From patchwork Tue Nov 27 16:55:39 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrey Konovalov X-Patchwork-Id: 10700933 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id C99B9109C for ; Tue, 27 Nov 2018 16:56:32 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B73072C446 for ; Tue, 27 Nov 2018 16:56:32 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id AA3E42C4A8; Tue, 27 Nov 2018 16:56:32 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.5 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI, USER_IN_DEF_DKIM_WL autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8540B2C4A4 for ; Tue, 27 Nov 2018 16:56:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729644AbeK1DzB (ORCPT ); Tue, 27 Nov 2018 22:55:01 -0500 Received: from mail-wm1-f65.google.com ([209.85.128.65]:40037 "EHLO mail-wm1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731802AbeK1DzA (ORCPT ); Tue, 27 Nov 2018 22:55:00 -0500 Received: by mail-wm1-f65.google.com with SMTP id q26so22893427wmf.5 for ; Tue, 27 Nov 2018 08:56:28 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=BhY1iQFDZFZ0u+IiVAFsds0hu0VM1uAnvbg+4E10gFc=; b=FKNwBJWjoGF0o0RluRjfVYjY6gb1EHWHFwlx1GtlFYi3gmsAhj3FvzadOKaUtBgCDl iuUhmCEmC14IZjS3CyH+H03H1+3axzjpLP/UAqtYkoD5+/UZ6sXTjP48fF4u7TCjxQWm KPQPVjZrFwzT97FFJ4wa23N6ej1AHkWdr48wJ2p4GlhIMOiFwA4ar/dziT5l5Gi1RpGz 5iGAAuwTJDLLORwagOFqJ58DjS7ZVLHw5GOSze3YCWO8O5KHG77oUYdUKZMEil/nAVuL NAG8VyMDWbHxuvur9nja2fypLzc7l34wcoA7tRug/JwDuFnBkd91iwYdbCEGztgklcGi o3cw== 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=BhY1iQFDZFZ0u+IiVAFsds0hu0VM1uAnvbg+4E10gFc=; b=ZsqrqF9hMlIk9bpglc9XZp/hOtgfKzhwG4KyR/NDIgELO1BzY5sVtL6pjR31AOKxR/ Fdt6fKCYPFpy7XeX4zbjvXl4b9X8aM9tI4C+KnMinM0VOo4iqZz+U5AdSsMrjxE74xFy lQuojlubOvAxxg5ExwcqpDcOTYxK0ncOrQ4l3tgCnRlsUOmgtIF4OUUbGMYzeyeAsfRx opBUO99lzSgTKgkaBuwPBTTwynTjRZT+dmdnsx1ikwiCr7xzK03A7RA6Lu38eQ3vsJ/8 2Qj9RWjixeICize324f4uN1SvmOdDph0g0xSXR9edcA2aUuUh3Fyu9vMZliO4LCrg439 6uZw== X-Gm-Message-State: AA+aEWYXF/qaWH6mr86MjOxM9RT6r5qA+pddXNNwiLeZZ2DU/+6abVKU YBP5qTXKq4fxVLHJH3MwHAQ8+g== X-Google-Smtp-Source: AFSGD/WJTtcUbR+qy0BJljY84iI1qGuVqSXNIJRrm7uO0xBr+kj+JN0LMXJ5/M7JOAtEAav+sJH2RQ== X-Received: by 2002:a1c:8d8e:: with SMTP id p136mr2541985wmd.74.1543337787930; Tue, 27 Nov 2018 08:56:27 -0800 (PST) Received: from andreyknvl0.muc.corp.google.com ([2a00:79e0:15:10:3180:41f8:3010:ff61]) by smtp.gmail.com with ESMTPSA id k73sm6383099wmd.36.2018.11.27.08.56.26 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 27 Nov 2018 08:56:27 -0800 (PST) From: Andrey Konovalov To: Andrey Ryabinin , Alexander Potapenko , Dmitry Vyukov , Catalin Marinas , Will Deacon , Christoph Lameter , Andrew Morton , Mark Rutland , Nick Desaulniers , Marc Zyngier , Dave Martin , Ard Biesheuvel , "Eric W . Biederman" , Ingo Molnar , Paul Lawrence , Geert Uytterhoeven , Arnd Bergmann , "Kirill A . Shutemov" , Greg Kroah-Hartman , Kate Stewart , Mike Rapoport , kasan-dev@googlegroups.