Re: [PATCH 4.4 037/107] x86/mm: Factor out LDT init from context init

[Greg Kroah-Hartman]

On Sat, Aug 25, 2018 at 12:44:10AM +0100, Ben Hutchings wrote:
> On Mon, 2018-07-23 at 14:41 +0200, Greg Kroah-Hartman wrote:
> > 4.4-stable review patch.  If anyone has any objections, please let me know.
> > 
> > ------------------
> > 
> > From: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
> > 
> > commit 39a0526fb3f7d93433d146304278477eb463f8af upstream
> [...]
> > --- a/arch/x86/include/asm/mmu_context.h
> > +++ b/arch/x86/include/asm/mmu_context.h
> [...]
> > +static inline int init_new_context(struct task_struct *tsk,
> > +				   struct mm_struct *mm)
> > +{
> > +	init_new_context_ldt(tsk, mm);
> > +	return 0;
> > +}
> [...]
> 
> This hides errors from init_new_context_ldt(), which is very bad.
> Fixed upstream by:
> 
> commit ccd5b3235180eef3cfec337df1c8554ab151b5cc
> Author: Eric Biggers <ebiggers@xxxxxxxxxx>
> Date:   Thu Aug 24 10:50:29 2017 -0700
> 
>     x86/mm: Fix use-after-free of ldt_struct
> 
> Ben.

Good catch, now applied, thanks.

greg k-h