From nobody Fri Dec 19 14:24:59 2025 Received: from out-179.mta0.migadu.com (out-179.mta0.migadu.com [91.218.175.179]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CC21F3D0AB for ; Tue, 19 Dec 2023 22:31:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="Kt1rNfuv" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1703025084; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=KVsX1wYh/u3bsgXc0v6541Y+g0kgoewEBIuD2sVrVOE=; b=Kt1rNfuvx7+wT5H8UNOgwHCeTbOEvaDygKRpZZi3u1FYmus+bD/11ubTVW79B+oIdiaNwz JlwOYJnlQA+xJy+dqmZh3LmC25rgn5CNTohHAkyMco9Blc+/P3IIuddLLDTvM6CJy8A9+O KeuWbai25yfJ/zAiqqyvZxcC5VTNrDs= From: andrey.konovalov@linux.dev To: Marco Elver , Alexander Potapenko Cc: Andrey Konovalov , Dmitry Vyukov , Andrey Ryabinin , kasan-dev@googlegroups.com, Evgenii Stepanov , Breno Leitao , Alexander Lobakin , Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andrey Konovalov Subject: [PATCH mm 13/21] mempool: skip slub_debug poisoning when KASAN is enabled Date: Tue, 19 Dec 2023 23:28:57 +0100 Message-Id: <98a4b1617e8ceeb266ef9a46f5e8c7f67a563ad2.1703024586.git.andreyknvl@google.com> In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Migadu-Flow: FLOW_OUT Content-Type: text/plain; charset="utf-8" From: Andrey Konovalov With the changes in the following patch, KASAN starts saving its metadata within freed mempool elements. Thus, skip slub_debug poisoning and checking of mempool elements when KASAN is enabled. Corruptions of freed mempool elements will be detected by KASAN anyway. Signed-off-by: Andrey Konovalov --- Changes RFC->v1: - This is a new patch. --- mm/mempool.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/mm/mempool.c b/mm/mempool.c index 7e1c729f292b..1fd39478c85e 100644 --- a/mm/mempool.c +++ b/mm/mempool.c @@ -56,6 +56,10 @@ static void __check_element(mempool_t *pool, void *eleme= nt, size_t size) =20 static void check_element(mempool_t *pool, void *element) { + /* Skip checking: KASAN might save its metadata in the element. */ + if (kasan_enabled()) + return; + /* Mempools backed by slab allocator */ if (pool->free =3D=3D mempool_kfree) { __check_element(pool, element, (size_t)pool->pool_data); @@ -81,6 +85,10 @@ static void __poison_element(void *element, size_t size) =20 static void poison_element(mempool_t *pool, void *element) { + /* Skip poisoning: KASAN might save its metadata in the element. */ + if (kasan_enabled()) + return; + /* Mempools backed by slab allocator */ if (pool->alloc =3D=3D mempool_kmalloc) { __poison_element(element, (size_t)pool->pool_data); --=20 2.25.1