#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>
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. */
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))
/*
* Validates that the given object is:
* - not bogus address
- * - known-safe heap or stack object
+ * - fully contained by stack (or stack frame, when available)
+ * - fully within SLAB object (or object whitelist area, when available)
* - not in kernel text
*/
void __check_object_size(const void *ptr, unsigned long n, bool to_user)
if (err)
goto report;
- /* Check for bad heap object. */
- err = check_heap_object(ptr, n, to_user);
- if (err)
- goto report;
-
/* Check for bad stack object. */
switch (check_stack_object(ptr, n)) {
case NOT_STACK:
goto report;
}
+ /* Check for bad heap object. */
+ check_heap_object(ptr, n, to_user);
+
/* Check for object in kernel to avoid text exposure. */
err = check_kernel_text_object(ptr, n);
if (!err)