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Date:   Tue, 27 Jul 2021 09:38:17 +0200
From:   Michal Hocko <mhocko@suse.com>
To:     "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc:     Al Viro <viro@zeniv.linux.org.uk>,
        Qualys Security Advisory <qsa@qualys.com>,
        Eric Sandeen <sandeen@redhat.com>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] mm: Make kvmalloc refuse to allocate more than 2GB
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On Wed 21-07-21 19:41:31, Matthew Wilcox wrote:
> It's generally dangerous to allocate such large quantities of memory
> within the kernel owing to our propensity to use 'int' to represent
> a length.  If somebody really needs it, we can add a kvmalloc_large()
> later, but let's default to "You can't allocate that much memory".

I do agree that limiting kvmalloc allocation size is a reasonable thing
to do but I do not really see why we should remove the check from
seq_buf_alloc. Implicitly relying on kvmalloc to workaround a bug that
was in seq_buf code seems like a step backwards to me.
-- 
Michal Hocko
SUSE Labs