Re: [PATCH v2] pipe: Fail cleanly when root tries F_SETPIPE_SZ withbig size

From: Sasha Levin
Date: Fri Dec 02 2011 - 12:47:20 EST


Al, Ping?

On Sat, 2011-11-19 at 10:06 +0200, Pekka Enberg wrote:
> On Sat, Nov 19, 2011 at 9:34 AM, Sasha Levin <levinsasha928@xxxxxxxxx> wrote:
> > When a user with the CAP_SYS_RESOURCE cap tries to F_SETPIPE_SZ a pipe with
> > size bigger than what kmalloc() can alloc it spits out an ugly warning:
>
> [snip]
>
> > Instead, make kcalloc() handle the overflow case and fail quietly.
> >
> > Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx>
> > Cc: Pekka Enberg <penberg@xxxxxxxxxx>
> > Cc: linux-fsdevel@xxxxxxxxxxxxxxx
> > Signed-off-by: Sasha Levin <levinsasha928@xxxxxxxxx>
>
> Acked-by: Pekka Enberg <penberg@xxxxxxxxxx>
>
> > ---
> > fs/pipe.c | 2 +-
> > 1 files changed, 1 insertions(+), 1 deletions(-)
> >
> > diff --git a/fs/pipe.c b/fs/pipe.c
> > index 4065f07..3e38dc6 100644
> > --- a/fs/pipe.c
> > +++ b/fs/pipe.c
> > @@ -1137,7 +1137,7 @@ static long pipe_set_size(struct pipe_inode_info *pipe, unsigned long nr_pages)
> > if (nr_pages < pipe->nrbufs)
> > return -EBUSY;
> >
> > - bufs = kcalloc(nr_pages, sizeof(struct pipe_buffer), GFP_KERNEL);
> > + bufs = kcalloc(nr_pages, sizeof(struct pipe_buffer), GFP_KERNEL | __GFP_NOWARN);
> > if (unlikely(!bufs))
> > return -ENOMEM;
> >
> > --
> > 1.7.8.rc1
> >
> > --
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> >

--

Sasha.

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