From patchwork Mon Dec 6 21:44:00 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: andrey.konovalov@linux.dev X-Patchwork-Id: 12695008 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id EAA3AC433EF for ; Mon, 6 Dec 2021 22:01:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=1xnLWUFRTzBX10TgnhCBK/+okayWMAVNKc2Zp6Da3gs=; b=bu/uDtTY2IKCGX /JXTHvq97I5kmDIsS42jb6OCi5AurNMTRg4wfwjRi3sUVhKBWn3tYW5TglTsIfMg0A2qWEF1FyIKG fDHQBC9mXaoG+hUSDqlqsp50ZjIxFwDGbZNbMMAS78FikH62y1K0/70Rd00P/Te1MX1/7Su+HGg1X NSZXjCVmbDhMM4HY0Elwlc5Sc1wmuvzLJ7bZ1G6NNY9XKWVamKjNsS3+ZS+FX9sUkmrMiio0sZaTf c/iOQ3XFCiBAnvQXlcxFT0EJ/58RghL3K1amYBzAQavxGfu0coDQ/Hpri1zJqdxixPyGi17R27Tqa YznFGIPXTB9gi6D56HQw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1muM1g-00658u-SA; Mon, 06 Dec 2021 22:00:01 +0000 Received: from out2.migadu.com ([2001:41d0:2:aacc::]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1muLoR-005zNx-CP for linux-arm-kernel@lists.infradead.org; Mon, 06 Dec 2021 21:46:21 +0000 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=1638827178; 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=4ip+mfiCrUsqaU/ZPq/AUCt3O9J1b1z5H3QxOY+5r30=; b=jpdwDylT/uL4URAlxZowoEzRKnBJtPW77wI4HMlU8g00LVAfw9613B3AicbBk1BI2NRIot K32IXPXhnspxnmJrDkOlWVoY6BtqWM1Svq63bBuOezsDU3FrWLWkFutkZemteUnJR2HKED gwUE9lG6TiioKxiDfBP4kpfsNzfPwXg= From: andrey.konovalov@linux.dev To: Marco Elver , Alexander Potapenko , Vincenzo Frascino , Catalin Marinas , Peter Collingbourne Cc: Andrey Konovalov , Dmitry Vyukov , Andrey Ryabinin , kasan-dev@googlegroups.com, Andrew Morton , linux-mm@kvack.org, Will Deacon , Mark Rutland , linux-arm-kernel@lists.infradead.org, Evgenii Stepanov , linux-kernel@vger.kernel.org, Andrey Konovalov Subject: [PATCH v2 23/34] kasan, vmalloc: add vmalloc support to SW_TAGS Date: Mon, 6 Dec 2021 22:44:00 +0100 Message-Id: <666b9e932dde24df6e1b02493a04530b99ace697.1638825394.git.andreyknvl@google.com> In-Reply-To: References: MIME-Version: 1.0 X-Migadu-Flow: FLOW_OUT X-Migadu-Auth-User: linux.dev X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20211206_134619_788569_9F316AA6 X-CRM114-Status: GOOD ( 14.85 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org From: Andrey Konovalov This patch adds vmalloc tagging support to SW_TAGS KASAN. The changes include: - __kasan_unpoison_vmalloc() now assigns a random pointer tag, poisons the virtual mapping accordingly, and embeds the tag into the returned pointer. - __get_vm_area_node() (used by vmalloc() and vmap()) and pcpu_get_vm_areas() save the tagged pointer into vm_struct->addr (note: not into vmap_area->addr). This requires putting kasan_unpoison_vmalloc() after setup_vmalloc_vm[_locked](); otherwise the latter will overwrite the tagged pointer. The tagged pointer then is naturally propagateed to vmalloc() and vmap(). - vm_map_ram() returns the tagged pointer directly. - Allow enabling KASAN_VMALLOC with SW_TAGS. Signed-off-by: Andrey Konovalov --- Changes v1->v2: - Allow enabling KASAN_VMALLOC with SW_TAGS in this patch. --- include/linux/kasan.h | 17 +++++++++++------ lib/Kconfig.kasan | 2 +- mm/kasan/shadow.c | 6 ++++-- mm/vmalloc.c | 14 ++++++++------ 4 files changed, 24 insertions(+), 15 deletions(-) diff --git a/include/linux/kasan.h b/include/linux/kasan.h index ad4798e77f60..6a2619759e93 100644 --- a/include/linux/kasan.h +++ b/include/linux/kasan.h @@ -423,12 +423,14 @@ void kasan_release_vmalloc(unsigned long start, unsigned long end, unsigned long