net/bluetooth/a2mp.c:205 a2mp_getinfo_req() error: we previously assumed

Hi Andrei,

FYI, there are new smatch warnings show up in

tree:   git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth-next.git master
head:   29d8a5909bba10accb82eb805c884a2943d7710f
commit: 8e2a0d92c56ec6955526a8b60838c9b00f70540d [222/247] Bluetooth: AMP: Use HCI cmd to Read AMP Info

net/bluetooth/a2mp.c:61 a2mp_send() Error invalid range 4096 to -1
+ net/bluetooth/a2mp.c:205 a2mp_getinfo_req() error: we previously assumed 'hdev' could be null (see line 195)

vim +205 net/bluetooth/a2mp.c

47f2d97d (Andrei Emeltchenko 2012-05-29  189) 	if (le16_to_cpu(hdr->len) < sizeof(*req))
47f2d97d (Andrei Emeltchenko 2012-05-29  190) 		return -EINVAL;
47f2d97d (Andrei Emeltchenko 2012-05-29  191) 
47f2d97d (Andrei Emeltchenko 2012-05-29  192) 	BT_DBG("id %d", req->id);
47f2d97d (Andrei Emeltchenko 2012-05-29  193) 
47f2d97d (Andrei Emeltchenko 2012-05-29  194) 	hdev = hci_dev_get(req->id);
8e2a0d92 (Andrei Emeltchenko 2012-09-27 @195) 	if (!hdev) {
8e2a0d92 (Andrei Emeltchenko 2012-09-27  196) 		struct a2mp_info_rsp rsp;
8e2a0d92 (Andrei Emeltchenko 2012-09-27  197) 
8e2a0d92 (Andrei Emeltchenko 2012-09-27  198) 		rsp.id = req->id;
8e2a0d92 (Andrei Emeltchenko 2012-09-27  199) 		rsp.status = A2MP_STATUS_INVALID_CTRL_ID;
8e2a0d92 (Andrei Emeltchenko 2012-09-27  200) 
8e2a0d92 (Andrei Emeltchenko 2012-09-27  201) 		a2mp_send(mgr, A2MP_GETINFO_RSP, hdr->ident, sizeof(rsp),
8e2a0d92 (Andrei Emeltchenko 2012-09-27  202) 			  &rsp);
47f2d97d (Andrei Emeltchenko 2012-05-29  203) 	}
47f2d97d (Andrei Emeltchenko 2012-05-29  204) 
8e2a0d92 (Andrei Emeltchenko 2012-09-27 @205) 	if (hdev->dev_type != HCI_BREDR) {
8e2a0d92 (Andrei Emeltchenko 2012-09-27  206) 		mgr->state = READ_LOC_AMP_INFO;
8e2a0d92 (Andrei Emeltchenko 2012-09-27  207) 		hci_send_cmd(hdev, HCI_OP_READ_LOCAL_AMP_INFO, 0, NULL);
8e2a0d92 (Andrei Emeltchenko 2012-09-27  208) 	}
47f2d97d (Andrei Emeltchenko 2012-05-29  209) 
8e2a0d92 (Andrei Emeltchenko 2012-09-27  210) 	hci_dev_put(hdev);
47f2d97d (Andrei Emeltchenko 2012-05-29  211) 
47f2d97d (Andrei Emeltchenko 2012-05-29  212) 	skb_pull(skb, sizeof(*req));
47f2d97d (Andrei Emeltchenko 2012-05-29  213) 	return 0;

---
0-DAY kernel build testing backend Open Source Technology Centre
Fengguang Wu, Yuanhan Liu Intel Corporation

From: Andrei Emeltchenko <[email protected]>

Return INVALID_CTRL_ID for unknown AMP controller and for BR/EDR controller and fixes dereference possible NULL pointer.

---
 net/bluetooth/a2mp.c |   14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

index 61e657a..a55449e 100644
@@ -278,7 +278,7 @@ static int a2mp_getinfo_req(struct amp_mgr *mgr, struct sk_buff *skb,
 	BT_DBG("id %d", req->id);
 
 	hdev = hci_dev_get(req->id);
-	if (!hdev) {
+	if (!hdev || hdev->dev_type != HCI_AMP) {
 		struct a2mp_info_rsp rsp;
 
 		rsp.id = req->id;

@@ -286,14 +286,16 @@ static int a2mp_getinfo_req(struct amp_mgr *mgr, struct sk_buff *skb,
 
 		a2mp_send(mgr, A2MP_GETINFO_RSP, hdr->ident, sizeof(rsp),
 			  &rsp);
-	}
 
-	if (hdev->dev_type != HCI_BREDR) {
-		mgr->state = READ_LOC_AMP_INFO;
-		hci_send_cmd(hdev, HCI_OP_READ_LOCAL_AMP_INFO, 0, NULL);
+		goto done;
 	}
 
-	hci_dev_put(hdev);
+	mgr->state = READ_LOC_AMP_INFO;
+	hci_send_cmd(hdev, HCI_OP_READ_LOCAL_AMP_INFO, 0, NULL);
+
+done:
+	if (hdev)
+		hci_dev_put(hdev);
 
 	skb_pull(skb, sizeof(*req));
 	return 0;

1.7.9.5

Hi Andrei,

Patch has been applied to bluetooth-next, Thanks.

Gustavo