From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f54.google.com (mail-pa0-f54.google.com [209.85.220.54]) by kanga.kvack.org (Postfix) with ESMTP id C12286B003A for ; Wed, 10 Sep 2014 10:38:33 -0400 (EDT) Received: by mail-pa0-f54.google.com with SMTP id lj1so8615084pab.41 for ; Wed, 10 Sep 2014 07:38:33 -0700 (PDT) Received: from mailout1.w1.samsung.com (mailout1.w1.samsung.com. [210.118.77.11]) by mx.google.com with ESMTPS id xl6si3372005pab.225.2014.09.10.07.38.32 for (version=TLSv1 cipher=RC4-MD5 bits=128/128); Wed, 10 Sep 2014 07:38:32 -0700 (PDT) Received: from eucpsbgm1.samsung.com (unknown [203.254.199.244]) by mailout1.w1.samsung.com (Oracle Communications Messaging Server 7u4-24.01(7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTP id <0NBO00DCMWSZ2P60@mailout1.w1.samsung.com> for linux-mm@kvack.org; Wed, 10 Sep 2014 15:41:23 +0100 (BST) From: Andrey Ryabinin Subject: [RFC/PATCH v2 03/10] mm: page_alloc: add kasan hooks on alloc and free pathes Date: Wed, 10 Sep 2014 18:31:20 +0400 Message-id: <1410359487-31938-4-git-send-email-a.ryabinin@samsung.com> In-reply-to: <1410359487-31938-1-git-send-email-a.ryabinin@samsung.com> References: <1404905415-9046-1-git-send-email-a.ryabinin@samsung.com> <1410359487-31938-1-git-send-email-a.ryabinin@samsung.com> Sender: owner-linux-mm@kvack.org List-ID: To: linux-kernel@vger.kernel.org Cc: Andrey Ryabinin , Dmitry Vyukov , Konstantin Serebryany , Dmitry Chernenkov , Andrey Konovalov , Yuri Gribov , Konstantin Khlebnikov , Sasha Levin , Christoph Lameter , Joonsoo Kim , Andrew Morton , Dave Hansen , Andi Kleen , Vegard Nossum , "H. Peter Anvin" , x86@kernel.org, linux-mm@kvack.org Add kernel address sanitizer hooks to mark allocated page's addresses as accessible in corresponding shadow region. Mark freed pages as unaccessible. 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 f957ee9..c5ae971 100644 --- a/include/linux/kasan.h +++ b/include/linux/kasan.h @@ -31,6 +31,9 @@ static inline void kasan_disable_local(void) void kasan_unpoison_shadow(const void *address, size_t size); void kasan_map_shadow(void); +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) {} @@ -40,6 +43,9 @@ static inline void kasan_disable_local(void) {} static inline void kasan_map_shadow(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 7d9d92e..a8c5d6d 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -16,6 +16,7 @@ #include #include #include +#include #include "internal.h" #ifdef CONFIG_COMPACTION @@ -59,6 +60,7 @@ 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 65f8145..ed4e925 100644 --- a/mm/kasan/kasan.c +++ b/mm/kasan/kasan.c @@ -109,6 +109,20 @@ static __always_inline void check_memory_region(unsigned long addr, kasan_report_error(&info); } +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 2ea2ed7..227e9c6 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 3bfc8b6..94d79e7 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 3935c9a..63c55c9 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -61,6 +61,7 @@ #include #include #include +#include #include #include @@ -753,6 +754,7 @@ 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; @@ -932,6 +934,7 @@ 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); -- 1.8.5.5 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. 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