Re: [PATCH] kmsg: Use vmalloc instead of kmalloc when writing

From: Greg KH
Date: Fri Mar 30 2012 - 11:30:19 EST

On Fri, Mar 30, 2012 at 01:04:27PM -0400, Sasha Levin wrote:
> There are no size checks in kmsg_write(), and we try allocating enough
> memory to store everything userspace gave us, which may be too much for
> kmalloc to allocate.

Really? Have you seen this fail? As only root can do this, is this
really a problem?

> One option would be to limit it to something, but we can't come up with
> a number that would make sense.
> Instead, just use vmalloc so that nothing would break with large amounts
> of data.

Are you sure this will work properly? Have you tested it with large
amounts of data?


greg k-h
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