Re: [dpdk-dev] [PATCH 1/2] timer: fix null pointer dereference

["Carrillo, Erik G" <erik.g.carrillo@intel.com>]

> -----Original Message-----
> From: Carrillo, Erik G
> Sent: Monday, July 15, 2019 11:04 AM
> To: Stephen Hemminger <stephen@networkplumber.org>
> Cc: thomas@monjalon.net; dev@dpdk.org; stable@dpdk.org
> Subject: RE: [dpdk-dev] [PATCH 1/2] timer: fix null pointer dereference
> 
> Hi Stephen,
> 
> > -----Original Message-----
> > From: Stephen Hemminger <stephen@networkplumber.org>
> > Sent: Monday, July 15, 2019 10:49 AM
> > To: Carrillo, Erik G <erik.g.carrillo@intel.com>
> > Cc: thomas@monjalon.net; dev@dpdk.org; stable@dpdk.org
> > Subject: Re: [dpdk-dev] [PATCH 1/2] timer: fix null pointer
> > dereference
> >
> > On Mon, 15 Jul 2019 10:39:31 -0500
> > Erik Gabriel Carrillo <erik.g.carrillo@intel.com> wrote:
> >
> > > If the timer subsystem is not initialized before rte_timer_manage
> > > (for
> > > example) is invoked, a pointer to a shared hugepage memory region
> > > will still be null and dereferenced when it is checked for validity;
> > > handle this case.
> > >
> > > Fixes: c0749f7096c7 ("timer: allow management in shared memory")
> > > Cc: stable@dpdk.org
> > >
> > > Signed-off-by: Erik Gabriel Carrillo <erik.g.carrillo@intel.com>
> >
> > I have mixed feelings about this patch.
> > Any calls to rte_timer before rte_timer_subsystem_init is not a valid usage.
> > Better to kill the application.
> 
> Ok, that sounds like a better approach.  I'll update the patch and resubmit.
> 

I added a call to rte_exit() in the timer_data_valid() function for the case where the library is uninitialized, but checkpatches.sh issues the following warning:

"Warning in /lib/librte_timer/rte_timer.c:
Using rte_panic/rte_exit"

According to the comments in the script, we should refrain from new additions of rte_panic() and rte_exit() in the lib subtree.   In light of this, should we still proceed with this approach?  It does seem like it would be useful.

Thanks,
Erik

> Thanks,
> Erik