[dpdk-stable] [PATCH v2] vhost: fix null pointer checking

[Tiwei Bie]

On Thu, Apr 04, 2019 at 09:53:17AM +0100, Mohammad Abdul Awal wrote:
> Null value for parameters will cause segfault.
> 
> Fixes: d7280c9fff ("vhost: support selective datapath")
> Fixes: 72e8543093df ("vhost: add API to get MTU value")
> Fixes: a277c71598 ("vhost: refactor code structure")
> Fixes: ca33faf9ef ("vhost: introduce API to fetch negotiated features")
> Fixes: eb32247457 ("vhost: export guest memory regions")
> Fixes: 40ef286f23 ("vhost: export vhost vring info")
> Fixes: bd2e0c3fe5 ("vhost: add APIs for live migration")
> Fixes: 0b8572a0c1 ("vhost: add external message handling to the API")
> Fixes: b4953225ce ("vhost: add APIs for datapath configuration")

Would be better to use the same length (12) for hashes.

> Cc: stable at dpdk.org
> 
> Signed-off-by: Mohammad Abdul Awal <mohammad.abdul.awal at intel.com>
> ---
>  lib/librte_vhost/socket.c |  2 +-
>  lib/librte_vhost/vdpa.c   |  5 ++++-
>  lib/librte_vhost/vhost.c  | 16 ++++++++--------
>  3 files changed, 13 insertions(+), 10 deletions(-)
> 
> diff --git a/lib/librte_vhost/socket.c b/lib/librte_vhost/socket.c
> index 3da9de62c..a89665946 100644
> --- a/lib/librte_vhost/socket.c
> +++ b/lib/librte_vhost/socket.c
> @@ -562,7 +562,7 @@ rte_vhost_driver_attach_vdpa_device(const char *path, int did)
>  {
>  	struct vhost_user_socket *vsocket;
>  
> -	if (rte_vdpa_get_device(did) == NULL)
> +	if (rte_vdpa_get_device(did) == NULL || path == NULL)

There are multiple APIs accepting `path` parameter without
validating it in socket.c. I meant we can do the check for
most of them in find_vhost_user_socket():

https://github.com/DPDK/dpdk/blob/bdcfcceb7a0b7534a0dba669279d18bd0f98d5e5/lib/librte_vhost/socket.c#L546

For the cases which can't be covered by the check in
find_vhost_user_socket(), we need to do the check separately,
e.g.:

https://github.com/DPDK/dpdk/blob/bdcfcceb7a0b7534a0dba669279d18bd0f98d5e5/lib/librte_vhost/socket.c#L972


For the rest,
Reviewed-by: Tiwei Bie <tiwei.bie at intel.com>

Thanks!
Tiwei