net/virtio-user: check value returned from malloc

Value returned from malloc is not checked for errors before being used.
This patch fixes following coverity issue.

    static struct vhost_memory_kernel *
    prepare_vhost_memory_kernel(void)
    {
        ...
        vm = malloc(sizeof(struct vhost_memory_kernel) +
                    max_regions *
                    sizeof(struct vhost_memory_region));
        ...
    >>>     CID 140744:    (NULL_RETURNS)
    >>>     Dereferencing a null pointer "vm".
                mr = &vm->regions[k++];

Coverity issue: 140744
Fixes: e3b434818bbb ("net/virtio-user: support kernel vhost")

Signed-off-by: Jianfeng Tan <jianfeng.tan@intel.com>
Acked-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>

diff --git a/drivers/net/virtio/virtio_user/vhost_kernel.c b/drivers/net/virtio/virtio_user/vhost_kernel.c
index 9b6637d..05aa6c6 100644 (file)
--- a/drivers/net/virtio/virtio_user/vhost_kernel.c
+++ b/drivers/net/virtio/virtio_user/vhost_kernel.c
@@ -114,6 +114,8 @@ prepare_vhost_memory_kernel(void)
        vm = malloc(sizeof(struct vhost_memory_kernel) +
                    max_regions *
                    sizeof(struct vhost_memory_region));
+       if (!vm)
+               return NULL;
 
        for (i = 0; i < RTE_MAX_MEMSEG; ++i) {
                seg = &rte_eal_get_configuration()->mem_config->memseg[i];