Hi,
> -----Original Message-----
> From: David Marchand <david.march...@redhat.com>
> Sent: Monday, April 26, 2021 4:25 PM
> To: Jiang, Cheng1 <cheng1.ji...@intel.com>
> Cc: Maxime Coquelin <maxime.coque...@redhat.com>; Xia, Chenbo
> <chenbo....@intel.com>; dev <dev@dpdk.org>; dpdk stable
> <sta...@dpdk.org>
> Subject: Re: [dpdk-stable] [PATCH] examples/vhost: fix potential overflow in
> args process
>
> On Mon, Apr 19, 2021 at 7:59 AM Cheng Jiang <cheng1.ji...@intel.com>
> wrote:
> >
> > Add args length check to fix potential overflow issue.
> >
> > Coverity issue: 363741
> > Fixes: 965b06f0358 ("examples/vhost: enhance getopt_long usage")
> > Cc: sta...@dpdk.org
>
> No need for Cc: stable since this issue only affects the current release.
Sure, sorry about that.
>
> >
> > Signed-off-by: Cheng Jiang <cheng1.ji...@intel.com>
>
> It should indeed fix the coverity report but this limit does not make sense.
> Could you make dma_type point at either optarg (it should be fine as
> we only read this string)?
>
> Something like (untested):
>
> diff --git a/examples/vhost/main.c b/examples/vhost/main.c
> index 2ca7d98c58..158e5e9a8a 100644
> --- 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;
>
>
>
> --
> David Marchand
I think that make sense. I'll send a new version according your comments.
Thanks.
Cheng