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-sparse@vger.kernel.org, linux-mm@kvack.org, linux-kbuild@vger.kernel.org Cc: Kostya Serebryany , Evgeniy Stepanov , Lee Smith , Ramana Radhakrishnan , Jacob Bramley , Ruben Ayrapetyan , Jann Horn , Mark Brand , Chintan Pandya , Vishwath Mohan , Andrey Konovalov Subject: [PATCH v12 21/25] kasan, mm, arm64: tag non slab memory allocated via pagealloc Date: Tue, 27 Nov 2018 17:55:39 +0100 Message-Id: <6c1004acf28880f6a5cc7d2f974ba08adb2853ea.1543337629.git.andreyknvl@google.com> X-Mailer: git-send-email 2.20.0.rc0.387.gc7a69e6b6c-goog In-Reply-To: References: MIME-Version: 1.0 Sender: linux-kbuild-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Tag-based KASAN doesn't check memory accesses through pointers tagged with 0xff. When page_address is used to get pointer to memory that corresponds to some page, the tag of the resulting pointer gets set to 0xff, even though the allocated memory might have been tagged differently. For slab pages it's impossible to recover the correct tag to return from page_address, since the page might contain multiple slab objects tagged with different values, and we can't know in advance which one of them is going to get accessed. For non slab pages however, we can recover the tag in page_address, since the whole page was marked with the same tag. This patch adds tagging to non slab memory allocated with pagealloc. To set the tag of the pointer returned from page_address, the tag gets stored to page->flags when the memory gets allocated. Reviewed-by: Andrey Ryabinin Reviewed-by: Dmitry Vyukov Signed-off-by: Andrey Konovalov --- arch/arm64/include/asm/memory.h | 8 +++++++- include/linux/mm.h | 29 +++++++++++++++++++++++++++++ include/linux/page-flags-layout.h | 10 ++++++++++ mm/cma.c | 11 +++++++++++ mm/kasan/common.c | 15 +++++++++++++-- mm/page_alloc.c | 1 + mm/slab.c | 2 +- 7 files changed, 72 insertions(+), 4 deletions(-) diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h index 5fe2353f111b..7db28404609b 100644 --- a/arch/arm64/include/asm/memory.h +++ b/arch/arm64/include/asm/memory.h @@ -314,7 +314,13 @@ static inline void *phys_to_virt(phys_addr_t x) #define __virt_to_pgoff(kaddr) (((u64)(kaddr) & ~PAGE_OFFSET) / PAGE_SIZE * sizeof(struct page)) #define __page_to_voff(kaddr) (((u64)(kaddr) & ~VMEMMAP_START) * PAGE_SIZE / sizeof(struct page)) -#define page_to_virt(page) ((void *)((__page_to_voff(page)) | PAGE_OFFSET)) +#define page_to_virt(page) ({ \ + unsigned long __addr = \ + ((__page_to_voff(page)) | PAGE_OFFSET); \ + __addr = __tag_set(__addr, page_kasan_tag(page)); \ + ((void *)__addr); \ +}) + #define virt_to_page(vaddr) ((struct page *)((__virt_to_pgoff(vaddr)) | VMEMMAP_START)) #define _virt_addr_valid(kaddr) pfn_valid((((u64)(kaddr) & ~PAGE_OFFSET) \ diff --git a/include/linux/mm.h b/include/linux/mm.h index 5411de93a363..b4d01969e700 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -804,6 +804,7 @@ vm_fault_t finish_mkwrite_fault(struct vm_fault *vmf); #define NODES_PGOFF (SECTIONS_PGOFF - NODES_WIDTH) #define ZONES_PGOFF (NODES_PGOFF - ZONES_WIDTH) #define LAST_CPUPID_PGOFF (ZONES_PGOFF - LAST_CPUPID_WIDTH) +#define KASAN_TAG_PGOFF (LAST_CPUPID_PGOFF - KASAN_TAG_WIDTH) /* * Define the bit shifts to access each section. For non-existent @@ -814,6 +815,7 @@ vm_fault_t finish_mkwrite_fault(struct vm_fault *vmf); #define NODES_PGSHIFT (NODES_PGOFF * (NODES_WIDTH != 0)) #define ZONES_PGSHIFT (ZONES_PGOFF * (ZONES_WIDTH != 0)) #define LAST_CPUPID_PGSHIFT (LAST_CPUPID_PGOFF * (LAST_CPUPID_WIDTH != 0)) +#define KASAN_TAG_PGSHIFT (KASAN_TAG_PGOFF * (KASAN_TAG_WIDTH != 0)) /* NODE:ZONE or SECTION:ZONE is used to ID a zone for the buddy allocator */ #ifdef NODE_NOT_IN_PAGE_FLAGS @@ -836,6 +838,7 @@ vm_fault_t finish_mkwrite_fault(struct vm_fault *vmf); #define NODES_MASK ((1UL << NODES_WIDTH) - 1) #define SECTIONS_MASK ((1UL << SECTIONS_WIDTH) - 1) #define LAST_CPUPID_MASK ((1UL << LAST_CPUPID_SHIFT) - 1) +#define KASAN_TAG_MASK ((1UL << KASAN_TAG_WIDTH) - 1) #define ZONEID_MASK ((1UL << ZONEID_SHIFT) - 1) static inline enum zone_type page_zonenum(const struct page *page) @@ -1101,6 +1104,32 @@ static inline bool cpupid_match_pid(struct task_struct *task, int cpupid) } #endif /* CONFIG_NUMA_BALANCING */ +#ifdef CONFIG_KASAN_SW_TAGS +static inline u8 page_kasan_tag(const struct page *page) +{ + return (page->flags >> KASAN_TAG_PGSHIFT) & KASAN_TAG_MASK; +} + +static inline void page_kasan_tag_set(struct page *page, u8 tag) +{ + page->flags &= ~(KASAN_TAG_MASK << KASAN_TAG_PGSHIFT); + page->flags |= (tag & KASAN_TAG_MASK) << KASAN_TAG_PGSHIFT; +} + +static inline void page_kasan_tag_reset(struct page *page) +{ + page_kasan_tag_set(page, 0xff); +} +#else +static inline u8 page_kasan_tag(const struct page *page) +{ + return 0xff; +} + +static inline void page_kasan_tag_set(struct page *page, u8 tag) { } +static inline void page_kasan_tag_reset(struct page *page) { } +#endif + static inline struct zone *page_zone(const struct page *page) { return &NODE_DATA(page_to_nid(page))->node_zones[page_zonenum(page)]; diff --git a/include/linux/page-flags-layout.h b/include/linux/page-flags-layout.h index 7ec86bf31ce4..1dda31825ec4 100644 --- a/include/linux/page-flags-layout.h +++ b/include/linux/page-flags-layout.h @@ -82,6 +82,16 @@ #define LAST_CPUPID_WIDTH 0 #endif +#ifdef CONFIG_KASAN_SW_TAGS +#define KASAN_TAG_WIDTH 8 +#if SECTIONS_WIDTH+NODES_WIDTH+ZONES_WIDTH+LAST_CPUPID_WIDTH+KASAN_TAG_WIDTH \ + > BITS_PER_LONG - NR_PAGEFLAGS +#error "KASAN: not enough bits in page flags for tag" +#endif +#else +#define KASAN_TAG_WIDTH 0 +#endif + /* * We are going to use the flags for the page to node mapping if its in * there. This includes the case where there is no node, so it is implicit. diff --git a/mm/cma.c b/mm/cma.c index 4cb76121a3ab..c7b39dd3b4f6 100644 --- a/mm/cma.c +++ b/mm/cma.c @@ -407,6 +407,7 @@ struct