[PATCH] Bluetooth: Correct packet len calculation

[PATCH] Bluetooth: Correct packet len calculation

[Emeltchenko Andrei]

From: Andrei Emeltchenko <andrei.emeltchenko@intel.com>

Remove unneeded skb_pull and correct packet length calculation
removing magic number. Move BT_DBG after len check otherwise
it could possibly access wrong memory.

Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
---
 net/bluetooth/hci_event.c |    9 ++++-----
 1 files changed, 4 insertions(+), 5 deletions(-)

diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index 919e3c0..47e1476 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -2266,20 +2266,19 @@ static inline void hci_num_comp_pkts_evt(struct hci_dev *hdev, struct sk_buff *s
 	struct hci_ev_num_comp_pkts *ev = (void *) skb->data;
 	int i;
 
-	skb_pull(skb, sizeof(*ev));
-
-	BT_DBG("%s num_hndl %d", hdev->name, ev->num_hndl);
-
 	if (hdev->flow_ctl_mode != HCI_FLOW_CTL_MODE_PACKET_BASED) {
 		BT_ERR("Wrong event for mode %d", hdev->flow_ctl_mode);
 		return;
 	}
 
-	if (skb->len < ev->num_hndl * 4) {
+	if (skb->len < sizeof(*ev) || skb->len < sizeof(*ev) +
+			ev->num_hndl * sizeof(struct hci_comp_pkts_info)) {
 		BT_DBG("%s bad parameters", hdev->name);
 		return;
 	}
 
+	BT_DBG("%s num_hndl %d", hdev->name, ev->num_hndl);
+
 	for (i = 0; i < ev->num_hndl; i++) {
 		struct hci_comp_pkts_info *info = &ev->handles[i];
 		struct hci_conn *conn;
-- 
1.7.4.1

Re: [PATCH] Bluetooth: Correct packet len calculation

[Gustavo Padovan]

Hi Andrei,

* Emeltchenko Andrei <Andrei.Emeltchenko.news@gmail.com> [2011-12-30 12:07:47 +0200]:

> From: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
> 
> Remove unneeded skb_pull and correct packet length calculation
> removing magic number. Move BT_DBG after len check otherwise
> it could possibly access wrong memory.
> 
> Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
> Acked-by: Marcel Holtmann <marcel@holtmann.org>
> ---
>  net/bluetooth/hci_event.c |    9 ++++-----
>  1 files changed, 4 insertions(+), 5 deletions(-)

Applied, thanks.

	Gustavo