[LTP] [PATCH] accept02: Join the multicast group on lo

[Petr Vorel]

> Hi Anders, all,

> > The test joins the multicast group with interface 0. Then the kernel
> > needs a route to 224.0.0.0 to find a device. When we only have lo,
> > like in a QEMU guest with no network, there is no such route and the
> > test breaks:

> >   accept02.c:52: TBROK: setsockopt(3, 0, 42, ...) failed: ENODEV (19)

> > All traffic in the test goes over 127.0.0.1, so join the group on lo.

> > Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
> > ---
> >  testcases/kernel/syscalls/accept/accept02.c | 3 ++-
> >  1 file changed, 2 insertions(+), 1 deletion(-)

> > diff --git a/testcases/kernel/syscalls/accept/accept02.c b/testcases/kernel/syscalls/accept/accept02.c
> > index 17056625e933..09a1c35e2591 100644
> > --- a/testcases/kernel/syscalls/accept/accept02.c
> > +++ b/testcases/kernel/syscalls/accept/accept02.c
> > @@ -22,6 +22,7 @@
> >  #include <errno.h>
> >  #include <sys/socket.h>
> >  #include "tst_test.h"
> > +#include "tst_netdevice.h"
> >  #include "tst_safe_net.h"
> >  #include "tst_safe_pthread.h"

> > @@ -112,7 +113,7 @@ static void setup(void)
> >  	client_addr = tst_alloc(sizeof(*client_addr));
> >  	mc_group = tst_alloc(sizeof(*mc_group));

> > -	mc_group->gr_interface = 0;
> > +	mc_group->gr_interface = NETDEV_INDEX_BY_NAME("lo");

> Reviewed-by: Petr Vorel <pvorel@suse.cz>

> I tested that it really fixes the problem when no network and runs ok.
> But I'm not 100% sure that it did not affect the CVE reproducibility.
> Therefore I do not add my TBT.

And unfortunately this should be really verified if the change does not affect
reproducibility. Hopefully Martin will get time for that soon, but this will for
sure will not make it into the release planned for today.

Kind regards,
Petr

> Kind regards,
> Petr