Re: [PATCH] arm64: __clear_user: handle exceptions on strb

From: Catalin Marinas
Date: Thu Nov 13 2014 - 10:21:34 EST


On Thu, Nov 13, 2014 at 03:14:08PM +0000, Kyle McMartin wrote:
> On Thu, Nov 13, 2014 at 03:06:25PM +0000, Catalin Marinas wrote:
> > On Wed, Nov 12, 2014 at 09:07:44PM +0000, Kyle McMartin wrote:
> > > ARM64 currently doesn't fix up faults on the single-byte (strb) case of
> > > __clear_user... which means that we can cause a nasty kernel panic as an
> > > ordinary user with any multiple PAGE_SIZE+1 read from /dev/zero.
> > > i.e.: dd if=/dev/zero of=foo ibs=1 count=1 (or ibs=65537, etc.)
> >
> > Thanks for this, it's been like this for a while. Applied.
> >
>
> Thanks Catalin, if it's not too late, I forgot to add a
> Reported-by: MiloÅ PrchlÃk <mprchlik@xxxxxxxxxx>
> for the initial report of the panic.

I'll add this, I haven't pushed it out yet.

--
Catalin
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