2016-01-21 04:45:58

by Fugang Duan

[permalink] [raw]
Subject: [PATCH] Bluetooth: add hdev check to avoid passing null pointer

Function hci_mgmt_cmd() may pass hdev with null pointer to hci_mgmt_handler->func()
like below code:
err = handler->func(sk, hdev, cp, len);

Add hdev check to avoid passing null pointer.

Signed-off-by: Fugang Duan <[email protected]>
---
net/bluetooth/hci_sock.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/net/bluetooth/hci_sock.c b/net/bluetooth/hci_sock.c
index 1298d72..7fdfc80 100644
--- a/net/bluetooth/hci_sock.c
+++ b/net/bluetooth/hci_sock.c
@@ -1186,6 +1186,8 @@ static int hci_mgmt_cmd(struct hci_mgmt_chan *chan, struct sock *sk,

if (hdev && chan->hdev_init)
chan->hdev_init(sk, hdev);
+ else if (!hdev)
+ goto done;

cp = buf + sizeof(*hdr);

--
1.9.1


2016-01-21 09:23:30

by Andy Duan

[permalink] [raw]
Subject: RE: [PATCH] Bluetooth: add hdev check to avoid passing null pointer

From: Johan Hedberg <[email protected]> Sent: Tuesday, January 19, 20=
16 9:04 PM
> To: [email protected]
> Cc: [email protected]; [email protected]; linux-
> [email protected]
> Subject: Re: [PATCH] Bluetooth: add hdev check to avoid passing null poin=
ter
>=20
> Hi Fuang,
>=20
> On Tue, Jan 19, 2016, Fugang Duan wrote:
> > Function hci_mgmt_cmd() may pass hdev with null pointer to
> > hci_mgmt_handler->func() like below code:
> > err =3D handler->func(sk, hdev, cp, len);
> >
> > Add hdev check to avoid passing null pointer.
> >
> > Signed-off-by: Fugang Duan <[email protected]>
> > ---
> > net/bluetooth/hci_sock.c | 2 ++
> > 1 file changed, 2 insertions(+)
> >
> > diff --git a/net/bluetooth/hci_sock.c b/net/bluetooth/hci_sock.c index
> > 1298d72..7fdfc80 100644
> > --- a/net/bluetooth/hci_sock.c
> > +++ b/net/bluetooth/hci_sock.c
> > @@ -1186,6 +1186,8 @@ static int hci_mgmt_cmd(struct hci_mgmt_chan
> > *chan, struct sock *sk,
> >
> > if (hdev && chan->hdev_init)
> > chan->hdev_init(sk, hdev);
> > + else if (!hdev)
> > + goto done;
> >
> > cp =3D buf + sizeof(*hdr);
>=20
> Nack. There are handlers which are not hci-dev specific, such as reading =
version
> number, supported commands, or the index list. There's a special flag
> HCI_MGMT_NO_HDEV that handlers can set to say that they expect to be
> called without a hdev. The code in hci_mgmt_cmd() already makes sure that
> any handler that doesn't set it will not be called with NULL hdev.
>=20
> Johan

Thanks for your comments, the below piece of code can guarantee that any ha=
ndler doesn't set HCI_MGMT_NO_HDEV will not be called with NULL hdev.

no_hdev =3D (handler->flags & HCI_MGMT_NO_HDEV);
if (no_hdev !=3D !hdev) {
err =3D mgmt_cmd_status(sk, index, opcode,
MGMT_STATUS_INVALID_INDEX);
goto done;
}

Regards,
Andy

2016-01-21 09:06:08

by Andy Duan

[permalink] [raw]
Subject: RE: [PATCH] Bluetooth: add hdev check to avoid passing null pointer

