From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: ARC-Seal: i=1; a=rsa-sha256; t=1525800080; cv=none; d=google.com; s=arc-20160816; b=Og8aEyNAixxf2xJgRVZeVZWnoHofbSfHSTbRGaYxwBjWAovuFBm6Q23alIUOqRdIZH aBEWVtG2z+yWCEN6Z6uYuTq2RMKNjFaRHCzM/PxHf7sygdfER0AhNyS8jJ3WREgT52yc AO9SjFR+jEYtVJwpHGpjZ4W0AFCbiWptzbdCgdaAMi8+47/PlTuRfeEJrQ1I395gj/fB a0U9RN8txVX7mn3xKz0VQpFYlGphgYZz6VUfyltBCtXcrq83DXO+fkupiANwEmIhOPOK hYx25oiiRQFBGqACAQXPLy2ZImuhtcqIdNS70cgaAufeSTimSsunprAkgZfVjKEjBGcy kZXw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=references:in-reply-to:references:in-reply-to:message-id:date :subject:cc:to:from:dkim-signature:arc-authentication-results; bh=IFwqCsYeJvS9ff1sRi33loEFnxudx8Y7zwbp4h1TJhc=; b=k7Dn0nl8uhenskLJVTpK7DDStUlOorXCkiAQEuHYneLuVG7FWyalRQXCJgHin/77t2 mnrniDmoYlztMqyZWmtCQ6cCkZSYOvLpY/bIiVW4Xv+XHocFd0EpsYCZDyHh7y8K/s2m ooDS10D8TiAKyB8fGFFfiK05q7iHWQbZAEBHJ+pMc3aqMfcOzgRhBvQyBs0pAqkNAlUz u+cIrgE2z9gWoEoSC1KqO7/QTFuJo6S9tMLWsQX28fXvRmf0DxRhDSPPsh6ZelFJm63F UtWS83q8J4Zg/T8e9WL/DL3NwQxnhmW6Z99DZI4RhrkCc+KleOhqClj11e/LVUa6EfJu 7k1w== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@google.com header.s=20161025 header.b=ImakKwvs; spf=pass (google.com: domain of andreyknvl@google.com designates 209.85.220.65 as permitted sender) smtp.mailfrom=andreyknvl@google.com; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=google.com Authentication-Results: mx.google.com; dkim=pass header.i=@google.com header.s=20161025 header.b=ImakKwvs; spf=pass (google.com: domain of andreyknvl@google.com designates 209.85.220.65 as permitted sender) smtp.mailfrom=andreyknvl@google.com; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=google.com X-Google-Smtp-Source: AB8JxZpS9fs6QZsV1CqH8H8ummhsjhlQo38urUnCzGDtigeOD05VINaZv84Zs4Pf+D3CUHRCY2mhRw== From: Andrey Konovalov To: Andrey Ryabinin , Alexander Potapenko , Dmitry Vyukov , Jonathan Corbet , Catalin Marinas , Will Deacon , Christopher Li , Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , Andrew Morton , Masahiro Yamada , Michal Marek , Andrey Konovalov , Mark Rutland , Nick Desaulniers , Yury Norov , Marc Zyngier , Kristina Martsenko , Suzuki K Poulose , Punit Agrawal , Dave Martin , Ard Biesheuvel , James Morse , Michael Weiser , Julien Thierry , Tyler Baicar , "Eric W . Biederman" , Thomas Gleixner , Ingo Molnar , Kees Cook , Sandipan Das , David Woodhouse , Paul Lawrence , Herbert Xu , Josh Poimboeuf , Geert Uytterhoeven , Tom Lendacky , Arnd Bergmann , Dan Williams , Michal Hocko , Jan Kara , Ross Zwisler , =?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?= , Matthew Wilcox , "Kirill A . Shutemov" , Souptick Joarder , Hugh Dickins , Davidlohr Bueso , Greg Kroah-Hartman , Philippe Ombredanne , Kate Stewart , Laura Abbott , Boris Brezillon , Vlastimil Babka , Pintu Agarwal , Doug Berger , Anshuman Khandual , Mike Rapoport , Mel Gorman , Pavel Tatashin , Tetsuo Handa , 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 , Kees Cook , Jann Horn , Mark Brand , Chintan Pandya Subject: [PATCH v1 05/16] khwasan: initialize shadow to 0xff Date: Tue, 8 May 2018 19:20:51 +0200 Message-Id: <7c1197bce60a0d18c178ab5f025c438afa84be21.1525798754.git.andreyknvl@google.com> X-Mailer: git-send-email 2.17.0.441.gb46fe60e1d-goog In-Reply-To: References: In-Reply-To: References: X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1599917345072629108?= X-GMAIL-MSGID: =?utf-8?q?1599917345072629108?