On Wed, May 06, 2020 at 12:06:10PM -0700, Joe Perches wrote: > On Tue, 2020-05-05 at 19:44 +0200, Christian Brauner wrote: > > Jan reported an issue where an interaction between sign-extending clone's > > flag argument on ppc64le and the new CLONE_INTO_CGROUP feature causes > > clone() to consistently fail with EBADF. > [] > > Let's fix this by always capping the upper 32 bits for the legacy clone() > > syscall. This ensures that we can't reach clone3() only features by > > accident via legacy clone as with the sign extension case and also that > > legacy clone() works exactly like before, i.e. ignoring any unknown flags. > > This solution risks no regressions and is also pretty clean. > > > > I've chosen u32 and not unsigned int to visually indicate that we're > > capping this to 32 bits. > > Perhaps use the lower_32_bits macro?
Oh neat, I wasn't aware of this helper since there are no users under kernel/* Christian
