diff options
Diffstat (limited to 'mm/usercopy.c')
| -rw-r--r-- | mm/usercopy.c | 26 |
1 files changed, 12 insertions, 14 deletions
diff --git a/mm/usercopy.c b/mm/usercopy.c index baeacc735b83..4e1da708699b 100644 --- a/mm/usercopy.c +++ b/mm/usercopy.c @@ -161,29 +161,27 @@ static inline void check_bogus_address(const unsigned long ptr, unsigned long n, static inline void check_heap_object(const void *ptr, unsigned long n, bool to_user) { + uintptr_t addr = (uintptr_t)ptr; + unsigned long offset; struct folio *folio; if (is_kmap_addr(ptr)) { - unsigned long page_end = (unsigned long)ptr | (PAGE_SIZE - 1); - - if ((unsigned long)ptr + n - 1 > page_end) - usercopy_abort("kmap", NULL, to_user, - offset_in_page(ptr), n); + offset = offset_in_page(ptr); + if (n > PAGE_SIZE - offset) + usercopy_abort("kmap", NULL, to_user, offset, n); return; } if (is_vmalloc_addr(ptr)) { - struct vm_struct *area = find_vm_area(ptr); - unsigned long offset; + struct vmap_area *area = find_vmap_area(addr); - if (!area) { + if (!area) usercopy_abort("vmalloc", "no area", to_user, 0, n); - return; - } - offset = ptr - area->addr; - if (offset + n > get_vm_area_size(area)) + if (n > area->va_end - addr) { + offset = addr - area->va_start; usercopy_abort("vmalloc", NULL, to_user, offset, n); + } return; } @@ -196,8 +194,8 @@ static inline void check_heap_object(const void *ptr, unsigned long n, /* Check slab allocator for flags and size. */ __check_heap_object(ptr, n, folio_slab(folio), to_user); } else if (folio_test_large(folio)) { - unsigned long offset = ptr - folio_address(folio); - if (offset + n > folio_size(folio)) + offset = ptr - folio_address(folio); + if (n > folio_size(folio) - offset) usercopy_abort("page alloc", NULL, to_user, offset, n); } } |