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: A KHWASAN shadow memory cell contains a memory tag, that corresponds to the tag in the top byte of the pointer, that points to that memory. The native top byte value of kernel pointers is 0xff, so with KHWASAN we need to initialize shadow memory to 0xff. This commit does that. Signed-off-by: Andrey Konovalov --- arch/arm64/mm/kasan_init.c | 16 ++++++++++++++-- include/linux/kasan.h | 8 ++++++++ mm/kasan/common.c | 3 ++- 3 files changed, 24 insertions(+), 3 deletions(-) diff --git a/arch/arm64/mm/kasan_init.c b/arch/arm64/mm/kasan_init.c index 12145874c02b..7a31e8ccbad2 100644 --- a/arch/arm64/mm/kasan_init.c +++ b/arch/arm64/mm/kasan_init.c @@ -44,6 +44,15 @@ static phys_addr_t __init kasan_alloc_zeroed_page(int node) return __pa(p); } +static phys_addr_t __init kasan_alloc_raw_page(int node) +{ + void *p = memblock_virt_alloc_try_nid_raw(PAGE_SIZE, PAGE_SIZE, + __pa(MAX_DMA_ADDRESS), + MEMBLOCK_ALLOC_ACCESSIBLE, + node); + return __pa(p); +} + static pte_t *__init kasan_pte_offset(pmd_t *pmdp, unsigned long addr, int node, bool early) { @@ -89,7 +98,9 @@ static void __init kasan_pte_populate(pmd_t *pmdp, unsigned long addr, do { phys_addr_t page_phys = early ? __pa_symbol(kasan_zero_page) - : kasan_alloc_zeroed_page(node); + : kasan_alloc_raw_page(node); + if (!early) + memset(__va(page_phys), KASAN_SHADOW_INIT, PAGE_SIZE); next = addr + PAGE_SIZE; set_pte(ptep, pfn_pte(__phys_to_pfn(page_phys), PAGE_KERNEL)); } while (ptep++, addr = next, addr != end && pte_none(READ_ONCE(*ptep))); @@ -139,6 +150,7 @@ asmlinkage void __init kasan_early_init(void) KASAN_SHADOW_END - (1UL << (64 - KASAN_SHADOW_SCALE_SHIFT))); BUILD_BUG_ON(!IS_ALIGNED(KASAN_SHADOW_START, PGDIR_SIZE)); BUILD_BUG_ON(!IS_ALIGNED(KASAN_SHADOW_END, PGDIR_SIZE)); + kasan_pgd_populate(KASAN_SHADOW_START, KASAN_SHADOW_END, NUMA_NO_NODE, true); } @@ -235,7 +247,7 @@ void __init kasan_init(void) set_pte(&kasan_zero_pte[i], pfn_pte(sym_to_pfn(kasan_zero_page), PAGE_KERNEL_RO)); - memset(kasan_zero_page, 0, PAGE_SIZE); + memset(kasan_zero_page, KASAN_SHADOW_INIT, PAGE_SIZE); cpu_replace_ttbr1(lm_alias(swapper_pg_dir)); /* At this point kasan is fully initialized. Enable error messages */ diff --git a/include/linux/kasan.h b/include/linux/kasan.h index 6608aa9b35ac..336385baf926 100644 --- a/include/linux/kasan.h +++ b/include/linux/kasan.h @@ -139,6 +139,8 @@ static inline size_t kasan_metadata_size(struct kmem_cache *cache) { return 0; } #ifdef CONFIG_KASAN_GENERIC +#define KASAN_SHADOW_INIT 0 + void kasan_cache_shrink(struct kmem_cache *cache); void kasan_cache_shutdown(struct kmem_cache *cache); @@ -149,4 +151,10 @@ static inline void kasan_cache_shutdown(struct kmem_cache *cache) {} #endif /* CONFIG_KASAN_GENERIC */ +#ifdef CONFIG_KASAN_HW + +#define KASAN_SHADOW_INIT 0xFF + +#endif /* CONFIG_KASAN_HW */ + #endif /* LINUX_KASAN_H */ diff --git a/mm/kasan/common.c b/mm/kasan/common.c index ebb48415e4cf..0c1159feaf5e 100644 --- a/mm/kasan/common.c +++ b/mm/kasan/common.c @@ -454,11 +454,12 @@ int kasan_module_alloc(void *addr, size_t size) ret = __vmalloc_node_range(shadow_size, 1, shadow_start, shadow_start + shadow_size, - GFP_KERNEL | __GFP_ZERO, + GFP_KERNEL, PAGE_KERNEL, VM_NO_GUARD, NUMA_NO_NODE, __builtin_return_address(0)); if (ret) { + __memset(ret, KASAN_SHADOW_INIT, shadow_size); find_vm_area(addr)->flags |= VM_KASAN; kmemleak_ignore(ret); return 0; -- 2.17.0.441.gb46fe60e1d-goog