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. 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. Thanks, -- Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
