Re: Avoiding information leaks between users and between processes by default? [Was: : [PATCH 1/5] prctl: add PR_ISOLATE_BP process control]

2018-01-29 Thread Alan Cox
On Mon, 29 Jan 2018 14:14:46 +0100 Pavel Machek wrote: > On Wed 2018-01-24 20:46:22, Alan Cox wrote: > > > Anyway, no need to add prctl(), if A can ptrace B and B can ptrace A, > > > leaking info between them should not be a big deal. You can probably > > > find existing macros doing neccessary c

Re: Avoiding information leaks between users and between processes by default? [Was: : [PATCH 1/5] prctl: add PR_ISOLATE_BP process control]

2018-01-29 Thread Pavel Machek
On Wed 2018-01-24 20:46:22, Alan Cox wrote: > > Anyway, no need to add prctl(), if A can ptrace B and B can ptrace A, > > leaking info between them should not be a big deal. You can probably > > find existing macros doing neccessary checks. > > Until one of them is security managed so it shouldn't

Re: Avoiding information leaks between users and between processes by default? [Was: : [PATCH 1/5] prctl: add PR_ISOLATE_BP process control]

2018-01-24 Thread Alan Cox
> Anyway, no need to add prctl(), if A can ptrace B and B can ptrace A, > leaking info between them should not be a big deal. You can probably > find existing macros doing neccessary checks. Until one of them is security managed so it shouldn't be able to ptrace the other, or (and this is the nast

Re: Avoiding information leaks between users and between processes by default? [Was: : [PATCH 1/5] prctl: add PR_ISOLATE_BP process control]

2018-01-24 Thread Pavel Machek
Hi! > > On Wed 2018-01-24 09:37:05, Dominik Brodowski wrote: > > > On Wed, Jan 24, 2018 at 07:29:53AM +0100, Martin Schwidefsky wrote: > > > > On Tue, 23 Jan 2018 18:07:19 +0100 > > > > Dominik Brodowski wrote: > > > > > > > > > On Tue, Jan 23, 2018 at 02:07:01PM +0100, Martin Schwidefsky wro

Re: Avoiding information leaks between users and between processes by default? [Was: : [PATCH 1/5] prctl: add PR_ISOLATE_BP process control]

2018-01-24 Thread Alan Cox
On Wed, 24 Jan 2018 09:37:05 +0100 > To my understanding, Linux traditionally tried to aim for the security goal > of avoiding information leaks *between* users[+], probably even between > processes of the same user. It wasn't a guarantee, and there always were Not between processes of the same us

Re: Avoiding information leaks between users and between processes by default? [Was: : [PATCH 1/5] prctl: add PR_ISOLATE_BP process control]

2018-01-24 Thread Martin Schwidefsky
On Wed, 24 Jan 2018 12:15:53 +0100 Pavel Machek wrote: > Hi! > > On Wed 2018-01-24 09:37:05, Dominik Brodowski wrote: > > On Wed, Jan 24, 2018 at 07:29:53AM +0100, Martin Schwidefsky wrote: > > > On Tue, 23 Jan 2018 18:07:19 +0100 > > > Dominik Brodowski wrote: > > > > > > > On Tue, Jan 23

Re: Avoiding information leaks between users and between processes by default? [Was: : [PATCH 1/5] prctl: add PR_ISOLATE_BP process control]

2018-01-24 Thread Pavel Machek
Hi! On Wed 2018-01-24 09:37:05, Dominik Brodowski wrote: > On Wed, Jan 24, 2018 at 07:29:53AM +0100, Martin Schwidefsky wrote: > > On Tue, 23 Jan 2018 18:07:19 +0100 > > Dominik Brodowski wrote: > > > > > On Tue, Jan 23, 2018 at 02:07:01PM +0100, Martin Schwidefsky wrote: > > > > Add the PR_ISOL

Re: Avoiding information leaks between users and between processes by default? [Was: : [PATCH 1/5] prctl: add PR_ISOLATE_BP process control]

2018-01-24 Thread David Woodhouse
On Wed, 2018-01-24 at 09:37 +0100, Dominik Brodowski wrote: > On Wed, Jan 24, 2018 at 07:29:53AM +0100, Martin Schwidefsky wrote: > > > > On Tue, 23 Jan 2018 18:07:19 +0100 > > Dominik Brodowski wrote: > > > > > > > > On Tue, Jan 23, 2018 at 02:07:01PM +0100, Martin Schwidefsky wrote: > > > >

Avoiding information leaks between users and between processes by default? [Was: : [PATCH 1/5] prctl: add PR_ISOLATE_BP process control]

2018-01-24 Thread Dominik Brodowski
On Wed, Jan 24, 2018 at 07:29:53AM +0100, Martin Schwidefsky wrote: > On Tue, 23 Jan 2018 18:07:19 +0100 > Dominik Brodowski wrote: > > > On Tue, Jan 23, 2018 at 02:07:01PM +0100, Martin Schwidefsky wrote: > > > Add the PR_ISOLATE_BP operation to prctl. The effect of the process > > > control is

Re: [PATCH 1/5] prctl: add PR_ISOLATE_BP process control

2018-01-24 Thread Christian Borntraeger
On 01/23/2018 06:07 PM, Dominik Brodowski wrote: > On Tue, Jan 23, 2018 at 02:07:01PM +0100, Martin Schwidefsky wrote: >> Add the PR_ISOLATE_BP operation to prctl. The effect of the process >> control is to make all branch prediction entries created by the execution >> of the user space code of t

Re: [PATCH 1/5] prctl: add PR_ISOLATE_BP process control

2018-01-23 Thread Martin Schwidefsky
On Tue, 23 Jan 2018 18:07:19 +0100 Dominik Brodowski wrote: > On Tue, Jan 23, 2018 at 02:07:01PM +0100, Martin Schwidefsky wrote: > > Add the PR_ISOLATE_BP operation to prctl. The effect of the process > > control is to make all branch prediction entries created by the execution > > of the user s

Re: [PATCH 1/5] prctl: add PR_ISOLATE_BP process control

2018-01-23 Thread Dominik Brodowski
On Tue, Jan 23, 2018 at 02:07:01PM +0100, Martin Schwidefsky wrote: > Add the PR_ISOLATE_BP operation to prctl. The effect of the process > control is to make all branch prediction entries created by the execution > of the user space code of this task not applicable to kernel code or the > code of

[PATCH 1/5] prctl: add PR_ISOLATE_BP process control

2018-01-23 Thread Martin Schwidefsky
Add the PR_ISOLATE_BP operation to prctl. The effect of the process control is to make all branch prediction entries created by the execution of the user space code of this task not applicable to kernel code or the code of any other task. This can be achieved by the architecture specific implement