diff options
Diffstat (limited to 'drivers/misc/lkdtm/heap.c')
| -rw-r--r-- | drivers/misc/lkdtm/heap.c | 22 |
1 files changed, 21 insertions, 1 deletions
diff --git a/drivers/misc/lkdtm/heap.c b/drivers/misc/lkdtm/heap.c index 1323bc16f113..36be5e353cd0 100644 --- a/drivers/misc/lkdtm/heap.c +++ b/drivers/misc/lkdtm/heap.c @@ -5,6 +5,7 @@ */ #include "lkdtm.h" #include <linux/slab.h> +#include <linux/vmalloc.h> #include <linux/sched.h> static struct kmem_cache *double_free_cache; @@ -12,17 +13,36 @@ static struct kmem_cache *a_cache; static struct kmem_cache *b_cache; /* + * If there aren't guard pages, it's likely that a consecutive allocation will + * let us overflow into the second allocation without overwriting something real. + */ +void lkdtm_VMALLOC_LINEAR_OVERFLOW(void) +{ + char *one, *two; + + one = vzalloc(PAGE_SIZE); + two = vzalloc(PAGE_SIZE); + + pr_info("Attempting vmalloc linear overflow ...\n"); + memset(one, 0xAA, PAGE_SIZE + 1); + + vfree(two); + vfree(one); +} + +/* * This tries to stay within the next largest power-of-2 kmalloc cache * to avoid actually overwriting anything important if it's not detected * correctly. */ -void lkdtm_OVERWRITE_ALLOCATION(void) +void lkdtm_SLAB_LINEAR_OVERFLOW(void) { size_t len = 1020; u32 *data = kmalloc(len, GFP_KERNEL); if (!data) return; + pr_info("Attempting slab linear overflow ...\n"); data[1024 / sizeof(u32)] = 0x12345678; kfree(data); } |