Affected: Linux

In the Linux kernel, the following vulnerability has been resolved:

ntfs: fix kmap_local_page() usage in compress

Several compressed I/O paths discard the address returned by kmap_local_page() and later access or unmap the page using page_address(). This is invalid for highmem pages, and local mappings must also be unmapped using the address returned by kmap_local_page().

Map each destination page in ntfs_decompress() only while producing the current sub-block. Use memcpy_from_page(), memcpy_to_page(), and memzero_page() for the other page accesses. Remove unnecessary local mappings from ntfs_write_cb(), where pages are accessed through the vmap() mapping.