free_region_start, unsigned long free_region_end); -void __kasan_unpoison_vmalloc(const void *start, unsigned long size); -static __always_inline void kasan_unpoison_vmalloc(const void *start, - unsigned long size) +void * __must_check __kasan_unpoison_vmalloc(const void *start, + unsigned long size); +static __always_inline void * __must_check kasan_unpoison_vmalloc( + const void *start, unsigned long size) { if (kasan_enabled()) - __kasan_unpoison_vmalloc(start, size); + return __kasan_unpoison_vmalloc(start, size); + return (void *)start; } void __kasan_poison_vmalloc(const void *start, unsigned long size); @@ -453,8 +455,11 @@ static inline void kasan_release_vmalloc(unsigned long start, unsigned long free_region_start, unsigned long free_region_end) { } -static inline void kasan_unpoison_vmalloc(const void *start, unsigned long size) -{ } +static inline void *kasan_unpoison_vmalloc(const void *start, + unsigned long size, bool unique) +{ + return (void *)start; +} static inline void kasan_poison_vmalloc(const void *start, unsigned long size) { } diff --git a/lib/Kconfig.kasan b/lib/Kconfig.kasan index cdc842d090db..3f144a87f8a3 100644 --- a/lib/Kconfig.kasan +++ b/lib/Kconfig.kasan @@ -179,7 +179,7 @@ config KASAN_TAGS_IDENTIFY config KASAN_VMALLOC bool "Back mappings in vmalloc space with real shadow memory" - depends on KASAN_GENERIC && HAVE_ARCH_KASAN_VMALLOC + depends on (KASAN_GENERIC || KASAN_SW_TAGS) && HAVE_ARCH_KASAN_VMALLOC help By default, the shadow region for vmalloc space is the read-only zero page. This means that KASAN cannot detect errors involving diff --git a/mm/kasan/shadow.c b/mm/kasan/shadow.c index fa0c8a750d09..4ca280a96fbc 100644 --- a/mm/kasan/shadow.c +++ b/mm/kasan/shadow.c @@ -475,12 +475,14 @@ void kasan_release_vmalloc(unsigned long start, unsigned long end, } } -void __kasan_unpoison_vmalloc(const void *start, unsigned long size) +void *__kasan_unpoison_vmalloc(const void *start, unsigned long size) { if (!is_vmalloc_or_module_addr(start)) - return; + return (void *)start; + start = set_tag(start, kasan_random_tag()); kasan_unpoison(start, size, false); + return (void *)start; } /* diff --git a/mm/vmalloc.c b/mm/vmalloc.c index a059b3100c0a..7be18b292679 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -2208,7 +2208,7 @@ void *vm_map_ram(struct page **pages, unsigned int count, int node) mem = (void *)addr; } - kasan_unpoison_vmalloc(mem, size); + mem = kasan_unpoison_vmalloc(mem, size); if (vmap_pages_range(addr, addr + size, PAGE_KERNEL, pages, PAGE_SHIFT) < 0) { @@ -2441,10 +2441,10 @@ static struct vm_struct *__get_vm_area_node(unsigned long size, return NULL; } - kasan_unpoison_vmalloc((void *)va->va_start, requested_size); - setup_vmalloc_vm(area, va, flags, caller); + area->addr = kasan_unpoison_vmalloc(area->addr, requested_size); + return area; } @@ -3752,9 +3752,6 @@ struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets, for (area = 0; area < nr_vms; area++) { if (kasan_populate_vmalloc(vas[area]->va_start, sizes[area])) goto err_free_shadow; - - kasan_unpoison_vmalloc((void *)vas[area]->va_start, - sizes[area]); } /* insert all vm's */ @@ -3767,6 +3764,11 @@ struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets, } spin_unlock(&vmap_area_lock); + /* mark allocated areas as accessible */ + for (area = 0; area < nr_vms; area++) + vms[area]->addr = kasan_unpoison_vmalloc(vms[area]->addr, + vms[area]->size); + kfree(vas); return vms;