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From: ira.weiny@intel.com
To: Andrew Morton <akpm@linux-foundation.org>,
	David Sterba <dsterba@suse.cz>
Cc: Ira Weiny <ira.weiny@intel.com>,
	Christoph Hellwig <hch@infradead.org>,
	Matthew Wilcox <willy@infradead.org>,
	clm@fb.com, josef@toxicpanda.com, linux-kernel@vger.kernel.org,
	linux-fsdevel@vger.kernel.org
Subject: [PATCH V2 4/8] mm/highmem: Add VM_BUG_ON() to mem*_page() calls
Date: Tue,  9 Feb 2021 22:22:17 -0800	[thread overview]
Message-ID: <20210210062221.3023586-5-ira.weiny@intel.com> (raw)
In-Reply-To: <20210210062221.3023586-1-ira.weiny@intel.com>

From: Ira Weiny <ira.weiny@intel.com>

Add VM_BUG_ON bounds checks to ensure the newly lifted and created page
memory operations do not result in corrupted data in neighbor pages and
to make them consistent with zero_user().[1][2]

[1] https://lore.kernel.org/lkml/20201210053502.GS1563847@iweiny-DESK2.sc.intel.com/
[2] https://lore.kernel.org/lkml/20210209110931.00f00e47d9a0529fcee2ff01@linux-foundation.org/

Cc: Christoph Hellwig <hch@infradead.org>
Suggested-by: Matthew Wilcox <willy@infradead.org>
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>

---
New for V2
---
 include/linux/highmem.h | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/include/linux/highmem.h b/include/linux/highmem.h
index 0b5d89621cb9..520bbc67e67f 100644
--- a/include/linux/highmem.h
+++ b/include/linux/highmem.h
@@ -283,6 +283,7 @@ static inline void memcpy_page(struct page *dst_page, size_t dst_off,
 	char *dst = kmap_local_page(dst_page);
 	char *src = kmap_local_page(src_page);
 
+	BUG_ON(dst_off + len > PAGE_SIZE || src_off + len > PAGE_SIZE);
 	memcpy(dst + dst_off, src + src_off, len);
 	kunmap_local(src);
 	kunmap_local(dst);
@@ -295,6 +296,7 @@ static inline void memmove_page(struct page *dst_page, size_t dst_off,
 	char *dst = kmap_local_page(dst_page);
 	char *src = kmap_local_page(src_page);
 
+	BUG_ON(dst_off + len > PAGE_SIZE || src_off + len > PAGE_SIZE);
 	memmove(dst + dst_off, src + src_off, len);
 	kunmap_local(src);
 	kunmap_local(dst);
@@ -305,6 +307,7 @@ static inline void memset_page(struct page *page, size_t offset, int val,
 {
 	char *addr = kmap_local_page(page);
 
+	BUG_ON(offset + len > PAGE_SIZE);
 	memset(addr + offset, val, len);
 	kunmap_local(addr);
 }
@@ -314,6 +317,7 @@ static inline void memcpy_from_page(char *to, struct page *page,
 {
 	char *from = kmap_local_page(page);
 
+	BUG_ON(offset + len > PAGE_SIZE);
 	memcpy(to, from + offset, len);
 	kunmap_local(from);
 }
@@ -323,6 +327,7 @@ static inline void memcpy_to_page(struct page *page, size_t offset,
 {
 	char *to = kmap_local_page(page);
 
+	BUG_ON(offset + len > PAGE_SIZE);
 	memcpy(to + offset, from, len);
 	kunmap_local(to);
 }
-- 
2.28.0.rc0.12.gb6a658bd00c9


  parent reply	other threads:[~2021-02-10  6:25 UTC|newest]

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-02-10  6:22 [PATCH V2 0/8] btrfs: convert kmaps to core page calls ira.weiny
2021-02-10  6:22 ` [PATCH V2 1/8] mm/highmem: Lift memcpy_[to|from]_page to core ira.weiny
2021-02-10  6:33   ` Chaitanya Kulkarni
2021-02-10 12:53   ` Christoph Hellwig
2021-02-10  6:22 ` [PATCH V2 2/8] mm/highmem: Convert memcpy_[to|from]_page() to kmap_local_page() ira.weiny
2021-02-10  6:37   ` Chaitanya Kulkarni
2021-02-10 12:54   ` Christoph Hellwig
2021-02-10  6:22 ` [PATCH V2 3/8] mm/highmem: Introduce memcpy_page(), memmove_page(), and memset_page() ira.weiny
2021-02-10  6:46   ` Chaitanya Kulkarni
2021-02-10 12:54   ` Christoph Hellwig
2021-02-10  6:22 ` ira.weiny [this message]
2021-02-10  6:57   ` [PATCH V2 4/8] mm/highmem: Add VM_BUG_ON() to mem*_page() calls Chaitanya Kulkarni
2021-02-10 16:31     ` Ira Weiny
2021-02-10 12:55   ` Christoph Hellwig
2021-02-10 16:29     ` Ira Weiny
2021-02-10 16:41       ` Christoph Hellwig
2021-02-10 17:04         ` Ira Weiny
2021-02-10 18:56       ` Matthew Wilcox
2021-02-10 21:22         ` Ira Weiny
2021-02-11 18:52           ` David Sterba
2021-02-10 17:49   ` [PATCH V2.1] " ira.weiny
2021-02-10  6:22 ` [PATCH V2 5/8] iov_iter: Remove memzero_page() in favor of zero_user() ira.weiny
2021-02-10 12:55   ` Christoph Hellwig
2021-02-10  6:22 ` [PATCH V2 6/8] btrfs: use memcpy_[to|from]_page() and kmap_local_page() ira.weiny
2021-02-10 12:56   ` Christoph Hellwig
2021-02-10  6:22 ` [PATCH V2 7/8] btrfs: use copy_highpage() instead of 2 kmaps() ira.weiny
2021-02-10 12:56   ` Christoph Hellwig
2021-02-10  6:22 ` [PATCH V2 8/8] btrfs: convert to zero_user() ira.weiny
2021-02-10 12:57   ` Christoph Hellwig
2021-02-11 19:38 ` [PATCH V2 0/8] btrfs: convert kmaps to core page calls David Sterba
2021-02-11 21:32   ` Ira Weiny

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