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authorKees Cook <keescook@chromium.org>2018-05-10 16:40:03 -0700
committerKees Cook <keescook@chromium.org>2018-06-05 12:16:51 -0700
commitca90800a91ba723d78ded634d037c1d2df8b54d6 (patch)
tree5c709a41d95010d66d7a3f22607614ae117f66d2 /lib
parent610b15c50e86eb1e4b77274fabcaea29ac72d6a8 (diff)
downloadlinux-ca90800a91ba723d78ded634d037c1d2df8b54d6.tar.bz2
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: Kees Cook <keescook@chromium.org>
Diffstat (limited to 'lib')
-rw-r--r--lib/test_overflow.c110
1 files changed, 110 insertions, 0 deletions
diff --git a/lib/test_overflow.c b/lib/test_overflow.c
index 501ed86205c4..aecbbb217305 100644
--- a/lib/test_overflow.c
+++ b/lib/test_overflow.c
@@ -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");