From patchwork Tue Nov 6 17:30:34 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrey Konovalov X-Patchwork-Id: 10671061 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 6B5F313BF for ; Tue, 6 Nov 2018 17:36:35 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 512EA2ACE5 for ; Tue, 6 Nov 2018 17:36:35 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 42B5B2ACD2; Tue, 6 Nov 2018 17:36:35 +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=-3.6 required=2.0 tests=BAYES_00,DKIM_ADSP_CUSTOM_MED, DKIM_SIGNED,DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_LOW autolearn=unavailable version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 7CDC62ACC9 for ; Tue, 6 Nov 2018 17:36:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=HZ8uNEz9fH73e0ckByC/6UktEgB3KaPLviXWFzy6Ygw=; b=p5Y+SRstoE1KNL XGgIjqQDARiVmnQjtYrYcqsvuUg535T/IhqcSVZX/ZNqdfCELi1Q7v3yg8GxcYV3JdydD5ML2ve7o dZv5aJPKX3aA5PucGL3Iwp3o9Od45J4QLaoIclJMntyMJAxiKT0lCdoH0zX63DvqOxx0eoTf7y9y5 t3czfszUjvuSrFrQ5qkUapoKV2Kx9IfO76h0SpERr7KxuyrP2QGyWf5SDlRhxvZn08oUV5T8LUXdK gaI27D+Aw4+n9HJWs6y8n2m/TDRi/FLcxfuxK/atSo2YZnA5CMaOAELXWr9GNmUMU6p5rwPZEpAN6 /ODKSrMdfluw+q4UxMYA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gK5HA-00037M-9R; Tue, 06 Nov 2018 17:36:28 +0000 Received: from mail-wm1-x343.google.com ([2a00:1450:4864:20::343]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1gK5CA-0005Rm-I9 for linux-arm-kernel@lists.infradead.org; Tue, 06 Nov 2018 17:31:22 +0000 Received: by mail-wm1-x343.google.com with SMTP id t15-v6so5131563wmt.0 for ; Tue, 06 Nov 2018 09:31:14 -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=DBi4b5mp1uQMIpBdyajagHQ1WOtpTOcwif2rDCgCV7o=; b=r71XCKY5JOOhJklIvp8L6g7T6Eiq+KqLVewDKvtcuMcJn7F58q3B/1HqHW5s5zHnCf ahWNhVFjUWTqjyCFVWO7NST8b8ilf2mNr3EnsBfwnpzFOMPC8K/VsiuCA7mCKIVH6rZi Kv9jKkcNyY4dcCoyQeCXwZ0MTeWgFpGjR4vsNgw2tSW8/DwQpdB6dc3uEGfrp2RsyJ3V mbdkQLj9q8BUfDSkX8WB3YXl+ZaW7Ya4PUEcZnfDUg4lEPzVjW9/sUGCuhDOScgQhnkq BggKOtjBB+5pgCPcFlTfdfpcjAjLUsuOiTsX2NxiUY7mwGveBxKjwQIK7J5NyOVNi+9g Gi2w== 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=DBi4b5mp1uQMIpBdyajagHQ1WOtpTOcwif2rDCgCV7o=; b=eUneXbNFIu1LG16ublJW68N/L28QDpUUe+fweNxMfBKq8egWnBKI8VNeESsldN1AvG 9t87nssRjz8xAmFN97VG4XiC5WaRYd1cxnKgYBLkFGzWucxemc8FQxNwtTuXMOZ+Cox1 dVh0FcMGWYHx/AUgpmTCN3p2UYZFVh9wBsCC7FFhGo7hAD2KU0bWyFgrOExI3pPdKPoa TxJh+eQucXZ0qL6XY0PWkq8ddSwtPbvOek4ioteYU/l9YgzK4J9Acy9UCXPTCI9rmTv3 09mZlgcSq1158d2kHw15dNEUnmtwwdgpe96mcobXXbzRWm0EQH5SMIqjJmnh9imqxD/E XMfA== X-Gm-Message-State: AGRZ1gKdCPo06XvsQcG0NmtSx5VlV2N1+DVWCcKJvl3EPhHLAPL+7pbA N6qDa0mfWCvPTRDNlPhyLrgBQg== X-Google-Smtp-Source: AJdET5cULYwcOHC8ORe5fmEH1QOsk6mtjsMrg71esstmiY2xGlxcGrQZRwBGvq0FAc6Vam1oXhmMCw== X-Received: by 2002:a7b:c10e:: with SMTP id w14-v6mr2775079wmi.20.1541525473251; Tue, 06 Nov 2018 09:31:13 -0800 (PST) Received: from andreyknvl0.muc.corp.google.com ([2a00:79e0:15:10:84be:a42a:826d:c530]) by smtp.gmail.com with ESMTPSA id z17-v6sm16328416wrm.65.2018.11.06.09.31.11 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 06 Nov 2018 09:31:12 -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 Subject: [PATCH v10 19/22] kasan, mm, arm64: tag non slab memory allocated via pagealloc Date: Tue, 6 Nov 2018 18:30:34 +0100 Message-Id: <34f2d93fec145f7903944fca2e99c4a435eb1192.1541525354.git.andreyknvl@google.com> X-Mailer: git-send-email 2.19.1.930.g4563a0d9d0-goog In-Reply-To: References: MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20181106_093118_683792_4395D9BF X-CRM114-Status: GOOD ( 25.31 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Vishwath Mohan , Chintan Pandya , Jacob Bramley , Jann Horn , Ruben Ayrapetyan , Andrey Konovalov , Lee Smith , Kostya Serebryany , Mark Brand , Ramana Radhakrishnan , Evgeniy Stepanov Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.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 | 9 ++++++++- 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, 73 insertions(+), 4 deletions(-) diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h index 3226a0218b0b..b7108161732e 100644 --- a/arch/arm64/include/asm/memory.h +++ b/arch/arm64/include/asm/memory.h @@ -98,6 +98,7 @@ KASAN_TAG_SHIFTED(tag)) #define KASAN_RESET_TAG(addr) KASAN_SET_TAG(addr, 0xff) #else +#define KASAN_SET_TAG(addr, tag) addr #define KASAN_RESET_TAG(addr) addr #endif @@ -309,7 +310,13 @@ 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 = KASAN_SET_TAG(__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 fcf9cc9d535f..03c37e25ee10 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 a919ba5cb3c8..ed6dc8f18c01 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))