From: Bruce Richardson <bruce.richardson@intel.com>
To: "Wiles, Keith" <keith.wiles@intel.com>
Cc: "dev@dpdk.org" <dev@dpdk.org>
Subject: Re: [dpdk-dev] [PATCH] net/tap: fix coverity warning on strncpy
Date: Fri, 17 Feb 2017 15:13:26 +0000 [thread overview]
Message-ID: <20170217151325.GA116880@bricha3-MOBL3.ger.corp.intel.com> (raw)
In-Reply-To: <D8053801-BD60-46B3-9BF2-417044D78ACD@intel.com>
On Fri, Feb 17, 2017 at 03:05:40PM +0000, Wiles, Keith wrote:
>
> > On Feb 17, 2017, at 9:02 AM, Richardson, Bruce <bruce.richardson@intel.com> wrote:
> >
> > On Fri, Feb 17, 2017 at 08:44:26AM -0600, Keith Wiles wrote:
> >> Calling strncpy with a maximum size argument of 16 bytes on destination
> >> array "ifr.ifr_ifrn.ifrn_name" of size 16 bytes might leave the
> >> destination string unterminated.
> >>
> >> Signed-off-by: Keith Wiles <keith.wiles@intel.com>
> >> ---
> >> drivers/net/tap/rte_eth_tap.c | 2 +-
> >> 1 file changed, 1 insertion(+), 1 deletion(-)
> >>
> >> diff --git a/drivers/net/tap/rte_eth_tap.c b/drivers/net/tap/rte_eth_tap.c
> >> index efc4426..f9938d7 100644
> >> --- a/drivers/net/tap/rte_eth_tap.c
> >> +++ b/drivers/net/tap/rte_eth_tap.c
> >> @@ -297,7 +297,7 @@ tap_link_set_flags(struct pmd_internals *pmd, short flags, int add)
> >> return -1;
> >> }
> >> memset(&ifr, 0, sizeof(ifr));
> >> - strncpy(ifr.ifr_name, pmd->name, IFNAMSIZ);
> >> + strncpy(ifr.ifr_name, pmd->name, IFNAMSIZ-1);
> > This is why I always prefer to use snprintf for copying strings, you
> > can't avoid null terminating.
>
> Normally I use snprintf to not sure why I reverted to strncpy. Maybe leftover from a previous driver I used as the template.
>
Is there a case to be made that DPDK should provide a strlcpy function
in the linuxapp EAL? [Assuming we don't want a dependency on libbsd?]
I find strncpy a horribly-error prone function to use - worse than
strcpy, since it gives a false sense of safety.
/Bruce
next prev parent reply other threads:[~2017-02-17 15:13 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-02-17 14:44 Keith Wiles
2017-02-17 14:48 ` Wiles, Keith
2017-02-17 15:02 ` Bruce Richardson
2017-02-17 15:05 ` Wiles, Keith
2017-02-17 15:13 ` Bruce Richardson [this message]
2017-02-17 15:15 ` Ferruh Yigit
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