From: Johan Hedberg <[email protected]> Sent: Thursday, January 21, 2=
016 4:43 PM
> To: [email protected]
> Cc: [email protected]; [email protected]; [email protected]; linux-
> [email protected]; Fugang Duan <[email protected]>
> Subject: Re: [PATCH] Bluetooth: add hdev check to avoid passing null poin=
ter
>=20
> Hi Fuang,
>=20
> On Thu, Jan 21, 2016, Fugang Duan wrote:
> > Function hci_mgmt_cmd() may pass hdev with null pointer to
> > hci_mgmt_handler->func() like below code:
> > err =3D handler->func(sk, hdev, cp, len);
> >
> > Add hdev check to avoid passing null pointer.
> >
> > Signed-off-by: Fugang Duan <[email protected]>
> > ---
> > net/bluetooth/hci_sock.c | 2 ++
> > 1 file changed, 2 insertions(+)
> >
> > diff --git a/net/bluetooth/hci_sock.c b/net/bluetooth/hci_sock.c index
> > 1298d72..7fdfc80 100644
> > --- a/net/bluetooth/hci_sock.c
> > +++ b/net/bluetooth/hci_sock.c
> > @@ -1186,6 +1186,8 @@ static int hci_mgmt_cmd(struct hci_mgmt_chan
> > *chan, struct sock *sk,
> >
> > if (hdev && chan->hdev_init)
> > chan->hdev_init(sk, hdev);
> > + else if (!hdev)
> > + goto done;
>=20
> Why are you resending this? Did you see my response to your earlier
> submission?
>=20
> Johan

Sorry, maybe I missed some mail and guessed I didn't send the previous mai=
l successfully. =20
Let's check my mailbox=20

Regards,
Andy

2016-01-21 08:43:10

by Johan Hedberg

[permalink] [raw]
Subject: Re: [PATCH] Bluetooth: add hdev check to avoid passing null pointer

Hi Fuang,

On Thu, Jan 21, 2016, Fugang Duan wrote:
> Function hci_mgmt_cmd() may pass hdev with null pointer to hci_mgmt_handler->func()
> like below code:
> err = handler->func(sk, hdev, cp, len);
>
> Add hdev check to avoid passing null pointer.
>
> Signed-off-by: Fugang Duan <[email protected]>
> ---
> net/bluetooth/hci_sock.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/net/bluetooth/hci_sock.c b/net/bluetooth/hci_sock.c
> index 1298d72..7fdfc80 100644
> --- a/net/bluetooth/hci_sock.c
> +++ b/net/bluetooth/hci_sock.c
> @@ -1186,6 +1186,8 @@ static int hci_mgmt_cmd(struct hci_mgmt_chan *chan, struct sock *sk,
>
> if (hdev && chan->hdev_init)
> chan->hdev_init(sk, hdev);
> + else if (!hdev)
> + goto done;

Why are you resending this? Did you see my response to your earlier
submission?

Johan

2016-01-19 13:04:04

by Johan Hedberg

[permalink] [raw]
Subject: Re: [PATCH] Bluetooth: add hdev check to avoid passing null pointer

Hi Fuang,

On Tue, Jan 19, 2016, Fugang Duan wrote:
> Function hci_mgmt_cmd() may pass hdev with null pointer to hci_mgmt_handler->func()
> like below code:
> err = handler->func(sk, hdev, cp, len);
>
> Add hdev check to avoid passing null pointer.
>
> Signed-off-by: Fugang Duan <[email protected]>
> ---
> net/bluetooth/hci_sock.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/net/bluetooth/hci_sock.c b/net/bluetooth/hci_sock.c
> index 1298d72..7fdfc80 100644
> --- a/net/bluetooth/hci_sock.c
> +++ b/net/bluetooth/hci_sock.c
> @@ -1186,6 +1186,8 @@ static int hci_mgmt_cmd(struct hci_mgmt_chan *chan, struct sock *sk,
>
> if (hdev && chan->hdev_init)
> chan->hdev_init(sk, hdev);
> + else if (!hdev)
> + goto done;
>
> cp = buf + sizeof(*hdr);

Nack. There are handlers which are not hci-dev specific, such as reading
version number, supported commands, or the index list. There's a special
flag HCI_MGMT_NO_HDEV that handlers can set to say that they expect to
be called without a hdev. The code in hci_mgmt_cmd() already makes sure
that any handler that doesn't set it will not be called with NULL hdev.

Johan