diff options
| author | Fabio M. De Francesco <fmdefrancesco@gmail.com> | 2022-05-09 18:20:51 -0700 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2022-05-13 07:20:06 -0700 |
| commit | f38adfef7e6bfe681d6602b6668be31fe1310ed0 (patch) | |
| tree | bbc24e92abab0dddbee031911eeb7d3705f788ae /include/linux/highmem.h | |
| parent | 3c81b3bb0a33e2b555edb8d7eb99a7ae4f17d8bb (diff) | |
| download | lwn-f38adfef7e6bfe681d6602b6668be31fe1310ed0.tar.gz lwn-f38adfef7e6bfe681d6602b6668be31fe1310ed0.zip | |
mm/highmem: VM_BUG_ON() if offset + len > PAGE_SIZE
Add VM_BUG_ON() bounds checking to make sure that, if "offset + len>
PAGE_SIZE", memset() does not corrupt data in adjacent pages.
Mainly to match all the similar functions in highmem.h.
Link: https://lkml.kernel.org/r/20220426193020.8710-1-fmdefrancesco@gmail.com
Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Peter Collingbourne <pcc@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'include/linux/highmem.h')
| -rw-r--r-- | include/linux/highmem.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/highmem.h b/include/linux/highmem.h index 39bb9b47fa9c..67720bfd6ade 100644 --- a/include/linux/highmem.h +++ b/include/linux/highmem.h @@ -358,6 +358,8 @@ 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); |