Messages in this thread Patch in this message | | | From | "Fabio M. De Francesco" <> | Subject | [PATCH] mm/highmem: VM_BUG_ON() if offset + len > PAGE_SIZE | Date | Tue, 26 Apr 2022 21:30:20 +0200 |
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Add VM_BUG_ON() bounds checking to make sure that, if "offset + len> PAGE_SIZE", memset() does not corrupt data in adjacent pages.
Cc: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com> --- include/linux/highmem.h | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/include/linux/highmem.h b/include/linux/highmem.h index 6b2d59e025c5..d54dbaae9a5e 100644 --- a/include/linux/highmem.h +++ b/include/linux/highmem.h @@ -380,6 +380,8 @@ static inline void memcpy_to_page(struct page *page, size_t offset, static inline void memzero_page(struct page *page, size_t offset, size_t len) { char *addr = kmap_local_page(page); + + VM_BUG_ON(offset + len > PAGE_SIZE); memset(addr + offset, 0, len); flush_dcache_page(page); kunmap_local(addr); -- 2.34.1
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