Merge tag 'hardening-v5.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull hardening updates from Kees Cook:

 - Fix Sparse warnings with randomizd kstack (GONG, Ruiqi)

 - Replace uintptr_t with unsigned long in usercopy (Jason A. Donenfeld)

 - Fix Clang -Wforward warning in LKDTM (Justin Stitt)

 - Fix comment to correctly refer to STRICT_DEVMEM (Lukas Bulwahn)

 - Introduce dm-verity binding logic to LoadPin LSM (Matthias Kaehlcke)

 - Clean up warnings and overflow and KASAN tests (Kees Cook)

* tag 'hardening-v5.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  dm: verity-loadpin: Drop use of dm_table_get_num_targets()
  kasan: test: Silence GCC 12 warnings
  drivers: lkdtm: fix clang -Wformat warning
  x86: mm: refer to the intended config STRICT_DEVMEM in a comment
  dm: verity-loadpin: Use CONFIG_SECURITY_LOADPIN_VERITY for conditional compilation
  LoadPin: Enable loading from trusted dm-verity devices
  dm: Add verity helpers for LoadPin
  stack: Declare {randomize_,}kstack_offset to fix Sparse warnings
  lib: overflow: Do not define 64-bit tests on 32-bit
  MAINTAINERS: Add a general "kernel hardening" section
  usercopy: use unsigned long instead of uintptr_t

2 files changed, 16 insertions, 0 deletions

diff --git a/lib/overflow_kunit.c b/lib/overflow_kunit.c
index 475f0c064bf6..7e3e43679b73 100644
--- a/lib/overflow_kunit.c
+++ b/lib/overflow_kunit.c
@@ -91,6 +91,7 @@ DEFINE_TEST_ARRAY(u32) = {
 	{-4U, 5U, 1U, -9U, -20U, true, false, true},
 };
 
+#if BITS_PER_LONG == 64
 DEFINE_TEST_ARRAY(u64) = {
 	{0, 0, 0, 0, 0, false, false, false},
 	{1, 1, 2, 0, 1, false, false, false},
@@ -114,6 +115,7 @@ DEFINE_TEST_ARRAY(u64) = {
 	 false, true, false},
 	{-15ULL, 10ULL, -5ULL, -25ULL, -150ULL, false, false, true},
 };
+#endif
 
 DEFINE_TEST_ARRAY(s8) = {
 	{0, 0, 0, 0, 0, false, false, false},
@@ -188,6 +190,8 @@ DEFINE_TEST_ARRAY(s32) = {
 	{S32_MIN, S32_MIN, 0, 0, 0, true, false, true},
 	{S32_MAX, S32_MAX, -2, 0, 1, true, false, true},
 };
+
+#if BITS_PER_LONG == 64
 DEFINE_TEST_ARRAY(s64) = {
 	{0, 0, 0, 0, 0, false, false, false},
 
@@ -216,6 +220,7 @@ DEFINE_TEST_ARRAY(s64) = {
 	{-128, -1, -129, -127, 128, false, false, false},
 	{0, -S64_MAX, -S64_MAX, S64_MAX, 0, false, false, false},
 };
+#endif
 
 #define check_one_op(t, fmt, op, sym, a, b, r, of) do {		\
 	t _r;							\
@@ -650,6 +655,7 @@ static struct kunit_case overflow_test_cases[] = {
 	KUNIT_CASE(s16_overflow_test),
 	KUNIT_CASE(u32_overflow_test),
 	KUNIT_CASE(s32_overflow_test),
+/* Clang 13 and earlier generate unwanted libcalls on 32-bit. */
 #if BITS_PER_LONG == 64
 	KUNIT_CASE(u64_overflow_test),
 	KUNIT_CASE(s64_overflow_test),
diff --git a/lib/test_kasan.c b/lib/test_kasan.c
index c233b1a4e984..58c1b01ccfe2 100644
--- a/lib/test_kasan.c
+++ b/lib/test_kasan.c
@@ -131,6 +131,7 @@ static void kmalloc_oob_right(struct kunit *test)
 	ptr = kmalloc(size, GFP_KERNEL);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
 
+	OPTIMIZER_HIDE_VAR(ptr);
 	/*
 	 * An unaligned access past the requested kmalloc size.
 	 * Only generic KASAN can precisely detect these.
@@ -159,6 +160,7 @@ static void kmalloc_oob_left(struct kunit *test)
 	ptr = kmalloc(size, GFP_KERNEL);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
 
+	OPTIMIZER_HIDE_VAR(ptr);
 	KUNIT_EXPECT_KASAN_FAIL(test, *ptr = *(ptr - 1));
 	kfree(ptr);
 }
@@ -171,6 +173,7 @@ static void kmalloc_node_oob_right(struct kunit *test)
 	ptr = kmalloc_node(size, GFP_KERNEL, 0);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
 
+	OPTIMIZER_HIDE_VAR(ptr);
 	KUNIT_EXPECT_KASAN_FAIL(test, ptr[0] = ptr[size]);
 	kfree(ptr);
 }
@@ -191,6 +194,7 @@ static void kmalloc_pagealloc_oob_right(struct kunit *test)
 	ptr = kmalloc(size, GFP_KERNEL);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
 
+	OPTIMIZER_HIDE_VAR(ptr);
 	KUNIT_EXPECT_KASAN_FAIL(test, ptr[size + OOB_TAG_OFF] = 0);
 
 	kfree(ptr);
@@ -271,6 +275,7 @@ static void kmalloc_large_oob_right(struct kunit *test)
 	ptr = kmalloc(size, GFP_KERNEL);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
 
+	OPTIMIZER_HIDE_VAR(ptr);
 	KUNIT_EXPECT_KASAN_FAIL(test, ptr[size] = 0);
 	kfree(ptr);
 }
@@ -410,6 +415,8 @@ static void kmalloc_oob_16(struct kunit *test)
 	ptr2 = kmalloc(sizeof(*ptr2), GFP_KERNEL);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr2);
 
+	OPTIMIZER_HIDE_VAR(ptr1);
+	OPTIMIZER_HIDE_VAR(ptr2);
 	KUNIT_EXPECT_KASAN_FAIL(test, *ptr1 = *ptr2);
 	kfree(ptr1);
 	kfree(ptr2);
@@ -756,6 +763,8 @@ static void ksize_unpoisons_memory(struct kunit *test)
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
 	real_size = ksize(ptr);
 
+	OPTIMIZER_HIDE_VAR(ptr);
+
 	/* This access shouldn't trigger a KASAN report. */
 	ptr[size] = 'x';
 
@@ -778,6 +787,7 @@ static void ksize_uaf(struct kunit *test)
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
 	kfree(ptr);
 
+	OPTIMIZER_HIDE_VAR(ptr);
 	KUNIT_EXPECT_KASAN_FAIL(test, ksize(ptr));
 	KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr)[0]);
 	KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr)[size]);