From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f179.google.com (mail-pd0-f179.google.com [209.85.192.179]) by kanga.kvack.org (Postfix) with ESMTP id 2815B6B00CB for ; Mon, 24 Nov 2014 13:02:46 -0500 (EST) Received: by mail-pd0-f179.google.com with SMTP id w10so10142458pde.24 for ; Mon, 24 Nov 2014 10:02:45 -0800 (PST) Received: from mailout4.w1.samsung.com (mailout4.w1.samsung.com. [210.118.77.14]) by mx.google.com with ESMTPS id kj8si22569609pdb.175.2014.11.24.10.02.43 for (version=TLSv1 cipher=RC4-MD5 bits=128/128); Mon, 24 Nov 2014 10:02:44 -0800 (PST) Received: from eucpsbgm1.samsung.com (unknown [203.254.199.244]) by mailout4.w1.samsung.com (Oracle Communications Messaging Server 7u4-24.01(7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTP id <0NFK001M728ZDM00@mailout4.w1.samsung.com> for linux-mm@kvack.org; Mon, 24 Nov 2014 18:05:23 +0000 (GMT) From: Andrey Ryabinin Subject: [PATCH v7 04/12] mm: page_alloc: add kasan hooks on alloc and free paths Date: Mon, 24 Nov 2014 21:02:17 +0300 Message-id: <1416852146-9781-5-git-send-email-a.ryabinin@samsung.com> In-reply-to: <1416852146-9781-1-git-send-email-a.ryabinin@samsung.com> References: <1404905415-9046-1-git-send-email-a.ryabinin@samsung.com> <1416852146-9781-1-git-send-email-a.ryabinin@samsung.com> Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: Andrey Ryabinin , Dmitry Vyukov , Konstantin Serebryany , Dmitry Chernenkov , Andrey Konovalov , Yuri Gribov , Konstantin Khlebnikov , Sasha Levin , Christoph Lameter , Joonsoo Kim , Dave Hansen , Andi Kleen , Vegard Nossum , "H. Peter Anvin" , Dave Jones , x86@kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Add kernel address sanitizer hooks to mark allocated page's addresses as accessible in corresponding shadow region. Mark freed pages as inaccessible. Signed-off-by: Andrey Ryabinin --- include/linux/kasan.h | 6 ++++++ mm/compaction.c | 2 ++ mm/kasan/kasan.c | 14 ++++++++++++++ mm/kasan/kasan.h | 1 + mm/kasan/report.c | 7 +++++++ mm/page_alloc.c | 3 +++ 6 files changed, 33 insertions(+) diff --git a/include/linux/kasan.h b/include/linux/kasan.h index 01c99fe..9714fba 100644 --- a/include/linux/kasan.h +++ b/include/linux/kasan.h @@ -30,6 +30,9 @@ static inline void kasan_disable_local(void) void kasan_unpoison_shadow(const void *address, size_t size); +void kasan_alloc_pages(struct page *page, unsigned int order); +void kasan_free_pages(struct page *page, unsigned int order); + #else /* CONFIG_KASAN */ static inline void kasan_unpoison_shadow(const void *address, size_t size) {} @@ -37,6 +40,9 @@ static inline void kasan_unpoison_shadow(const void *address, size_t size) {} static inline void kasan_enable_local(void) {} static inline void kasan_disable_local(void) {} +static inline void kasan_alloc_pages(struct page *page, unsigned int order) {} +static inline void kasan_free_pages(struct page *page, unsigned int order) {} + #endif /* CONFIG_KASAN */ #endif /* LINUX_KASAN_H */ diff --git a/mm/compaction.c b/mm/compaction.c index a857225..a5c8e84 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -16,6 +16,7 @@ #include #include #include +#include #include "internal.h" #ifdef CONFIG_COMPACTION @@ -61,6 +62,7 @@ static void map_pages(struct list_head *list) list_for_each_entry(page, list, lru) { arch_alloc_page(page, 0); kernel_map_pages(page, 1, 1); + kasan_alloc_pages(page, 0); } } diff --git a/mm/kasan/kasan.c b/mm/kasan/kasan.c index f77be01..b336073 100644 --- a/mm/kasan/kasan.c +++ b/mm/kasan/kasan.c @@ -247,6 +247,20 @@ static __always_inline void check_memory_region(unsigned long addr, kasan_report(addr, size, write); } +void kasan_alloc_pages(struct page *page, unsigned int order) +{ + if (likely(!PageHighMem(page))) + kasan_unpoison_shadow(page_address(page), PAGE_SIZE << order); +} + +void kasan_free_pages(struct page *page, unsigned int order) +{ + if (likely(!PageHighMem(page))) + kasan_poison_shadow(page_address(page), + PAGE_SIZE << order, + KASAN_FREE_PAGE); +} + void __asan_load1(unsigned long addr) { check_memory_region(addr, 1, false); diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h index 6da1d78..2a6a961 100644 --- a/mm/kasan/kasan.h +++ b/mm/kasan/kasan.h @@ -6,6 +6,7 @@ #define KASAN_SHADOW_SCALE_SIZE (1UL << KASAN_SHADOW_SCALE_SHIFT) #define KASAN_SHADOW_MASK (KASAN_SHADOW_SCALE_SIZE - 1) +#define KASAN_FREE_PAGE 0xFF /* page was freed */ #define KASAN_SHADOW_GAP 0xF9 /* address belongs to shadow memory */ struct access_info { diff --git a/mm/kasan/report.c b/mm/kasan/report.c index 56a2089..8ac3b6b 100644 --- a/mm/kasan/report.c +++ b/mm/kasan/report.c @@ -57,6 +57,9 @@ static void print_error_description(struct access_info *info) case 0 ... KASAN_SHADOW_SCALE_SIZE - 1: bug_type = "out of bounds access"; break; + case KASAN_FREE_PAGE: + bug_type = "use after free"; + break; case KASAN_SHADOW_GAP: bug_type = "wild memory access"; break; @@ -78,6 +81,10 @@ static void print_address_description(struct access_info *info) page = virt_to_head_page((void *)info->access_addr); switch (shadow_val) { + case KASAN_FREE_PAGE: + dump_page(page, "kasan error"); + dump_stack(); + break; case KASAN_SHADOW_GAP: pr_err("No metainfo is available for this access.\n"); dump_stack(); diff --git a/mm/page_alloc.c b/mm/page_alloc.c index b0e6eab..3829589 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -58,6 +58,7 @@ #include #include #include +#include #include #include @@ -758,6 +759,7 @@ static bool free_pages_prepare(struct page *page, unsigned int order) trace_mm_page_free(page, order); kmemcheck_free_shadow(page, order); + kasan_free_pages(page, order); if (PageAnon(page)) page->mapping = NULL; @@ -940,6 +942,7 @@ static int prep_new_page(struct page *page, unsigned int order, gfp_t gfp_flags) arch_alloc_page(page, order); kernel_map_pages(page, 1 << order, 1); + kasan_alloc_pages(page, order); if (gfp_flags & __GFP_ZERO) prep_zero_page(page, order, gfp_flags); -- 2.1.3 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. 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