mode 0] {chan 3}
      RFCOMM: Unnumbered Ack (UA) (0x63)
         Address: 0x03 cr 1 dlci 0x00
         Control: 0x73 poll/final 1
         Length: 0
         FCS: 0xd7
< ACL Data TX: Handle 43 flags 0x00 dlen 12           #22704 [hci0] 1664.411143
      L2CAP: Disconnection Request (0x06) ident 11 len 4
        Destination CID: 65
        Source CID: 65
> HCI Event: Number of Completed Pac.. (0x13) plen 5  #22705 [hci0] 1664.414009
        Num handles: 1
        Handle: 43
        Count: 1
> HCI Event: Number of Completed Pac.. (0x13) plen 5  #22706 [hci0] 1664.415007
        Num handles: 1
        Handle: 43
        Count: 1
> ACL Data RX: Handle 43 flags 0x02 dlen 12           #22707 [hci0] 1664.418674
      L2CAP: Disconnection Request (0x06) ident 17 len 4
        Destination CID: 65
        Source CID: 65
< ACL Data TX: Handle 43 flags 0x00 dlen 12           #22708 [hci0] 1664.418762
      L2CAP: Disconnection Response (0x07) ident 17 len 4
        Destination CID: 65
        Source CID: 65
< ACL Data TX: Handle 43 flags 0x00 dlen 12           #22709 [hci0] 1664.421073
      L2CAP: Connection Request (0x02) ident 12 len 4
        PSM: 1 (0x0001)
        Source CID: 65
> ACL Data RX: Handle 43 flags 0x02 dlen 12           #22710 [hci0] 1664.421371
      L2CAP: Disconnection Response (0x07) ident 11 len 4
        Destination CID: 65
        Source CID: 65
> HCI Event: Number of Completed Pac.. (0x13) plen 5  #22711 [hci0] 1664.424082
        Num handles: 1
        Handle: 43
        Count: 1
> HCI Event: Number of Completed Pac.. (0x13) plen 5  #22712 [hci0] 1664.425040
        Num handles: 1
        Handle: 43
        Count: 1
> ACL Data RX: Handle 43 flags 0x02 dlen 12           #22713 [hci0] 1664.426103
      L2CAP: Connection Request (0x02) ident 18 len 4
        PSM: 3 (0x0003)
        Source CID: 65
< ACL Data TX: Handle 43 flags 0x00 dlen 16           #22714 [hci0] 1664.426186
      L2CAP: Connection Response (0x03) ident 18 len 8
        Destination CID: 66
        Source CID: 65
        Result: Connection successful (0x0000)
        Status: No further information available (0x0000)
< ACL Data TX: Handle 43 flags 0x00 dlen 27           #22715 [hci0] 1664.426196
      L2CAP: Configure Request (0x04) ident 13 len 19
        Destination CID: 65
        Flags: 0x0000
        Option: Maximum Transmission Unit (0x01) [mandatory]
          MTU: 1013
        Option: Retransmission and Flow Control (0x04) [mandatory]
          Mode: Basic (0x00)
          TX window size: 0
          Max transmit: 0
          Retransmission timeout: 0
          Monitor timeout: 0
          Maximum PDU size: 0
> ACL Data RX: Handle 43 flags 0x02 dlen 16           #22716 [hci0] 1664.428804
      L2CAP: Connection Response (0x03) ident 12 len 8
        Destination CID: 66
        Source CID: 65
        Result: Connection successful (0x0000)
        Status: No further information available (0x0000)
*snip*

Fix is to check that channel is in state BT_DISCONN before deleting the
channel.

This bug was found while fuzzing Bluez's OBEX implementation using
Synopsys Defensics.

