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Date: Thu, 31 May 2018 17:42:22 -0700
From: Kees Cook <keescook@...omium.org>
To: Matthew Wilcox <mawilcox@...rosoft.com>
Cc: Kees Cook <keescook@...omium.org>,
Linus Torvalds <torvalds@...ux-foundation.org>,
Rasmus Villemoes <linux@...musvillemoes.dk>,
Matthew Wilcox <willy@...radead.org>,
LKML <linux-kernel@...r.kernel.org>,
Linux-MM <linux-mm@...ck.org>,
Kernel Hardening <kernel-hardening@...ts.openwall.com>
Subject: [PATCH v3 05/16] lib: overflow: Add memory allocation overflow tests
Make sure that the memory allocators are behaving as expected in the face
of overflows.
Signed-off-by: Kees Cook <keescook@...omium.org>
---
lib/test_overflow.c | 109 ++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 109 insertions(+)
diff --git a/lib/test_overflow.c b/lib/test_overflow.c
index 482d71c880fa..3f4457ea7d7c 100644
--- a/lib/test_overflow.c
+++ b/lib/test_overflow.c
@@ -9,6 +9,9 @@
#include <linux/module.h>
#include <linux/overflow.h>
#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/device.h>
+#include <linux/mm.h>
#define DEFINE_TEST_ARRAY(t) \
static const struct test_ ## t { \
@@ -294,11 +297,117 @@ 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");
--
2.17.0
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