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Date: Sat, 26 Apr 2025 12:17:28 +0200
From: Danilo Krummrich <dakr@kernel.org>
To: Kees Cook <kees@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	Erhard Furtner <erhard_f@mailbox.org>,
	Michal Hocko <mhocko@suse.com>, Vlastimil Babka <vbabka@suse.cz>,
	Uladzislau Rezki <urezki@gmail.com>, linux-mm@kvack.org,
	linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org
Subject: Re: [PATCH v2] mm: vmalloc: Support more granular vrealloc() sizing
Message-ID: <aAyyuCz6Y1bliBbn@pollux>
References: <20250426001105.it.679-kees@kernel.org>
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In-Reply-To: <20250426001105.it.679-kees@kernel.org>

On Fri, Apr 25, 2025 at 05:11:07PM -0700, Kees Cook wrote:
> Introduce struct vm_struct::requested_size so that the requested
> (re)allocation size is retained separately from the allocated area
> size. This means that KASAN will correctly poison the correct spans
> of requested bytes. This also means we can support growing the usable
> portion of an allocation that can already be supported by the existing
> area's existing allocation.
> 
> Reported-by: Erhard Furtner <erhard_f@mailbox.org>
> Closes: https://lore.kernel.org/all/20250408192503.6149a816@outsider.home/
> Fixes: 3ddc2fefe6f3 ("mm: vmalloc: implement vrealloc()")
> Signed-off-by: Kees Cook <kees@kernel.org>

Reviewed-by: Danilo Krummrich <dakr@kernel.org>