[PATCH net] vsock: cope with memory allocation failure at socket creation time

[PATCH net] vsock: cope with memory allocation failure at socket creation time

[Paolo Abeni]

In the unlikely event that the kmalloc call in vmci_transport_socket_init()
fails, we end-up calling vmci_transport_destruct() with a NULL vmci_trans()
and oopsing.

This change addresses the above explicitly checking for zero vmci_trans()
at destruction time.

Reported-by: Xiumei Mu <xmu@redhat.com>
Fixes: d021c344051a ("VSOCK: Introduce VM Sockets")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
---
 net/vmw_vsock/vmci_transport.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/net/vmw_vsock/vmci_transport.c b/net/vmw_vsock/vmci_transport.c
index c361ce782412..c3d5ab01fba7 100644
--- a/net/vmw_vsock/vmci_transport.c
+++ b/net/vmw_vsock/vmci_transport.c
@@ -1651,6 +1651,10 @@ static void vmci_transport_cleanup(struct work_struct *work)
 
 static void vmci_transport_destruct(struct vsock_sock *vsk)
 {
+	/* transport can be NULL if we hit a failure at init() time */
+	if (!vmci_trans(vsk))
+		return;
+
 	/* Ensure that the detach callback doesn't use the sk/vsk
 	 * we are about to destruct.
 	 */
-- 
2.20.1

Re: [PATCH net] vsock: cope with memory allocation failure at socket creation time

[Stefano Garzarella]

On Thu, Feb 07, 2019 at 02:13:18PM +0100, Paolo Abeni wrote:
> In the unlikely event that the kmalloc call in vmci_transport_socket_init()
> fails, we end-up calling vmci_transport_destruct() with a NULL vmci_trans()
> and oopsing.
> 
> This change addresses the above explicitly checking for zero vmci_trans()
> at destruction time.
> 
> Reported-by: Xiumei Mu <xmu@redhat.com>
> Fixes: d021c344051a ("VSOCK: Introduce VM Sockets")
> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
> ---
>  net/vmw_vsock/vmci_transport.c | 4 ++++
>  1 file changed, 4 insertions(+)

Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>

Thanks,
Stefano

RE: [PATCH net] vsock: cope with memory allocation failure at socket creation time

[Jorgen S. Hansen]

> In the unlikely event that the kmalloc call in vmci_transport_socket_init()
> fails, we end-up calling vmci_transport_destruct() with a NULL vmci_trans()
> and oopsing.
> 
> This change addresses the above explicitly checking for zero vmci_trans() at
> destruction time.
> 
> Reported-by: Xiumei Mu <xmu@redhat.com>
> Fixes: d021c344051a ("VSOCK: Introduce VM Sockets")
> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
> ---
>  net/vmw_vsock/vmci_transport.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/net/vmw_vsock/vmci_transport.c
> b/net/vmw_vsock/vmci_transport.c index c361ce782412..c3d5ab01fba7
> 100644
> --- a/net/vmw_vsock/vmci_transport.c
> +++ b/net/vmw_vsock/vmci_transport.c
> @@ -1651,6 +1651,10 @@ static void vmci_transport_cleanup(struct
> work_struct *work)
> 
>  static void vmci_transport_destruct(struct vsock_sock *vsk)  {
> +	/* transport can be NULL if we hit a failure at init() time */
> +	if (!vmci_trans(vsk))
> +		return;
> +
>  	/* Ensure that the detach callback doesn't use the sk/vsk
>  	 * we are about to destruct.
>  	 */
> --
> 2.20.1

Reviewed-by: Jorgen Hansen <jhansen@vmware.com>

Thanks for fixing this,
Jorgen

Re: [PATCH net] vsock: cope with memory allocation failure at socket creation time

[David Miller]

From: Paolo Abeni <pabeni@redhat.com>
Date: Thu,  7 Feb 2019 14:13:18 +0100

> In the unlikely event that the kmalloc call in vmci_transport_socket_init()
> fails, we end-up calling vmci_transport_destruct() with a NULL vmci_trans()
> and oopsing.
> 
> This change addresses the above explicitly checking for zero vmci_trans()
> at destruction time.
> 
> Reported-by: Xiumei Mu <xmu@redhat.com>
> Fixes: d021c344051a ("VSOCK: Introduce VM Sockets")
> Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Applied and queued up for -stable, thanks.