* [Patch net] nfc: use GFP_USER for user-controlled kmalloc
@ 2016-01-02 0:34 Cong Wang
2016-01-02 0:34 ` [Patch net] nfc: check sock state in llcp_sock_getname() Cong Wang
0 siblings, 1 reply; 4+ messages in thread
From: Cong Wang @ 2016-01-02 0:34 UTC (permalink / raw)
To: netdev-u79uwXL29TY76Z2rM5mHXA
Cc: dvyukov-hpIqsD4AKlfQT0dZR+AlfA,
linux-wireless-u79uwXL29TY76Z2rM5mHXA, Cong Wang,
Lauro Ramos Venancio, Aloisio Almeida Jr, Samuel Ortiz
Reported-by: Dmitry Vyukov <dvyukov-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
Cc: Lauro Ramos Venancio <lauro.venancio-430g2QfJUUCGglJvpFV4uA@public.gmane.org>
Cc: Aloisio Almeida Jr <aloisio.almeida-430g2QfJUUCGglJvpFV4uA@public.gmane.org>
Cc: Samuel Ortiz <sameo-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
Signed-off-by: Cong Wang <xiyou.wangcong-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
---
net/nfc/llcp_commands.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/nfc/llcp_commands.c b/net/nfc/llcp_commands.c
index 3621a90..5d94055 100644
--- a/net/nfc/llcp_commands.c
+++ b/net/nfc/llcp_commands.c
@@ -729,7 +729,7 @@ int nfc_llcp_send_ui_frame(struct nfc_llcp_sock *sock, u8 ssap, u8 dsap,
if (local == NULL)
return -ENODEV;
- msg_data = kzalloc(len, GFP_KERNEL);
+ msg_data = kzalloc(len, GFP_USER | __GFP_NOWARN);
if (msg_data == NULL)
return -ENOMEM;
--
1.8.3.1
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^ permalink raw reply related [flat|nested] 4+ messages in thread
* [Patch net] nfc: check sock state in llcp_sock_getname()
2016-01-02 0:34 [Patch net] nfc: use GFP_USER for user-controlled kmalloc Cong Wang
@ 2016-01-02 0:34 ` Cong Wang
[not found] ` <1451694857-21873-2-git-send-email-xiyou.wangcong-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
0 siblings, 1 reply; 4+ messages in thread
From: Cong Wang @ 2016-01-02 0:34 UTC (permalink / raw)
To: netdev
Cc: dvyukov, linux-wireless, Cong Wang, Lauro Ramos Venancio,
Aloisio Almeida Jr, Samuel Ortiz
llcp_sock_getname() checks llcp_sock->dev to make sure
llcp_sock is already connected or bound, however, we could
be in the middle of llcp_sock_bind() where llcp_sock->dev
is bound and llcp_sock->service_name_len is set,
but llcp_sock->service_name is not, in this case we would
lead to copy some bytes from a NULL pointer.
We should just check if sk->sk_state is still closed since
both connect() and bind() will update this state at the end.
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Lauro Ramos Venancio <lauro.venancio@openbossa.org>
Cc: Aloisio Almeida Jr <aloisio.almeida@openbossa.org>
Cc: Samuel Ortiz <sameo@linux.intel.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
---
net/nfc/llcp_sock.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/nfc/llcp_sock.c b/net/nfc/llcp_sock.c
index ecf0a01..5a91997 100644
--- a/net/nfc/llcp_sock.c
+++ b/net/nfc/llcp_sock.c
@@ -500,7 +500,7 @@ static int llcp_sock_getname(struct socket *sock, struct sockaddr *uaddr,
struct nfc_llcp_sock *llcp_sock = nfc_llcp_sock(sk);
DECLARE_SOCKADDR(struct sockaddr_nfc_llcp *, llcp_addr, uaddr);
- if (llcp_sock == NULL || llcp_sock->dev == NULL)
+ if (llcp_sock == NULL || sk->sk_state == LLCP_CLOSED)
return -EBADFD;
pr_debug("%p %d %d %d\n", sk, llcp_sock->target_idx,
--
1.8.3.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [Patch net] nfc: check sock state in llcp_sock_getname()
[not found] ` <1451694857-21873-2-git-send-email-xiyou.wangcong-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
@ 2016-01-02 8:03 ` Dmitry Vyukov
[not found] ` <CACT4Y+Y6YCYA_v=--spYpPDYj3Jo0cXcntFRe8XzYS3NJFUwqQ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
0 siblings, 1 reply; 4+ messages in thread
From: Dmitry Vyukov @ 2016-01-02 8:03 UTC (permalink / raw)
To: Cong Wang
Cc: netdev, linux-wireless-u79uwXL29TY76Z2rM5mHXA,
Lauro Ramos Venancio, Aloisio Almeida Jr, Samuel Ortiz
On Sat, Jan 2, 2016 at 1:34 AM, Cong Wang <xiyou.wangcong-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
> llcp_sock_getname() checks llcp_sock->dev to make sure
> llcp_sock is already connected or bound, however, we could
> be in the middle of llcp_sock_bind() where llcp_sock->dev
> is bound and llcp_sock->service_name_len is set,
> but llcp_sock->service_name is not, in this case we would
> lead to copy some bytes from a NULL pointer.
