[PATCH V2.1] mm/highmem: Add VM_BUG_ON() to mem*_page() calls
From: <hidden>
Date: 2021-02-10 17:50:41
Also in:
lkml
Subsystem:
memory management - core, the rest · Maintainers:
Andrew Morton, David Hildenbrand, Linus Torvalds
From: Ira Weiny <redacted> 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.[1][2] [1] https://lore.kernel.org/lkml/20201210053502.GS1563847@iweiny-DESK2.sc.intel.com/ (local) [2] https://lore.kernel.org/lkml/20210209110931.00f00e47d9a0529fcee2ff01@linux-foundation.org/ (local) Suggested-by: Matthew Wilcox <willy@infradead.org> Suggested-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ira Weiny <redacted> --- Changes from V2: Actually, really do VM_BUG_ON... <sigh> Clean up commit message --- include/linux/highmem.h | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/include/linux/highmem.h b/include/linux/highmem.h
index 0b5d89621cb9..44170f312ae7 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); + VM_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); + VM_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); + VM_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); + VM_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); + VM_BUG_ON(offset + len > PAGE_SIZE); memcpy(to + offset, from, len); kunmap_local(to); }
--
2.28.0.rc0.12.gb6a658bd00c9