On Wed, Jun 14, 2023 at 12:17:26AM -0700, Christoph Hellwig wrote: > On Tue, Jun 13, 2023 at 08:09:14AM +0200, Dmitry Vyukov wrote: > > I don't question there are use cases for the flag, but there are use > > cases for the config as well. > > > > Some distros may want a guarantee that this does not happen as it > > compromises lockdown and kernel integrity (on par with unsigned module > > loading). > > For fuzzing systems it also may be hard to ensure fine-grained > > argument constraints, it's much easier and more reliable to prohibit > > it on config level. > > I'm fine with a config option enforcing write blocking for any > BLK_OPEN_EXCL open. Maybe the way to it is to: > > a) have an option to prevent any writes to exclusive openers, including > a run-time version to enable it I really would wish we don't make this runtime configurable. Build time and boot time yes but toggling it at runtime makes this already a lot less interesting.