diff options
Diffstat (limited to 'mm/usercopy.c')
| -rw-r--r-- | mm/usercopy.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/mm/usercopy.c b/mm/usercopy.c index a9852b24715d..f8d74e09f8e4 100644 --- a/mm/usercopy.c +++ b/mm/usercopy.c @@ -15,6 +15,7 @@ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/mm.h> +#include <linux/highmem.h> #include <linux/slab.h> #include <linux/sched.h> #include <linux/sched/task.h> @@ -121,7 +122,7 @@ static inline const char *check_kernel_text_object(const void *ptr, static inline const char *check_bogus_address(const void *ptr, unsigned long n) { /* Reject if object wraps past end of memory. */ - if ((unsigned long)ptr + n < (unsigned long)ptr) + if ((unsigned long)ptr + (n - 1) < (unsigned long)ptr) return "<wrapped address>"; /* Reject if NULL or ZERO-allocation. */ @@ -203,7 +204,12 @@ static inline const char *check_heap_object(const void *ptr, unsigned long n, if (!virt_addr_valid(ptr)) return NULL; - page = virt_to_head_page(ptr); + /* + * When CONFIG_HIGHMEM=y, kmap_to_page() will give either the + * highmem page or fallback to virt_to_page(). The following + * is effectively a highmem-aware virt_to_head_page(). + */ + page = compound_head(kmap_to_page((void *)ptr)); /* Check slab allocator for flags and size. */ if (PageSlab(page)) |