lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Tue, 12 Jan 2021 18:45:08 +0100 From: Oleg Nesterov <oleg@...hat.com> To: Michal Hocko <mhocko@...e.com> Cc: Suren Baghdasaryan <surenb@...gle.com>, akpm@...ux-foundation.org, jannh@...gle.com, keescook@...omium.org, jeffv@...gle.com, minchan@...nel.org, shakeelb@...gle.com, rientjes@...gle.com, edgararriaga@...gle.com, timmurray@...gle.com, linux-mm@...ck.org, selinux@...r.kernel.org, linux-api@...r.kernel.org, linux-kernel@...r.kernel.org, kernel-team@...roid.com Subject: Re: [PATCH v2 1/1] mm/madvise: replace ptrace attach requirement for process_madvise On 01/12, Michal Hocko wrote: > > On Mon 11-01-21 09:06:22, Suren Baghdasaryan wrote: > > > What we want is the ability for one process to influence another process > > in order to optimize performance across the entire system while leaving > > the security boundary intact. > > Replace PTRACE_MODE_ATTACH with a combination of PTRACE_MODE_READ > > and CAP_SYS_NICE. PTRACE_MODE_READ to prevent leaking ASLR metadata > > and CAP_SYS_NICE for influencing process performance. > > I have to say that ptrace modes are rather obscure to me. So I cannot > really judge whether MODE_READ is sufficient. My understanding has > always been that this is requred to RO access to the address space. But > this operation clearly has a visible side effect. Do we have any actual > documentation for the existing modes? > > I would be really curious to hear from Jann and Oleg (now Cced). Can't comment, sorry. I never understood these security checks and never tried. IIUC only selinux/etc can treat ATTACH/READ differently and I have no idea what is the difference. Oleg.
Powered by blists - more mailing lists