From: Stefano Garzarella <sgarzare@xxxxxxxxxx> commit 0bde59c1723a29e294765c96dbe5c7fb639c2f96 upstream. In vhost_vdpa_set_config_call() if eventfd_ctx_fdget() fails the 'v->config_ctx' contains an error instead of a valid pointer. Since we consider 'v->config_ctx' valid if it is not NULL, we should set it to NULL in this case to avoid to use an invalid pointer in other functions such as vhost_vdpa_config_put(). Fixes: 776f395004d8 ("vhost_vdpa: Support config interrupt in vdpa") Cc: lingshan.zhu@xxxxxxxxx Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Stefano Garzarella <sgarzare@xxxxxxxxxx> Link: https://lore.kernel.org/r/20210311135257.109460-3-sgarzare@xxxxxxxxxx Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx> Acked-by: Jason Wang <jasowang@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/vhost/vdpa.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) --- a/drivers/vhost/vdpa.c +++ b/drivers/vhost/vdpa.c @@ -335,8 +335,12 @@ static long vhost_vdpa_set_config_call(s if (!IS_ERR_OR_NULL(ctx)) eventfd_ctx_put(ctx); - if (IS_ERR(v->config_ctx)) - return PTR_ERR(v->config_ctx); + if (IS_ERR(v->config_ctx)) { + long ret = PTR_ERR(v->config_ctx); + + v->config_ctx = NULL; + return ret; + } v->vdpa->config->set_config_cb(v->vdpa, &cb);