From: Kees Cook <keescook@chromium.org>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Kees Cook <keescook@chromium.org>, Christoph Hellwig <hch@lst.de>,
Nathan Chancellor <natechancellor@gmail.com>,
Arnd Bergmann <arnd@arndb.de>, Tejun Heo <tj@kernel.org>,
Alexander Viro <viro@zeniv.linux.org.uk>,
"Rafael J. Wysocki" <rafael@kernel.org>,
Shuah Khan <shuah@kernel.org>,
Nathan Chancellor <nathan@kernel.org>,
Nick Desaulniers <ndesaulniers@google.com>,
Andrew Morton <akpm@linux-foundation.org>,
Kefeng Wang <wangkefeng.wang@huawei.com>,
"Matthew Wilcox (Oracle)" <willy@infradead.org>,
linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
linux-kselftest@vger.kernel.org,
clang-built-linux@googlegroups.com,
Michal Hocko <mhocko@suse.com>,
Alexey Dobriyan <adobriyan@gmail.com>,
Lee Duncan <lduncan@suse.com>, Chris Leech <cleech@redhat.com>,
Adam Nichols <adam@grimm-co.com>,
linux-hardening@vger.kernel.org
Subject: [PATCH v4 1/3] lkdtm/heap: Add vmalloc linear overflow test
Date: Thu, 1 Apr 2021 15:13:18 -0700 [thread overview]
Message-ID: <20210401221320.2717732-2-keescook@chromium.org> (raw)
In-Reply-To: <20210401221320.2717732-1-keescook@chromium.org>
Similar to the existing slab overflow and stack exhaustion tests, add
VMALLOC_LINEAR_OVERFLOW (and rename the slab test SLAB_LINEAR_OVERFLOW).
Signed-off-by: Kees Cook <keescook@chromium.org>
---
drivers/misc/lkdtm/core.c | 3 ++-
drivers/misc/lkdtm/heap.c | 21 ++++++++++++++++++++-
drivers/misc/lkdtm/lkdtm.h | 3 ++-
tools/testing/selftests/lkdtm/tests.txt | 3 ++-
4 files changed, 26 insertions(+), 4 deletions(-)
diff --git a/drivers/misc/lkdtm/core.c b/drivers/misc/lkdtm/core.c
index b2aff4d87c01..c3a5ad21b3d2 100644
--- a/drivers/misc/lkdtm/core.c
+++ b/drivers/misc/lkdtm/core.c
@@ -119,7 +119,8 @@ static const struct crashtype crashtypes[] = {
CRASHTYPE(UNALIGNED_LOAD_STORE_WRITE),
CRASHTYPE(FORTIFY_OBJECT),
CRASHTYPE(FORTIFY_SUBOBJECT),
- CRASHTYPE(OVERWRITE_ALLOCATION),
+ CRASHTYPE(SLAB_LINEAR_OVERFLOW),
+ CRASHTYPE(VMALLOC_LINEAR_OVERFLOW),
CRASHTYPE(WRITE_AFTER_FREE),
CRASHTYPE(READ_AFTER_FREE),
CRASHTYPE(WRITE_BUDDY_AFTER_FREE),
diff --git a/drivers/misc/lkdtm/heap.c b/drivers/misc/lkdtm/heap.c
index 1323bc16f113..5d491c22e09a 100644
--- a/drivers/misc/lkdtm/heap.c
+++ b/drivers/misc/lkdtm/heap.c
@@ -5,18 +5,37 @@
*/
#include "lkdtm.h"
#include <linux/slab.h>
+#include <linux/vmalloc.h>
#include <linux/sched.h>
static struct kmem_cache *double_free_cache;
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);
diff --git a/drivers/misc/lkdtm/lkdtm.h b/drivers/misc/lkdtm/lkdtm.h
index 5ae48c64df24..5a852d0beee0 100644
--- a/drivers/misc/lkdtm/lkdtm.h
+++ b/drivers/misc/lkdtm/lkdtm.h
@@ -38,7 +38,8 @@ void lkdtm_FORTIFY_SUBOBJECT(void);
/* heap.c */
void __init lkdtm_heap_init(void);
void __exit lkdtm_heap_exit(void);
-void lkdtm_OVERWRITE_ALLOCATION(void);
+void lkdtm_VMALLOC_LINEAR_OVERFLOW(void);
+void lkdtm_SLAB_LINEAR_OVERFLOW(void);
void lkdtm_WRITE_AFTER_FREE(void);
void lkdtm_READ_AFTER_FREE(void);
void lkdtm_WRITE_BUDDY_AFTER_FREE(void);
diff --git a/tools/testing/selftests/lkdtm/tests.txt b/tools/testing/selftests/lkdtm/tests.txt
index 11ef159be0fd..322a1d2439e3 100644
--- a/tools/testing/selftests/lkdtm/tests.txt
+++ b/tools/testing/selftests/lkdtm/tests.txt
@@ -15,7 +15,8 @@ UNSET_SMEP CR4 bits went missing
DOUBLE_FAULT
CORRUPT_PAC
UNALIGNED_LOAD_STORE_WRITE
-#OVERWRITE_ALLOCATION Corrupts memory on failure
+VMALLOC_LINEAR_OVERFLOW
+SLAB_LINEAR_OVERFLOW
#WRITE_AFTER_FREE Corrupts memory on failure
READ_AFTER_FREE
#WRITE_BUDDY_AFTER_FREE Corrupts memory on failure
--
2.25.1
next prev parent reply other threads:[~2021-04-01 22:13 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-01 22:13 [PATCH v4 0/3] sysfs: Unconditionally use vmalloc for buffer Kees Cook
2021-04-01 22:13 ` Kees Cook [this message]
2021-04-01 22:13 ` [PATCH v4 2/3] seq_file: Fix clang warning for NULL pointer arithmetic Kees Cook
2021-04-01 22:13 ` [PATCH v4 3/3] sysfs: Unconditionally use vmalloc for buffer Kees Cook
2021-04-02 6:32 ` Christoph Hellwig
2021-04-02 21:23 ` Kees Cook
2021-04-05 14:05 ` [sysfs] 5f65c1f63b: WARNING:at_fs/sysfs/file.c:#sysfs_kf_seq_start kernel test robot
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