+ kasan-add-atomic-tests.patch added to mm-unstable branch

+ kasan-add-atomic-tests.patch added to mm-unstable branch

[Andrew Morton]

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The patch titled
     Subject: kasan: add atomic tests
has been added to the -mm mm-unstable branch.  Its filename is
     kasan-add-atomic-tests.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/kasan-add-atomic-tests.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Paul Heidekrüger <paul.heidekrueger@tum.de>
Subject: kasan: add atomic tests
Date: Fri, 2 Feb 2024 11:32:59 +0000

Test that KASan can detect some unsafe atomic accesses.

As discussed in the linked thread below, these tests attempt to cover
the most common uses of atomics and, therefore, aren't exhaustive.

Link: https://lkml.kernel.org/r/20240202113259.3045705-1-paul.heidekrueger@tum.de
Signed-off-by: Paul Heidekrüger <paul.heidekrueger@tum.de>
Cc: Marco Elver <elver@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Link: https://lore.kernel.org/all/20240131210041.686657-1-paul.heidekrueger@tum.de/T/#u
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=214055
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/kasan/kasan_test.c |   79 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 79 insertions(+)

--- a/mm/kasan/kasan_test.c~kasan-add-atomic-tests
+++ a/mm/kasan/kasan_test.c
@@ -697,6 +697,84 @@ static void kmalloc_uaf3(struct kunit *t
 	KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr1)[8]);
 }
 
+static void kasan_atomics_helper(struct kunit *test, void *unsafe, void *safe)
+{
+	int *i_unsafe = (int *)unsafe;
+
+	KUNIT_EXPECT_KASAN_FAIL(test, READ_ONCE(*i_unsafe));
+	KUNIT_EXPECT_KASAN_FAIL(test, WRITE_ONCE(*i_unsafe, 42));
+	KUNIT_EXPECT_KASAN_FAIL(test, smp_load_acquire(i_unsafe));
+	KUNIT_EXPECT_KASAN_FAIL(test, smp_store_release(i_unsafe, 42));
+
+	KUNIT_EXPECT_KASAN_FAIL(test, atomic_read(unsafe));
+	KUNIT_EXPECT_KASAN_FAIL(test, atomic_set(unsafe, 42));
+	KUNIT_EXPECT_KASAN_FAIL(test, atomic_add(42, unsafe));
+	KUNIT_EXPECT_KASAN_FAIL(test, atomic_sub(42, unsafe));
+	KUNIT_EXPECT_KASAN_FAIL(test, atomic_inc(unsafe));
+	KUNIT_EXPECT_KASAN_FAIL(test, atomic_dec(unsafe));
+	KUNIT_EXPECT_KASAN_FAIL(test, atomic_and(42, unsafe));
+	KUNIT_EXPECT_KASAN_FAIL(test, atomic_andnot(42, unsafe));
+	KUNIT_EXPECT_KASAN_FAIL(test, atomic_or(42, unsafe));
+	KUNIT_EXPECT_KASAN_FAIL(test, atomic_xor(42, unsafe));
+	KUNIT_EXPECT_KASAN_FAIL(test, atomic_xchg(unsafe, 42));
+	KUNIT_EXPECT_KASAN_FAIL(test, atomic_cmpxchg(unsafe, 21, 42));
+	KUNIT_EXPECT_KASAN_FAIL(test, atomic_try_cmpxchg(unsafe, safe, 42));
+	KUNIT_EXPECT_KASAN_FAIL(test, atomic_try_cmpxchg(safe, unsafe, 42));
+	KUNIT_EXPECT_KASAN_FAIL(test, atomic_sub_and_test(42, unsafe));
+	KUNIT_EXPECT_KASAN_FAIL(test, atomic_dec_and_test(unsafe));
+	KUNIT_EXPECT_KASAN_FAIL(test, atomic_inc_and_test(unsafe));
+	KUNIT_EXPECT_KASAN_FAIL(test, atomic_add_negative(42, unsafe));
+	KUNIT_EXPECT_KASAN_FAIL(test, atomic_add_unless(unsafe, 21, 42));
+	KUNIT_EXPECT_KASAN_FAIL(test, atomic_inc_not_zero(unsafe));
+	KUNIT_EXPECT_KASAN_FAIL(test, atomic_inc_unless_negative(unsafe));
+	KUNIT_EXPECT_KASAN_FAIL(test, atomic_dec_unless_positive(unsafe));
+	KUNIT_EXPECT_KASAN_FAIL(test, atomic_dec_if_positive(unsafe));
+
+	KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_read(unsafe));
+	KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_set(unsafe, 42));
+	KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_add(42, unsafe));
+	KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_sub(42, unsafe));
+	KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_inc(unsafe));
+	KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_dec(unsafe));
+	KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_and(42, unsafe));
+	KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_andnot(42, unsafe));
+	KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_or(42, unsafe));
+	KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_xor(42, unsafe));
+	KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_xchg(unsafe, 42));
+	KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_cmpxchg(unsafe, 21, 42));
+	KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_try_cmpxchg(unsafe, safe, 42));
+	KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_try_cmpxchg(safe, unsafe, 42));
+	KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_sub_and_test(42, unsafe));
+	KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_dec_and_test(unsafe));
+	KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_inc_and_test(unsafe));
+	KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_add_negative(42, unsafe));
+	KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_add_unless(unsafe, 21, 42));
+	KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_inc_not_zero(unsafe));
+	KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_inc_unless_negative(unsafe));
+	KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_dec_unless_positive(unsafe));
+	KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_dec_if_positive(unsafe));
+}
+
+static void kasan_atomics(struct kunit *test)
+{
+	void *a1, *a2;
+
+	/*
+	 * Just as with kasan_bitops_tags(), we allocate 48 bytes of memory such
+	 * that the following 16 bytes will make up the redzone.
+	 */
+	a1 = kzalloc(48, GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, a1);
+	a2 = kzalloc(sizeof(int), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, a1);
+
+	/* Use atomics to access the redzone. */
+	kasan_atomics_helper(test, a1 + 48, a2);
+
+	kfree(a1);
+	kfree(a2);
+}
+
 static void kmalloc_double_kzfree(struct kunit *test)
 {
 	char *ptr;
@@ -1883,6 +1961,7 @@ static struct kunit_case kasan_kunit_tes
 	KUNIT_CASE(kasan_strings),
 	KUNIT_CASE(kasan_bitops_generic),
 	KUNIT_CASE(kasan_bitops_tags),
+	KUNIT_CASE(kasan_atomics),
 	KUNIT_CASE(vmalloc_helpers_tags),
 	KUNIT_CASE(vmalloc_oob),
 	KUNIT_CASE(vmap_tags),
_

Patches currently in -mm which might be from paul.heidekrueger@tum.de are

kasan-add-atomic-tests.patch