From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 609C4C433EF for ; Mon, 13 Dec 2021 22:16:11 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 0853D6B0081; Mon, 13 Dec 2021 16:59:53 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 034636B0082; Mon, 13 Dec 2021 16:59:52 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E3DDB6B0083; Mon, 13 Dec 2021 16:59:52 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay028.a.hostedemail.com [64.99.140.28]) by kanga.kvack.org (Postfix) with ESMTP id D57526B0081 for ; Mon, 13 Dec 2021 16:59:52 -0500 (EST) Received: from smtpin02.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id A9D9C604F9 for ; Mon, 13 Dec 2021 21:59:42 +0000 (UTC) X-FDA: 78914138604.02.C7B6977 Received: from mail-io1-f45.google.com (mail-io1-f45.google.com [209.85.166.45]) by imf01.hostedemail.com (Postfix) with ESMTP id D400940011 for ; Mon, 13 Dec 2021 21:59:38 +0000 (UTC) Received: by mail-io1-f45.google.com with SMTP id z26so20588856iod.10 for ; Mon, 13 Dec 2021 13:59:42 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=MRKR0iLm5s05rmkpI4jYkAhFh/8IVKgubKuDuwtAGZo=; b=BXPU2MKMaLSHJTBj5Fw+l85b1jn/pzQUVpMyk8A6WadXKXL91eftH/hXryN1YD02Bk yYJjKVCttnWtAu34nnoYtl5SDJsQBAt24aG9HH+TiEvggjxBVb1f6nz64e43tegiJtUy ns/h5Ks0DmU73WQJ8BXaSDsLcHJ8yT40QiXVFGWr3mhrvkLaS6wQEDtFg62pl+pgn4JV lam9uUklYEZLohMos1Kkdttx6dgFB4F2IKNStg8jD/r9JG9/TnOa2YgtxrOa4PfUcn4F UGpSoWkA//ZgRBnLkV6Sg7TxHWcmwoCYnStDA3T1VIeYXgaa7VmUFGF3VWze/Ab75IBm 3HAg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=MRKR0iLm5s05rmkpI4jYkAhFh/8IVKgubKuDuwtAGZo=; b=KIov81JMQJ/DakM9RB2CQl+Gjd3Gysn7DQymkJAHwjbZQCswhCp5+AGNeUz6fONa3t dsR/W1bC3Atrv6ZMNpQ8tvKi/YCeujOGQm6s79letElNXGCGqTmD7LkOp6WbTEkyW5Fs j6P6GmcBM16f/+xsKq0r28Pss3yPVlf3msymjA0EMRiheKA3h11wJQX3/Rins9vR21LB 9zx/jJaOmcO0sDy1tjgA2tkQW+a64Co5pPiiwHmF2E247HqmMF6wbSkEWUqub0OFKkt+ newZiTbiOa8+QWn91mJHB06Z06ZFoUvd00NPyHVwl9Ogv83MFHyeyLkf83DlhYpNadMH ArGw== X-Gm-Message-State: AOAM533hf5Eg9AwYHrI+LJzfVdYOywl/mvFg6Nt4o99RZuetIIOzutw3 C82RZ7JkcR0bKb4j0VXO2Wwi3vmu4WsxWOLCdbM= X-Google-Smtp-Source: ABdhPJxKp/i/u1m5HrD6sit7Rz5BFQRyACLGkQ1BCEa+r9UaBHJfr/S2oR06BO7c2NWiVg/7Z7ItGu9Si9PxaCbBSuU= X-Received: by 2002:a05:6602:2c94:: with SMTP id i20mr967459iow.99.1639432781773; Mon, 13 Dec 2021 13:59:41 -0800 (PST) MIME-Version: 1.0 References: In-Reply-To: From: Andrey Konovalov Date: Mon, 13 Dec 2021 22:59:30 +0100 Message-ID: Subject: Re: [PATCH mm v3 23/38] kasan, arm64: reset pointer tags of vmapped stacks To: Vincenzo Frascino , Catalin Marinas Cc: Marco Elver , Alexander Potapenko , Andrew Morton , Dmitry Vyukov , Andrey Ryabinin , kasan-dev , Linux Memory Management List , Will Deacon , Mark Rutland , Linux ARM , Peter Collingbourne , Evgenii Stepanov , LKML , Andrey Konovalov , andrey.konovalov@linux.dev Content-Type: text/plain; charset="UTF-8" X-Stat-Signature: 1fmuatyqqq8h14cye7mw75p96a39zd4i Authentication-Results: imf01.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=BXPU2MKM; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (imf01.hostedemail.com: domain of andreyknvl@gmail.com designates 209.85.166.45 as permitted sender) smtp.mailfrom=andreyknvl@gmail.com X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: D400940011 X-HE-Tag: 1639432778-974123 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Mon, Dec 13, 2021 at 10:54 PM wrote: > > From: Andrey Konovalov > > Once tag-based KASAN modes start tagging vmalloc() allocations, > kernel stacks start getting tagged if CONFIG_VMAP_STACK is enabled. > > Reset the tag of kernel stack pointers after allocation in > arch_alloc_vmap_stack(). > > For SW_TAGS KASAN, when CONFIG_KASAN_STACK is enabled, the > instrumentation can't handle the SP register being tagged. > > For HW_TAGS KASAN, there's no instrumentation-related issues. However, > the impact of having a tagged SP register needs to be properly evaluated, > so keep it non-tagged for now. > > Note, that the memory for the stack allocation still gets tagged to > catch vmalloc-into-stack out-of-bounds accesses. > > Signed-off-by: Andrey Konovalov > > --- > > Changes v2->v3: > - Add this patch. > --- > arch/arm64/include/asm/vmap_stack.h | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/arch/arm64/include/asm/vmap_stack.h b/arch/arm64/include/asm/vmap_stack.h > index 894e031b28d2..20873099c035 100644 > --- a/arch/arm64/include/asm/vmap_stack.h > +++ b/arch/arm64/include/asm/vmap_stack.h > @@ -17,10 +17,13 @@ > */ > static inline unsigned long *arch_alloc_vmap_stack(size_t stack_size, int node) > { > + void *p; > + > BUILD_BUG_ON(!IS_ENABLED(CONFIG_VMAP_STACK)); > > - return __vmalloc_node(stack_size, THREAD_ALIGN, THREADINFO_GFP, node, > + p = __vmalloc_node(stack_size, THREAD_ALIGN, THREADINFO_GFP, node, > __builtin_return_address(0)); > + return kasan_reset_tag(p); > } > > #endif /* __ASM_VMAP_STACK_H */ > -- > 2.25.1 > Catalin, Vincenzo, This is a new patch added in v3. Could you PTAL? Thanks!