diff options
Diffstat (limited to 'mm/kmsan')
| -rw-r--r-- | mm/kmsan/core.c | 10 | ||||
| -rw-r--r-- | mm/kmsan/hooks.c | 13 | ||||
| -rw-r--r-- | mm/kmsan/kmsan_test.c | 16 |
3 files changed, 30 insertions, 9 deletions
diff --git a/mm/kmsan/core.c b/mm/kmsan/core.c index 1ea711786c52..8bca7fece47f 100644 --- a/mm/kmsan/core.c +++ b/mm/kmsan/core.c @@ -195,7 +195,8 @@ void kmsan_internal_set_shadow_origin(void *addr, size_t size, int b, u32 origin, bool checked) { u64 address = (u64)addr; - u32 *shadow_start, *origin_start; + void *shadow_start; + u32 *aligned_shadow, *origin_start; size_t pad = 0; KMSAN_WARN_ON(!kmsan_metadata_is_contiguous(addr, size)); @@ -214,9 +215,12 @@ void kmsan_internal_set_shadow_origin(void *addr, size_t size, int b, } __memset(shadow_start, b, size); - if (!IS_ALIGNED(address, KMSAN_ORIGIN_SIZE)) { + if (IS_ALIGNED(address, KMSAN_ORIGIN_SIZE)) { + aligned_shadow = shadow_start; + } else { pad = address % KMSAN_ORIGIN_SIZE; address -= pad; + aligned_shadow = shadow_start - pad; size += pad; } size = ALIGN(size, KMSAN_ORIGIN_SIZE); @@ -230,7 +234,7 @@ void kmsan_internal_set_shadow_origin(void *addr, size_t size, int b, * corresponding shadow slot is zero. */ for (int i = 0; i < size / KMSAN_ORIGIN_SIZE; i++) { - if (origin || !shadow_start[i]) + if (origin || !aligned_shadow[i]) origin_start[i] = origin; } } diff --git a/mm/kmsan/hooks.c b/mm/kmsan/hooks.c index 97de3d6194f0..90bee565b9bc 100644 --- a/mm/kmsan/hooks.c +++ b/mm/kmsan/hooks.c @@ -336,14 +336,16 @@ static void kmsan_handle_dma_page(const void *addr, size_t size, } /* Helper function to handle DMA data transfers. */ -void kmsan_handle_dma(struct page *page, size_t offset, size_t size, +void kmsan_handle_dma(phys_addr_t phys, size_t size, enum dma_data_direction dir) { - u64 page_offset, to_go, addr; + struct page *page = phys_to_page(phys); + u64 page_offset, to_go; + void *addr; - if (PageHighMem(page)) + if (PhysHighMem(phys)) return; - addr = (u64)page_address(page) + offset; + addr = page_to_virt(page); /* * The kernel may occasionally give us adjacent DMA pages not belonging * to the same allocation. Process them separately to avoid triggering @@ -366,8 +368,7 @@ void kmsan_handle_dma_sg(struct scatterlist *sg, int nents, int i; for_each_sg(sg, item, nents, i) - kmsan_handle_dma(sg_page(item), item->offset, item->length, - dir); + kmsan_handle_dma(sg_phys(item), item->length, dir); } /* Functions from kmsan-checks.h follow. */ diff --git a/mm/kmsan/kmsan_test.c b/mm/kmsan/kmsan_test.c index c6c5b2bbede0..902ec48b1e3e 100644 --- a/mm/kmsan/kmsan_test.c +++ b/mm/kmsan/kmsan_test.c @@ -556,6 +556,21 @@ DEFINE_TEST_MEMSETXX(16) DEFINE_TEST_MEMSETXX(32) DEFINE_TEST_MEMSETXX(64) +/* Test case: ensure that KMSAN does not access shadow memory out of bounds. */ +static void test_memset_on_guarded_buffer(struct kunit *test) +{ + void *buf = vmalloc(PAGE_SIZE); + + kunit_info(test, + "memset() on ends of guarded buffer should not crash\n"); + + for (size_t size = 0; size <= 128; size++) { + memset(buf, 0xff, size); + memset(buf + PAGE_SIZE - size, 0xff, size); + } + vfree(buf); +} + static noinline void fibonacci(int *array, int size, int start) { if (start < 2 || (start == size)) @@ -677,6 +692,7 @@ static struct kunit_case kmsan_test_cases[] = { KUNIT_CASE(test_memset16), KUNIT_CASE(test_memset32), KUNIT_CASE(test_memset64), + KUNIT_CASE(test_memset_on_guarded_buffer), KUNIT_CASE(test_long_origin_chain), KUNIT_CASE(test_stackdepot_roundtrip), KUNIT_CASE(test_unpoison_memory), |