Commit ca90800a authored by Kees Cook's avatar Kees Cook

test_overflow: Add memory allocation overflow tests

Make sure that the memory allocators are behaving as expected in the face
of overflows of multiplied arguments or when using the array_size()-family
helpers.

Example output of new tests (with the expected __alloc_pages_slowpath
and vmalloc warnings about refusing giant allocations removed):

[   93.062076] test_overflow: kmalloc detected saturation
[   93.062988] test_overflow: kmalloc_node detected saturation
[   93.063818] test_overflow: kzalloc detected saturation
[   93.064539] test_overflow: kzalloc_node detected saturation
[   93.120386] test_overflow: kvmalloc detected saturation
[   93.143458] test_overflow: kvmalloc_node detected saturation
[   93.166861] test_overflow: kvzalloc detected saturation
[   93.189924] test_overflow: kvzalloc_node detected saturation
[   93.221671] test_overflow: vmalloc detected saturation
[   93.246326] test_overflow: vmalloc_node detected saturation
[   93.270260] test_overflow: vzalloc detected saturation
[   93.293824] test_overflow: vzalloc_node detected saturation
[   93.294597] test_overflow: devm_kmalloc detected saturation
[   93.295383] test_overflow: devm_kzalloc detected saturation
[   93.296217] test_overflow: all tests passed
Signed-off-by: default avatarKees Cook <keescook@chromium.org>
parent 610b15c5
......@@ -4,11 +4,15 @@
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/device.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/overflow.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/vmalloc.h>
#define DEFINE_TEST_ARRAY(t) \
static const struct test_ ## t { \
......@@ -283,11 +287,117 @@ static int __init test_overflow_calculation(void)
return err;
}
/*
* Deal with the various forms of allocator arguments. See comments above
* the DEFINE_TEST_ALLOC() instances for mapping of the "bits".
*/
#define alloc010(alloc, arg, sz) alloc(sz, GFP_KERNEL)
#define alloc011(alloc, arg, sz) alloc(sz, GFP_KERNEL, NUMA_NO_NODE)
#define alloc000(alloc, arg, sz) alloc(sz)
#define alloc001(alloc, arg, sz) alloc(sz, NUMA_NO_NODE)
#define alloc110(alloc, arg, sz) alloc(arg, sz, GFP_KERNEL)
#define free0(free, arg, ptr) free(ptr)
#define free1(free, arg, ptr) free(arg, ptr)
/* Wrap around to 8K */
#define TEST_SIZE (9 << PAGE_SHIFT)
#define DEFINE_TEST_ALLOC(func, free_func, want_arg, want_gfp, want_node)\
static int __init test_ ## func (void *arg) \
{ \
volatile size_t a = TEST_SIZE; \
volatile size_t b = (SIZE_MAX / TEST_SIZE) + 1; \
void *ptr; \
\
/* Tiny allocation test. */ \
ptr = alloc ## want_arg ## want_gfp ## want_node (func, arg, 1);\
if (!ptr) { \
pr_warn(#func " failed regular allocation?!\n"); \
return 1; \
} \
free ## want_arg (free_func, arg, ptr); \
\
/* Wrapped allocation test. */ \
ptr = alloc ## want_arg ## want_gfp ## want_node (func, arg, \
a * b); \
if (!ptr) { \
pr_warn(#func " unexpectedly failed bad wrapping?!\n"); \
return 1; \
} \
free ## want_arg (free_func, arg, ptr); \
\
/* Saturated allocation test. */ \
ptr = alloc ## want_arg ## want_gfp ## want_node (func, arg, \
array_size(a, b)); \
if (ptr) { \
pr_warn(#func " missed saturation!\n"); \
free ## want_arg (free_func, arg, ptr); \
return 1; \
} \
pr_info(#func " detected saturation\n"); \
return 0; \
}
/*
* Allocator uses a trailing node argument --------+ (e.g. kmalloc_node())
* Allocator uses the gfp_t argument -----------+ | (e.g. kmalloc())
* Allocator uses a special leading argument + | | (e.g. devm_kmalloc())
* | | |
*/
DEFINE_TEST_ALLOC(kmalloc, kfree, 0, 1, 0);
DEFINE_TEST_ALLOC(kmalloc_node, kfree, 0, 1, 1);
DEFINE_TEST_ALLOC(kzalloc, kfree, 0, 1, 0);
DEFINE_TEST_ALLOC(kzalloc_node, kfree, 0, 1, 1);
DEFINE_TEST_ALLOC(vmalloc, vfree, 0, 0, 0);
DEFINE_TEST_ALLOC(vmalloc_node, vfree, 0, 0, 1);
DEFINE_TEST_ALLOC(vzalloc, vfree, 0, 0, 0);
DEFINE_TEST_ALLOC(vzalloc_node, vfree, 0, 0, 1);
DEFINE_TEST_ALLOC(kvmalloc, kvfree, 0, 1, 0);
DEFINE_TEST_ALLOC(kvmalloc_node, kvfree, 0, 1, 1);
DEFINE_TEST_ALLOC(kvzalloc, kvfree, 0, 1, 0);
DEFINE_TEST_ALLOC(kvzalloc_node, kvfree, 0, 1, 1);
DEFINE_TEST_ALLOC(devm_kmalloc, devm_kfree, 1, 1, 0);
DEFINE_TEST_ALLOC(devm_kzalloc, devm_kfree, 1, 1, 0);
static int __init test_overflow_allocation(void)
{
const char device_name[] = "overflow-test";
struct device *dev;
int err = 0;
/* Create dummy device for devm_kmalloc()-family tests. */
dev = root_device_register(device_name);
if (!dev) {
pr_warn("Cannot register test device\n");
return 1;
}
err |= test_kmalloc(NULL);
err |= test_kmalloc_node(NULL);
err |= test_kzalloc(NULL);
err |= test_kzalloc_node(NULL);
err |= test_kvmalloc(NULL);
err |= test_kvmalloc_node(NULL);
err |= test_kvzalloc(NULL);
err |= test_kvzalloc_node(NULL);
err |= test_vmalloc(NULL);
err |= test_vmalloc_node(NULL);
err |= test_vzalloc(NULL);
err |= test_vzalloc_node(NULL);
err |= test_devm_kmalloc(dev);
err |= test_devm_kzalloc(dev);
device_unregister(dev);
return err;
}
static int __init test_module_init(void)
{
int err = 0;
err |= test_overflow_calculation();
err |= test_overflow_allocation();
if (err) {
pr_warn("FAIL!\n");
......
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