Re: [PATCH RFC v2] slab: introduce kmalloc_array

From: Christoph Lameter
Date: Tue Feb 14 2012 - 11:34:48 EST


On Tue, 14 Feb 2012, Xi Wang wrote:

> On Feb 14, 2012, at 10:02 AM, Christoph Lameter wrote:
> > We could also catch these issues with BUG() or WARN_ON() and then return
> > zero.
>
> You cannot have SAFE_ARRAY_SIZE return 0 when an integer overflow
> occurs.

You can if you check the results later. A zero size return would be an
indication of an error. No need to pass it on to kmalloc.

> Besides, BUG() still allows DoS attacks and WARN_ON() would flood
> the log, especially if n is controlled from user space. Neither
> seems appropriate here.

We have means at various level to control the "flood."

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