>
> We should just check if sk->sk_state is still closed since
> both connect() and bind() will update this state at the end.
Hi Cong,
This is still racy. If you want to play lock-free then you also need
proper memory barriers. Stores to sk_state need to be
smp_store_release, while the load needs to be smp_load_acquire.
Otherwise getname still can see partially initialized socket.
> Reported-by: Dmitry Vyukov <dvyukov-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
> Cc: Lauro Ramos Venancio <lauro.venancio-430g2QfJUUCGglJvpFV4uA@public.gmane.org>
> Cc: Aloisio Almeida Jr <aloisio.almeida-430g2QfJUUCGglJvpFV4uA@public.gmane.org>
> Cc: Samuel Ortiz <sameo-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
> Signed-off-by: Cong Wang <xiyou.wangcong-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> ---
> net/nfc/llcp_sock.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/net/nfc/llcp_sock.c b/net/nfc/llcp_sock.c
> index ecf0a01..5a91997 100644
> --- a/net/nfc/llcp_sock.c
> +++ b/net/nfc/llcp_sock.c
> @@ -500,7 +500,7 @@ static int llcp_sock_getname(struct socket *sock, struct sockaddr *uaddr,
> struct nfc_llcp_sock *llcp_sock = nfc_llcp_sock(sk);
> DECLARE_SOCKADDR(struct sockaddr_nfc_llcp *, llcp_addr, uaddr);
>
> - if (llcp_sock == NULL || llcp_sock->dev == NULL)
> + if (llcp_sock == NULL || sk->sk_state == LLCP_CLOSED)
> return -EBADFD;
>
> pr_debug("%p %d %d %d\n", sk, llcp_sock->target_idx,
> --
> 1.8.3.1
>
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^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [Patch net] nfc: check sock state in llcp_sock_getname()
[not found] ` <CACT4Y+Y6YCYA_v=--spYpPDYj3Jo0cXcntFRe8XzYS3NJFUwqQ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
@ 2016-01-03 22:36 ` Cong Wang
0 siblings, 0 replies; 4+ messages in thread
From: Cong Wang @ 2016-01-03 22:36 UTC (permalink / raw)
To: Dmitry Vyukov
Cc: netdev, linux-wireless-u79uwXL29TY76Z2rM5mHXA,
Lauro Ramos Venancio, Aloisio Almeida Jr, Samuel Ortiz
On Sat, Jan 2, 2016 at 12:03 AM, Dmitry Vyukov <dvyukov-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org> wrote:
> On Sat, Jan 2, 2016 at 1:34 AM, Cong Wang <xiyou.wangcong-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
>> llcp_sock_getname() checks llcp_sock->dev to make sure
>> llcp_sock is already connected or bound, however, we could
>> be in the middle of llcp_sock_bind() where llcp_sock->dev
>> is bound and llcp_sock->service_name_len is set,
>> but llcp_sock->service_name is not, in this case we would
>> lead to copy some bytes from a NULL pointer.
>>
>> We should just check if sk->sk_state is still closed since
>> both connect() and bind() will update this state at the end.
>
> Hi Cong,
>
> This is still racy. If you want to play lock-free then you also need
> proper memory barriers. Stores to sk_state need to be
> smp_store_release, while the load needs to be smp_load_acquire.
> Otherwise getname still can see partially initialized socket.
>
Right... Or just lock sock perhaps. I will update my patch.
Thanks!
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^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2016-01-03 22:36 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2016-01-02 0:34 [Patch net] nfc: use GFP_USER for user-controlled kmalloc Cong Wang
2016-01-02 0:34 ` [Patch net] nfc: check sock state in llcp_sock_getname() Cong Wang
[not found] ` <1451694857-21873-2-git-send-email-xiyou.wangcong-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2016-01-02 8:03 ` Dmitry Vyukov
[not found] ` <CACT4Y+Y6YCYA_v=--spYpPDYj3Jo0cXcntFRe8XzYS3NJFUwqQ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2016-01-03 22:36 ` Cong Wang
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