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| author | Matthew Wilcox (Oracle) <willy@infradead.org> | 2022-01-11 02:15:27 +0300 |
|---|---|---|
| committer | Kees Cook <keescook@chromium.org> | 2022-04-13 22:15:50 +0300 |
| commit | 4e140f59d285c1ca1e5c81b4c13e27366865bd09 (patch) | |
| tree | 0e16718847cb02bacbe823ac5ba388619e46359f /include/linux/highmem-internal.h | |
| parent | a19944809fe9942e6a96292490717904d0690c21 (diff) | |
| download | linux-4e140f59d285c1ca1e5c81b4c13e27366865bd09.tar.xz | |
mm/usercopy: Check kmap addresses properly
If you are copying to an address in the kmap region, you may not copy
across a page boundary, no matter what the size of the underlying
allocation. You can't kmap() a slab page because slab pages always
come from low memory.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220110231530.665970-2-willy@infradead.org
Diffstat (limited to 'include/linux/highmem-internal.h')
| -rw-r--r-- | include/linux/highmem-internal.h | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/include/linux/highmem-internal.h b/include/linux/highmem-internal.h index a77be5630209..337bd9f32921 100644 --- a/include/linux/highmem-internal.h +++ b/include/linux/highmem-internal.h @@ -149,6 +149,11 @@ static inline void totalhigh_pages_add(long count) atomic_long_add(count, &_totalhigh_pages); } +static inline bool is_kmap_addr(const void *x) +{ + unsigned long addr = (unsigned long)x; + return addr >= PKMAP_ADDR(0) && addr < PKMAP_ADDR(LAST_PKMAP); +} #else /* CONFIG_HIGHMEM */ static inline struct page *kmap_to_page(void *addr) @@ -234,6 +239,11 @@ static inline void __kunmap_atomic(void *addr) static inline unsigned int nr_free_highpages(void) { return 0; } static inline unsigned long totalhigh_pages(void) { return 0UL; } +static inline bool is_kmap_addr(const void *x) +{ + return false; +} + #endif /* CONFIG_HIGHMEM */ /* |