From patchwork Tue Sep 29 18:35:09 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Popov X-Patchwork-Id: 11806533 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 5C34B174A for ; Tue, 29 Sep 2020 18:36:10 +0000 (UTC) Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.kernel.org (Postfix) with SMTP id 9FB2B20754 for ; Tue, 29 Sep 2020 18:36:09 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9FB2B20754 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kernel-hardening-return-20022-patchwork-kernel-hardening=patchwork.kernel.org@lists.openwall.com Received: (qmail 25681 invoked by uid 550); 29 Sep 2020 18:36:00 -0000 Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Delivered-To: mailing list kernel-hardening@lists.openwall.com Received: (qmail 25613 invoked from network); 29 Sep 2020 18:36:00 -0000 X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=MskjPp6ZpujaNwi4yQltgMjSnkxLjmoI3z/cZXeO2Hw=; b=dQgTi/8awkqLewD4o/nji1MdJVDkGt8eXkCjFaZ0G4nIjev3fLdoWdjcdew1ndCGKE SDVllEQzGBs/oqCwaonvH0KdBNJSDGtStGLFE8bHTdv4L37oZKDyXqrq67DlV4C9oNd7 X89va7YXCLYImNSYUpkMlvwydfXoD5aD8XBIxgc+fLggzpLis/if2vyYknVU6qFfwwl+ gSwrx1HjisD//d4QRsq29TSpREEFbyF1iyIjdN9206GjldyspffHSKjHMb7mHqs4rd/B PbZfX5Vu9v7RYYLZQn/gT5U10RRBz+vsJ6gsz4iSGgw0v8t+kX7qtZ3NGXMzNfMureNd YWHA== X-Gm-Message-State: AOAM532weDjp+7MBvDks/igA/c3LeCLj1r2uFl6yHSTa6zbmJhgvwqKt fHyyhOjVaf84AYL+Ho2iKdY= X-Google-Smtp-Source: ABdhPJwrwd83g7bnSyKaLf5bfDcLBH7k0W2piOgi8XJXLrVdkpCHESSboWm1QucjXR4ih++3BiFn+w== X-Received: by 2002:a05:600c:21c4:: with SMTP id x4mr6092766wmj.107.1601404547746; Tue, 29 Sep 2020 11:35:47 -0700 (PDT) From: Alexander Popov To: Kees Cook , Jann Horn , Will Deacon , Andrey Ryabinin , Alexander Potapenko , Dmitry Vyukov , Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , Andrew Morton , Masahiro Yamada , Masami Hiramatsu , Steven Rostedt , Peter Zijlstra , Krzysztof Kozlowski , Patrick Bellasi , David Howells , Eric Biederman , Johannes Weiner , Laura Abbott , Arnd Bergmann , Greg Kroah-Hartman , Daniel Micay , Andrey Konovalov , Matthew Wilcox , Pavel Machek , Valentin Schneider , kasan-dev@googlegroups.com, linux-mm@kvack.org, kernel-hardening@lists.openwall.com, linux-kernel@vger.kernel.org, Alexander Popov Cc: notify@kernel.org Subject: [PATCH RFC v2 2/6] mm/slab: Perform init_on_free earlier Date: Tue, 29 Sep 2020 21:35:09 +0300 Message-Id: <20200929183513.380760-3-alex.popov@linux.com> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200929183513.380760-1-alex.popov@linux.com> References: <20200929183513.380760-1-alex.popov@linux.com> MIME-Version: 1.0 Currently in CONFIG_SLAB init_on_free happens too late, and heap objects go to the heap quarantine being dirty. Lets move memory clearing before calling kasan_slab_free() to fix that. Signed-off-by: Alexander Popov Reviewed-by: Alexander Potapenko --- mm/slab.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/mm/slab.c b/mm/slab.c index 3160dff6fd76..5140203c5b76 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -3414,6 +3414,9 @@ static void cache_flusharray(struct kmem_cache *cachep, struct array_cache *ac) static __always_inline void __cache_free(struct kmem_cache *cachep, void *objp, unsigned long caller) { + if (unlikely(slab_want_init_on_free(cachep))) + memset(objp, 0, cachep->object_size); + /* Put the object into the quarantine, don't touch it for now. */ if (kasan_slab_free(cachep, objp, _RET_IP_)) return; @@ -3432,8 +3435,6 @@ void ___cache_free(struct kmem_cache *cachep, void *objp, struct array_cache *ac = cpu_cache_get(cachep); check_irq_off(); - if (unlikely(slab_want_init_on_free(cachep))) - memset(objp, 0, cachep->object_size); kmemleak_free_recursive(objp, cachep->flags); objp = cache_free_debugcheck(cachep, objp, caller); memcg_slab_free_hook(cachep, virt_to_head_page(objp), objp);