On Fri, Jan 29, 2016 at 11:37 AM, Cong Wang <[email protected]> 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.
>
> Just lock the sock since this is not a hot path anyway.
>
> Reported-by: Dmitry Vyukov <[email protected]>
> Cc: Lauro Ramos Venancio <[email protected]>
> Cc: Aloisio Almeida Jr <[email protected]>
> Cc: Samuel Ortiz <[email protected]>
> Signed-off-by: Cong Wang <[email protected]>
Samuel, please take a look at this one too.
> ---
> net/nfc/llcp_sock.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/net/nfc/llcp_sock.c b/net/nfc/llcp_sock.c
> index ecf0a01..b9edf5f 100644
> --- a/net/nfc/llcp_sock.c
> +++ b/net/nfc/llcp_sock.c
> @@ -509,6 +509,11 @@ static int llcp_sock_getname(struct socket *sock, struct
> sockaddr *uaddr,
> memset(llcp_addr, 0, sizeof(*llcp_addr));
> *len = sizeof(struct sockaddr_nfc_llcp);
>
> + lock_sock(sk);
> + if (!llcp_sock->dev) {
> + release_sock(sk);
> + return -EBADFD;
> + }
> llcp_addr->sa_family = AF_NFC;
> llcp_addr->dev_idx = llcp_sock->dev->idx;
> llcp_addr->target_idx = llcp_sock->target_idx;
> @@ -518,6 +523,7 @@ static int llcp_sock_getname(struct socket *sock, struct
> sockaddr *uaddr,
> llcp_addr->service_name_len = llcp_sock->service_name_len;
> memcpy(llcp_addr->service_name, llcp_sock->service_name,
> llcp_addr->service_name_len);
> + release_sock(sk);
>
> return 0;
> }
> --
> 1.8.3.1
>
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