On 28.01.20 00:19, Kees Cook wrote: > On Thu, Jan 23, 2020 at 09:14:20AM +0100, Jiri Slaby wrote: >> On 14. 11. 19, 22:27, Kees Cook wrote: >>> On Tue, Nov 12, 2019 at 01:21:54PM -0800, Kees Cook wrote: >>>> How is iucv the only network protocol that has run into this? Do others >>>> use a bounce buffer? >>> >>> Another solution would be to use a dedicated kmem cache (instead of the >>> shared kmalloc dma one)? >> >> Has there been any conclusion to this thread yet? For the time being, we >> disabled HARDENED_USERCOPY on s390... >> >> https://lore.kernel.org/kernel-hardening/9519edb7-456a-a2fa-659e-3e5a1ff89466@xxxxxxx/ > > I haven't heard anything new. What did people think of a separate kmem > cache? > Adding Julian and Ursula. A separate kmem cache for iucv might be indeed a solution for the user hardening issue. On the other hand not marking the DMA caches still seems questionable. For reference https://bugzilla.suse.com/show_bug.cgi?id=1156053 the kernel hardening now triggers a warning.