Am Freitag, 22. Dezember 2017, 08:36:07 CET schrieb Herbert Xu: Hi Herbert, > On Tue, Dec 19, 2017 at 07:25:04AM +0100, Stephan Müller wrote: > > The user space interface allows specifying the type and the mask field > > used to allocate the cipher. As user space can precisely select the > > desired cipher by using either the name or the driver name, additional > > selection options for cipher are not considered necessary and relevant > > for user space. > > > > This fixes a bug where user space is able to cause one cipher to be > > registered multiple times potentially exhausting kernel memory. > > > > Reported-by: syzbot <syzkaller@xxxxxxxxxxxxxxxx> > > Cc: <stable@xxxxxxxxxxxxxxx> > > Signed-off-by: Stephan Mueller <smueller@xxxxxxxxxx> > > This will break users of CRYPTO_ALG_KERN_DRIVER_ONLY. I think > we should add CRYPTO_ALG_TESTED to the blacklist since there is > no sane reason to use it here. Shouldn't we then rather use a white list instead of a black list? > > Most other problems however would be bugs in the template code. > The first thing a template does when it creates an instance is > to check whether the resulting algorithm would fulfil the requested > type/mask using crypto_check_attr_type. So if that's not working > then we should fix it there as it may also be triggered via other > code paths that can create instances. I think I understand that, but does user space need to utilize this logic? > > Thanks, Ciao Stephan
