examples/vhost: fix overflow in argument parsing

Change the way passing args to fix potential overflow in args process.

Coverity issue: 363741
Fixes: 965b06f03582 ("examples/vhost: enhance getopt_long usage")

Signed-off-by: Cheng Jiang <cheng1.jiang@intel.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>

diff --git a/examples/vhost/main.c b/examples/vhost/main.c
index ff48ba2..0bee1f3 100644 (file)
--- a/examples/vhost/main.c
+++ b/examples/vhost/main.c
@@ -55,9 +55,6 @@
 
 #define INVALID_PORT_ID 0xFF
 
-/* Maximum long option length for option parsing. */
-#define MAX_LONG_OPT_SZ 64
-
 /* mask of enabled ports */
 static uint32_t enabled_port_mask = 0;
 
@@ -97,7 +94,7 @@ static int builtin_net_driver;
 
 static int async_vhost_driver;
 
-static char dma_type[MAX_LONG_OPT_SZ];
+static char *dma_type;
 
 /* Specify timeout (in useconds) between retries on RX. */
 static uint32_t burst_rx_delay_time = BURST_RX_WAIT_US;
@@ -201,7 +198,7 @@ struct vhost_bufftable *vhost_txbuff[RTE_MAX_LCORE * MAX_VHOST_DEVICE];
 static inline int
 open_dma(const char *value)
 {
-       if (strncmp(dma_type, "ioat", 4) == 0)
+       if (dma_type != NULL && strncmp(dma_type, "ioat", 4) == 0)
                return open_ioat(value);
 
        return -1;
@@ -669,7 +666,7 @@ us_vhost_parse_args(int argc, char **argv)
                        break;
 
                case OPT_DMA_TYPE_NUM:
-                       strcpy(dma_type, optarg);
+                       dma_type = optarg;
                        break;
 
                case OPT_DMAS_NUM:
@@ -1472,7 +1469,7 @@ new_device(int vid)
                struct rte_vhost_async_features f;
                struct rte_vhost_async_channel_ops channel_ops;
 
-               if (strncmp(dma_type, "ioat", 4) == 0) {
+               if (dma_type != NULL && strncmp(dma_type, "ioat", 4) == 0) {
                        channel_ops.transfer_data = ioat_transfer_data_cb;
                        channel_ops.check_completed_copies =
                                ioat_check_completed_copies_cb;