From: Andrew Morton <akpm@linux-foundation.org>
To: Marco Elver <elver@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>,
Uladzislau Rezki <urezki@gmail.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
kasan-dev@googlegroups.com, Vitaly Wool <vitaly.wool@konsulko.se>,
stable@vger.kernel.org, "Harry Yoo (Oracle)" <harry@kernel.org>
Subject: Re: [PATCH] vmalloc: fix buffer overflow in vrealloc_node_align()
Date: Fri, 24 Apr 2026 06:56:17 -0700 [thread overview]
Message-ID: <20260424065617.5de5751ec5a5c91910d45a28@linux-foundation.org> (raw)
In-Reply-To: <20260420114805.3572606-2-elver@google.com>
On Mon, 20 Apr 2026 13:47:26 +0200 Marco Elver <elver@google.com> wrote:
> Commit 4c5d3365882d ("mm/vmalloc: allow to set node and align in
> vrealloc") added the ability to force a new allocation if the current
> pointer is on the wrong NUMA node, or if an alignment constraint is not
> met, even if the user is shrinking the allocation.
>
> On this path (need_realloc), the code allocates a new object of 'size'
> bytes and then memcpy()s 'old_size' bytes into it. If the request is to
> shrink the object (size < old_size), this results in an out-of-bounds
> write on the new buffer.
>
> Fix this by bounding the copy length by the new allocation size.
AI review is asking questions about the nearby code:
https://sashiko.dev/#/patchset/20260420114805.3572606-2-elver@google.com
next prev parent reply other threads:[~2026-04-24 13:56 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-04-20 11:47 [PATCH] vmalloc: fix buffer overflow in vrealloc_node_align() Marco Elver
2026-04-20 12:17 ` Uladzislau Rezki
2026-04-20 12:21 ` Vlastimil Babka (SUSE)
2026-04-20 13:04 ` Harry Yoo (Oracle)
2026-04-24 13:56 ` Andrew Morton [this message]
2026-04-27 11:02 ` Marco Elver
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