Reported-by: Matti Kamunen <matti.kamunen@synopsys.com>
Reported-by: Ari Timonen <ari.timonen@synopsys.com>
Signed-off-by: Matias Karhumaa <matias.karhumaa@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/bluetooth/l2cap_core.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index 46afd560f242..c25f1e4846cd 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -4363,6 +4363,12 @@ static inline int l2cap_disconnect_rsp(struct l2cap_conn *conn,
 
 	l2cap_chan_lock(chan);
 
+	if (chan->state != BT_DISCONN) {
+		l2cap_chan_unlock(chan);
+		mutex_unlock(&conn->chan_lock);
+		return 0;
+	}
+
 	l2cap_chan_hold(chan);
 	l2cap_chan_del(chan, 0);
 
-- 
2.20.1

[PATCH AUTOSEL 4.4 53/53] Bluetooth: validate BLE connection interval updates

[Sasha Levin]

From: csonsino <csonsino@gmail.com>

[ Upstream commit c49a8682fc5d298d44e8d911f4fa14690ea9485e ]

Problem: The Linux Bluetooth stack yields complete control over the BLE
connection interval to the remote device.

The Linux Bluetooth stack provides access to the BLE connection interval
min and max values through /sys/kernel/debug/bluetooth/hci0/
conn_min_interval and /sys/kernel/debug/bluetooth/hci0/conn_max_interval.
These values are used for initial BLE connections, but the remote device
has the ability to request a connection parameter update. In the event
that the remote side requests to change the connection interval, the Linux
kernel currently only validates that the desired value is within the
acceptable range in the Bluetooth specification (6 - 3200, corresponding to
7.5ms - 4000ms). There is currently no validation that the desired value
requested by the remote device is within the min/max limits specified in
the conn_min_interval/conn_max_interval configurations. This essentially
leads to Linux yielding complete control over the connection interval to
the remote device.

The proposed patch adds a verification step to the connection parameter
update mechanism, ensuring that the desired value is within the min/max
bounds of the current connection. If the desired value is outside of the
current connection min/max values, then the connection parameter update
request is rejected and the negative response is returned to the remote
device. Recall that the initial connection is established using the local
conn_min_interval/conn_max_interval values, so this allows the Linux
administrator to retain control over the BLE connection interval.

The one downside that I see is that the current default Linux values for
conn_min_interval and conn_max_interval typically correspond to 30ms and
50ms respectively. If this change were accepted, then it is feasible that
some devices would no longer be able to negotiate to their desired
connection interval values. This might be remedied by setting the default
Linux conn_min_interval and conn_max_interval values to the widest
supported range (6 - 3200 / 7.5ms - 4000ms). This could lead to the same
behavior as the current implementation, where the remote device could
request to change the connection interval value to any value that is
permitted by the Bluetooth specification, and Linux would accept the
desired value.

Signed-off-by: Carey Sonsino <csonsino@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/bluetooth/hci_event.c  | 5 +++++
 net/bluetooth/l2cap_core.c | 9 ++++++++-
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index 37fe2b158c2a..c4e94f34d048 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -5062,6 +5062,11 @@ static void hci_le_remote_conn_param_req_evt(struct hci_dev *hdev,
 		return send_conn_param_neg_reply(hdev, handle,
 						 HCI_ERROR_UNKNOWN_CONN_ID);
 
+	if (min < hcon->le_conn_min_interval ||
+	    max > hcon->le_conn_max_interval)
+		return send_conn_param_neg_reply(hdev, handle,
+						 HCI_ERROR_INVALID_LL_PARAMS);
+
 	if (hci_check_conn_params(min, max, latency, timeout))
 		return send_conn_param_neg_reply(hdev, handle,
 						 HCI_ERROR_INVALID_LL_PARAMS);
diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index c25f1e4846cd..8cfba78d26f6 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -5266,7 +5266,14 @@ static inline int l2cap_conn_param_update_req(struct l2cap_conn *conn,
 
 	memset(&rsp, 0, sizeof(rsp));
 
-	err = hci_check_conn_params(min, max, latency, to_multiplier);
+	if (min < hcon->le_conn_min_interval ||
+	    max > hcon->le_conn_max_interval) {
+		BT_DBG("requested connection interval exceeds current bounds.");
+		err = -EINVAL;
+	} else {
+		err = hci_check_conn_params(min, max, latency, to_multiplier);
+	}
+
 	if (err)
 		rsp.result = cpu_to_le16(L2CAP_CONN_PARAM_REJECTED);
 	else
-- 
2.20.1