[prev in list] [next in list] [prev in thread] [next in thread] 

List:       linux-api
Subject:    Re: [PATCH v26 8/9] x86/vdso/32: Add ENDBR to __kernel_vsyscall entry point
From:       Kees Cook <keescook () chromium ! org>
Date:       2021-04-28 20:39:07
Message-ID: 202104281339.F0CA6CA3E () keescook
[Download RAW message or body]

On Tue, Apr 27, 2021 at 01:47:19PM -0700, Yu-cheng Yu wrote:
> From: "H.J. Lu" <hjl.tools@gmail.com>
> 
> ENDBR is a special new instruction for the Indirect Branch Tracking (IBT)
> component of CET.  IBT prevents attacks by ensuring that (most) indirect
> branches and function calls may only land at ENDBR instructions.  Branches
> that don't follow the rules will result in control flow (#CF) exceptions.
> 
> ENDBR is a noop when IBT is unsupported or disabled.  Most ENDBR
> instructions are inserted automatically by the compiler, but branch
> targets written in assembly must have ENDBR added manually.
> 
> Add that to __kernel_vsyscall entry point.
> 
> Signed-off-by: H.J. Lu <hjl.tools@gmail.com>

Reviewed-by: Kees Cook <keescook@chromium.org>

-- 
Kees Cook
[prev in list] [next in list] [prev in thread] [next in thread]