Return-Path: Date: Thu, 19 Mar 2015 10:25:39 +0200 From: Johan Hedberg To: Harish Jenny K N Cc: linux-bluetooth@vger.kernel.org Subject: Re: [PATCH] Bluetooth: Fix use after free in l2cap_chan_timeout Message-ID: <20150319082539.GA29243@t440s.lan> References: <1426753191-9468-1-git-send-email-harish_kandiga@mentor.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1426753191-9468-1-git-send-email-harish_kandiga@mentor.com> Sender: linux-bluetooth-owner@vger.kernel.org List-ID: Hi, On Thu, Mar 19, 2015, Harish Jenny K N wrote: > There is a potential use after free in bt_sock_poll when a > socket gets killed without getting unlinked from accept_q. > Hence added code to unlink from accpept_q by calling teardown > before freeing the socket for channel type L2CAP_CHAN_CONN_ORIENTED. > > Signed-off-by: Harish Jenny K N > --- > net/bluetooth/l2cap_core.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c > index 6ba33f9..c6955fb 100644 > --- a/net/bluetooth/l2cap_core.c > +++ b/net/bluetooth/l2cap_core.c > @@ -415,6 +415,11 @@ static void l2cap_chan_timeout(struct work_struct *work) > > l2cap_chan_close(chan, reason); > > + if ((chan->state == BT_CONNECTED || chan->state == BT_CONFIG) && > + chan->chan_type == L2CAP_CHAN_CONN_ORIENTED) { > + chan->ops->teardown(chan, 0); > + } Looks quite ok to me, except for a minor issue: we generally don't use {} for single-line branches. Do you have some simple way to reproduce this? It'd be nice if we could add a test case for it to our user space l2cap-tester tool. Johan