Return-Path: Subject: Re: [PATCH 2/5] Bluetooth: Validate PSM values in calls to connect() and bind(). From: Marcel Holtmann To: Mat Martineau Cc: linux-bluetooth@vger.kernel.org, gustavo@padovan.org, rshaffer@codeaurora.org, linux-arm-msm@vger.kernel.org In-Reply-To: <1281466850-5297-3-git-send-email-mathewm@codeaurora.org> References: <1281466850-5297-1-git-send-email-mathewm@codeaurora.org> <1281466850-5297-3-git-send-email-mathewm@codeaurora.org> Content-Type: text/plain; charset="UTF-8" Date: Tue, 10 Aug 2010 17:21:10 -0400 Message-ID: <1281475270.12579.223.camel@localhost.localdomain> Mime-Version: 1.0 Sender: linux-bluetooth-owner@vger.kernel.org List-ID: Hi Mat, > Valid L2CAP PSMs are odd numbers, and the least significant bit of the > most significant byte must be 0. > > Signed-off-by: Mat Martineau > --- > net/bluetooth/l2cap.c | 23 +++++++++++++++++++---- > 1 files changed, 19 insertions(+), 4 deletions(-) > > diff --git a/net/bluetooth/l2cap.c b/net/bluetooth/l2cap.c > index c784703..61aa961 100644 > --- a/net/bluetooth/l2cap.c > +++ b/net/bluetooth/l2cap.c > @@ -1008,10 +1008,19 @@ static int l2cap_sock_bind(struct socket *sock, struct sockaddr *addr, int alen) > goto done; > } > > - if (la.l2_psm && __le16_to_cpu(la.l2_psm) < 0x1001 && > - !capable(CAP_NET_BIND_SERVICE)) { > - err = -EACCES; > - goto done; > + /* If specified, PSM must be odd and lsb of upper byte must be 0 */ > + if (la.l2_psm) { > + __u16 psm = __le16_to_cpu(la.l2_psm); > + I would just put the comment here: /* PSM must be odd and lsb of upper byte must be 0 */ > + if ((psm & 0x0101) != 0x0001) { > + err = -EINVAL; > + goto done; > + } And then while you at it: /* Restrict usage of well known PSMs */ > + if (psm < 0x1001 && !capable(CAP_NET_BIND_SERVICE)) { > + err = -EACCES; > + goto done; > + } > } Maybe there is actually a second place for adding that comment. Otherwise I am fine with this, but since it is not a regression, this will be only taking in the next tree. Regards Marcel