2011-01-17 10:08:37

by Vasily Kulikov

Subject: [PATCH] net: bluetooth: fix locking problem

If alloc_skb() failed we still hold hci_dev_list_lock. The code should
unlock it before exit.

Signed-off-by: Vasiliy Kulikov <[email protected]>
---
Compile tested only.

net/bluetooth/mgmt.c | 4 +++-
1 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
index f827fd9..ace8726 100644
--- a/net/bluetooth/mgmt.c
+++ b/net/bluetooth/mgmt.c
@@ -111,8 +111,10 @@ static int read_index_list(struct sock *sk)

body_len = sizeof(*ev) + sizeof(*rp) + (2 * count);
skb = alloc_skb(sizeof(*hdr) + body_len, GFP_ATOMIC);
- if (!skb)
+ if (!skb) {
+ read_unlock(&hci_dev_list_lock);
return -ENOMEM;
+ }

hdr = (void *) skb_put(skb, sizeof(*hdr));
hdr->opcode = cpu_to_le16(MGMT_EV_CMD_COMPLETE);
--
1.7.0.4

2011-01-17 10:28:29

by Andrei Emeltchenko

Subject: Re: [PATCH] net: bluetooth: fix locking problem

On Mon, Jan 17, 2011 at 12:08 PM, Vasiliy Kulikov <[email protected]> wro=
te:
> If alloc_skb() failed we still hold hci_dev_list_lock. =A0The code should
> unlock it before exit.
>
> Signed-off-by: Vasiliy Kulikov <[email protected]>
> ---
> =A0Compile tested only.
>
> =A0net/bluetooth/mgmt.c | =A0 =A04 +++-
> =A01 files changed, 3 insertions(+), 1 deletions(-)
>
> diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
> index f827fd9..ace8726 100644
> --- a/net/bluetooth/mgmt.c
> +++ b/net/bluetooth/mgmt.c
> @@ -111,8 +111,10 @@ static int read_index_list(struct sock *sk)
>
> =A0 =A0 =A0 =A0body_len =3D sizeof(*ev) + sizeof(*rp) + (2 * count);
> =A0 =A0 =A0 =A0skb =3D alloc_skb(sizeof(*hdr) + body_len, GFP_ATOMIC);
> - =A0 =A0 =A0 if (!skb)
> + =A0 =A0 =A0 if (!skb) {
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 read_unlock(&hci_dev_list_lock);
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0return -ENOMEM;
> + =A0 =A0 =A0 }

patch was send already on weekend

>
> =A0 =A0 =A0 =A0hdr =3D (void *) skb_put(skb, sizeof(*hdr));
> =A0 =A0 =A0 =A0hdr->opcode =3D cpu_to_le16(MGMT_EV_CMD_COMPLETE);
> --
> 1.7.0.4
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" i=
n
> the body of a message to [email protected]
> More majordomo info at =A0http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at =A0http://www.tux.org/lkml/
>