On Tue, 9 Jan 2018, Josh Poimboeuf wrote: > On Tue, Jan 09, 2018 at 11:44:05AM -0800, Dan Williams wrote: > > On Tue, Jan 9, 2018 at 11:34 AM, Jiri Kosina <jikos@xxxxxxxxxx> wrote: > > > On Fri, 5 Jan 2018, Dan Williams wrote: > > > > > > [ ... snip ... ] > > >> Andi Kleen (1): > > >> x86, barrier: stop speculation for failed access_ok > > >> > > >> Dan Williams (13): > > >> x86: implement nospec_barrier() > > >> [media] uvcvideo: prevent bounds-check bypass via speculative execution > > >> carl9170: prevent bounds-check bypass via speculative execution > > >> p54: prevent bounds-check bypass via speculative execution > > >> qla2xxx: prevent bounds-check bypass via speculative execution > > >> cw1200: prevent bounds-check bypass via speculative execution > > >> Thermal/int340x: prevent bounds-check bypass via speculative execution > > >> ipv6: prevent bounds-check bypass via speculative execution > > >> ipv4: prevent bounds-check bypass via speculative execution > > >> vfs, fdtable: prevent bounds-check bypass via speculative execution > > >> net: mpls: prevent bounds-check bypass via speculative execution > > >> udf: prevent bounds-check bypass via speculative execution > > >> userns: prevent bounds-check bypass via speculative execution > > >> > > >> Mark Rutland (4): > > >> asm-generic/barrier: add generic nospec helpers > > >> Documentation: document nospec helpers > > >> arm64: implement nospec_ptr() > > >> arm: implement nospec_ptr() > > > > > > So considering the recent publication of [1], how come we all of a sudden > > > don't need the barriers in ___bpf_prog_run(), namely for LD_IMM_DW and > > > LDX_MEM_##SIZEOP, and something comparable for eBPF JIT? > > > > > > Is this going to be handled in eBPF in some other way? > > > > > > Without that in place, and considering Jann Horn's paper, it would seem > > > like PTI doesn't really lock it down fully, right? > > > > Here is the latest (v3) bpf fix: > > > > https://patchwork.ozlabs.org/patch/856645/ > > > > I currently have v2 on my 'nospec' branch and will move that to v3 for > > the next update, unless it goes upstream before then. Daniel, I guess you're planning to send this still for 4.15? > That patch seems specific to CONFIG_BPF_SYSCALL. Is the bpf() syscall > the only attack vector? Or are there other ways to run bpf programs > that we should be worried about? Seems like Alexei is probably the only person in the whole universe who isn't CCed here ... let's fix that. Thanks, -- Jiri Kosina SUSE Labs