The quilt patch titled
Subject: mm, kasan: instrument copy_from/to_kernel_nofault
has been removed from the -mm tree. Its filename was
mm-instrument-copy_from-to_kernel_nofault.patch
This patch was dropped because an updated version will be issued
------------------------------------------------------
From: Sabyrzhan Tasbolatov <snovitoll@xxxxxxxxx>
Subject: mm, kasan: instrument copy_from/to_kernel_nofault
Date: Fri, 27 Sep 2024 20:14:38 +0500
Instrument copy_from_kernel_nofault(), copy_to_kernel_nofault() with
instrument_memcpy_before() for KASAN, KCSAN checks and
instrument_memcpy_after() for KMSAN.
Tested on x86_64 and arm64 with CONFIG_KASAN_SW_TAGS. On arm64 with
CONFIG_KASAN_HW_TAGS, kunit test currently fails. Need more clarification
on it - currently, disabled in kunit test.
Link: https://lkml.kernel.org/r/20240927151438.2143936-1-snovitoll@xxxxxxxxx
Signed-off-by: Sabyrzhan Tasbolatov <snovitoll@xxxxxxxxx>
Reported-by: Andrey Konovalov <andreyknvl@xxxxxxxxx>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=210505
Cc: Alexander Potapenko <glider@xxxxxxxxxx>
Cc: Andrey Ryabinin <ryabinin.a.a@xxxxxxxxx>
Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Cc: Vincenzo Frascino <vincenzo.frascino@xxxxxxx>
[snovitoll@xxxxxxxxx: proper instrument _kernel_nofault]
Link: https://lkml.kernel.org/r/20240930102405.2227124-1-snovitoll@xxxxxxxxx
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/kasan/kasan_test_c.c | 31 +++++++++++++++++++++++++++++++
mm/maccess.c | 6 ++++--
2 files changed, 35 insertions(+), 2 deletions(-)
--- a/mm/kasan/kasan_test_c.c~mm-instrument-copy_from-to_kernel_nofault
+++ a/mm/kasan/kasan_test_c.c
@@ -1954,6 +1954,36 @@ static void rust_uaf(struct kunit *test)
KUNIT_EXPECT_KASAN_FAIL(test, kasan_test_rust_uaf());
}
+static void copy_from_to_kernel_nofault_oob(struct kunit *test)
+{
+ char *ptr;
+ char buf[128];
+ size_t size = sizeof(buf);
+
+ /* Not detecting fails currently with HW_TAGS */
+ KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_KASAN_HW_TAGS);
+
+ ptr = kmalloc(size - KASAN_GRANULE_SIZE, GFP_KERNEL);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
+ OPTIMIZER_HIDE_VAR(ptr);
+
+ if (IS_ENABLED(CONFIG_KASAN_SW_TAGS)) {
+ /* Check that the returned pointer is tagged. */
+ KUNIT_EXPECT_GE(test, (u8)get_tag(ptr), (u8)KASAN_TAG_MIN);
+ KUNIT_EXPECT_LT(test, (u8)get_tag(ptr), (u8)KASAN_TAG_KERNEL);
+ }
+
+ KUNIT_EXPECT_KASAN_FAIL(test,
+ copy_from_kernel_nofault(&buf[0], ptr, size));
+ KUNIT_EXPECT_KASAN_FAIL(test,
+ copy_from_kernel_nofault(ptr, &buf[0], size));
+ KUNIT_EXPECT_KASAN_FAIL(test,
+ copy_to_kernel_nofault(&buf[0], ptr, size));
+ KUNIT_EXPECT_KASAN_FAIL(test,
+ copy_to_kernel_nofault(ptr, &buf[0], size));
+ kfree(ptr);
+}
+
static struct kunit_case kasan_kunit_test_cases[] = {
KUNIT_CASE(kmalloc_oob_right),
KUNIT_CASE(kmalloc_oob_left),
@@ -2027,6 +2057,7 @@ static struct kunit_case kasan_kunit_tes
KUNIT_CASE(match_all_not_assigned),
KUNIT_CASE(match_all_ptr_tag),
KUNIT_CASE(match_all_mem_tag),
+ KUNIT_CASE(copy_from_to_kernel_nofault_oob),
KUNIT_CASE(rust_uaf),
{}
};
--- a/mm/maccess.c~mm-instrument-copy_from-to_kernel_nofault
+++ a/mm/maccess.c
@@ -15,7 +15,7 @@ bool __weak copy_from_kernel_nofault_all
#define copy_from_kernel_nofault_loop(dst, src, len, type, err_label) \
while (len >= sizeof(type)) { \
- __get_kernel_nofault(dst, src, type, err_label); \
+ __get_kernel_nofault(dst, src, type, err_label); \
dst += sizeof(type); \
src += sizeof(type); \
len -= sizeof(type); \
@@ -32,6 +32,7 @@ long copy_from_kernel_nofault(void *dst,
return -ERANGE;
pagefault_disable();
+ instrument_read(src, size);
if (!(align & 7))
copy_from_kernel_nofault_loop(dst, src, size, u64, Efault);
if (!(align & 3))
@@ -49,7 +50,7 @@ EXPORT_SYMBOL_GPL(copy_from_kernel_nofau
#define copy_to_kernel_nofault_loop(dst, src, len, type, err_label) \
while (len >= sizeof(type)) { \
- __put_kernel_nofault(dst, src, type, err_label); \
+ __put_kernel_nofault(dst, src, type, err_label); \
dst += sizeof(type); \
src += sizeof(type); \
len -= sizeof(type); \
@@ -63,6 +64,7 @@ long copy_to_kernel_nofault(void *dst, c
align = (unsigned long)dst | (unsigned long)src;
pagefault_disable();
+ instrument_write(dst, size);
if (!(align & 7))
copy_to_kernel_nofault_loop(dst, src, size, u64, Efault);
if (!(align & 3))
_
Patches currently in -mm which might be from snovitoll@xxxxxxxxx are
