Re: [PATCH 1/3] usercopy: Handle vm_map_ram() areas

[Uladzislau Rezki <urezki@gmail.com>]

> On 06/13/22 at 12:00pm, Uladzislau Rezki wrote:
> > > vmalloc does not allocate a vm_struct for vm_map_ram() areas.  That causes
> > > us to deny usercopies from those areas.  This affects XFS which uses
> > > vm_map_ram() for its directories.
> > > 
> > > Fix this by calling find_vmap_area() instead of find_vm_area().
> > > 
> > > Fixes: 0aef499f3172 ("mm/usercopy: Detect vmalloc overruns")
> > > Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
> > > ---
> > >  include/linux/vmalloc.h | 1 +
> > >  mm/usercopy.c           | 8 +++++---
> > >  mm/vmalloc.c            | 2 +-
> > >  3 files changed, 7 insertions(+), 4 deletions(-)
> > > 
> > > diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h
> > > index b159c2789961..096d48aa3437 100644
> > > --- a/include/linux/vmalloc.h
> > > +++ b/include/linux/vmalloc.h
> > > @@ -215,6 +215,7 @@ extern struct vm_struct *__get_vm_area_caller(unsigned long size,
> > >  void free_vm_area(struct vm_struct *area);
> > >  extern struct vm_struct *remove_vm_area(const void *addr);
> > >  extern struct vm_struct *find_vm_area(const void *addr);
> > > +struct vmap_area *find_vmap_area(unsigned long addr);
> > Make it "extern" since it becomes globally visible?
> 
> extern is not suggested any more to add for function declaration in
> header file, and removing it doesn't impact thing.
> 
OK, thanks for the hint: Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com>

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Uladzislau Rezki