On Thu, 29 Nov 2018, Peter Zijlstra wrote: > > int3 isn’t IST anymore, so the int3 instruction conditionally > > subtracts 8 from RSP and then pushes SS, etc. So my email was > > obviously wrong wrt “cs”, but you’re still potentially overwriting the > > int3 IRET frame. > > ARGH!.. > > can't we 'fix' that again? The alternative is moving that IRET-frame and > fixing everything up, which is going to be fragile, ugly and such > things more. > > Commit d8ba61ba58c8 ("x86/entry/64: Don't use IST entry for #BP stack") > doesn't list any strong reasons for why it should NOT be an IST.
It's CVE-2018-8897. -- Jiri Kosina SUSE Labs