page *cma_alloc(struct cma *cma, size_t count, unsigned int align, unsigned long pfn = -1; unsigned long start = 0; unsigned long bitmap_maxno, bitmap_no, bitmap_count; + size_t i; struct page *page = NULL; int ret = -ENOMEM; @@ -466,6 +467,16 @@ struct page *cma_alloc(struct cma *cma, size_t count, unsigned int align, trace_cma_alloc(pfn, page, count, align); + /* + * CMA can allocate multiple page blocks, which results in different + * blocks being marked with different tags. Reset the tags to ignore + * those page blocks. + */ + if (page) { + for (i = 0; i < count; i++) + page_kasan_tag_reset(page + i); + } + if (ret && !no_warn) { pr_err("%s: alloc failed, req-size: %zu pages, ret: %d\n", __func__, count, ret); diff --git a/mm/kasan/common.c b/mm/kasan/common.c index 27f0cae336c9..195ca385cf7a 100644 --- a/mm/kasan/common.c +++ b/mm/kasan/common.c @@ -220,8 +220,15 @@ void kasan_unpoison_stack_above_sp_to(const void *watermark) void kasan_alloc_pages(struct page *page, unsigned int order) { + u8 tag; + unsigned long i; + if (unlikely(PageHighMem(page))) return; + + tag = random_tag(); + for (i = 0; i < (1 << order); i++) + page_kasan_tag_set(page + i, tag); kasan_unpoison_shadow(page_address(page), PAGE_SIZE << order); } @@ -319,6 +326,10 @@ struct kasan_free_meta *get_free_info(struct kmem_cache *cache, void kasan_poison_slab(struct page *page) { + unsigned long i; + + for (i = 0; i < (1 << compound_order(page)); i++) + page_kasan_tag_reset(page + i); kasan_poison_shadow(page_address(page), PAGE_SIZE << compound_order(page), KASAN_KMALLOC_REDZONE); @@ -517,7 +528,7 @@ void kasan_poison_kfree(void *ptr, unsigned long ip) page = virt_to_head_page(ptr); if (unlikely(!PageSlab(page))) { - if (reset_tag(ptr) != page_address(page)) { + if (ptr != page_address(page)) { kasan_report_invalid_free(ptr, ip); return; } @@ -530,7 +541,7 @@ void kasan_poison_kfree(void *ptr, unsigned long ip) void kasan_kfree_large(void *ptr, unsigned long ip) { - if (reset_tag(ptr) != page_address(virt_to_head_page(ptr))) + if (ptr != page_address(virt_to_head_page(ptr))) kasan_report_invalid_free(ptr, ip); /* The object will be poisoned by page_alloc. */ } diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 6847177dc4a1..5b2a1b6ef1be 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1183,6 +1183,7 @@ static void __meminit __init_single_page(struct page *page, unsigned long pfn, init_page_count(page); page_mapcount_reset(page); page_cpupid_reset_last(page); + page_kasan_tag_reset(page); INIT_LIST_HEAD(&page->lru); #ifdef WANT_PAGE_VIRTUAL diff --git a/mm/slab.c b/mm/slab.c index d2f827316dfc..d747433ecdbb 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -2357,7 +2357,7 @@ static void *alloc_slabmgmt(struct kmem_cache *cachep, void *freelist; void *addr = page_address(page); - page->s_mem = addr + colour_off; + page->s_mem = kasan_reset_tag(addr) + colour_off; page->active = 0; if (OBJFREELIST_SLAB(cachep))