Return-Path: Date: Tue, 20 Dec 2011 17:05:04 -0200 From: Gustavo Padovan To: Emeltchenko Andrei Cc: linux-bluetooth@vger.kernel.org Subject: Re: [PATCHv3 5/5] Bluetooth: Correct packet len calculation Message-ID: <20111220190504.GA24612@joana> References: <1324305091-19393-1-git-send-email-Andrei.Emeltchenko.news@gmail.com> <1324305091-19393-6-git-send-email-Andrei.Emeltchenko.news@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1324305091-19393-6-git-send-email-Andrei.Emeltchenko.news@gmail.com> Sender: linux-bluetooth-owner@vger.kernel.org List-ID: Hi Andrei, * Emeltchenko Andrei [2011-12-19 16:31:31 +0200]: > From: Andrei Emeltchenko > > 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 > --- > 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)) { I think you can remove the first part of this check. Gustavo