diff --git a/Android.bp b/Android.bp index f6a7a9c..a2bab52 100644 --- a/Android.bp +++ b/Android.bp @@ -28,6 +28,7 @@ common_cflags = [ "-DN_ARENA=1", "-DCONFIG_STATS=true", "-DCONFIG_SELF_INIT=false", + "-DCONFIG_BLOCK_OPS_CHECK_SIZE=false", ] cc_defaults { diff --git a/CREDITS b/CREDITS index 31b6875..1832cc5 100644 --- a/CREDITS +++ b/CREDITS @@ -23,6 +23,12 @@ h_malloc.c open-addressed hash table (regions_grow, regions_insert, regions_find ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. +h_malloc.c block operations (h_memcpy_real, h_memmove_real, h_memset_real): + + Copyright (C) 2022, 2023 struct + Copyright (C) 2023 David Carlier + Apache-2.0 + libdivide: Copyright (C) 2010 - 2019 ridiculous_fish, diff --git a/Makefile b/Makefile index f33f88e..37d35f7 100644 --- a/Makefile +++ b/Makefile @@ -89,6 +89,10 @@ ifeq (,$(filter $(CONFIG_SELF_INIT),true false)) $(error CONFIG_SELF_INIT must be true or false) endif +ifeq (,$(filter $(CONFIG_BLOCK_OPS_CHECK_SIZE),true false)) + $(error CONFIG_BLOCK_OPS_CHECK_SIZE must be true or false) +endif + CPPFLAGS += \ -DCONFIG_SEAL_METADATA=$(CONFIG_SEAL_METADATA) \ -DZERO_ON_FREE=$(CONFIG_ZERO_ON_FREE) \ @@ -108,7 +112,8 @@ CPPFLAGS += \ -DCONFIG_CLASS_REGION_SIZE=$(CONFIG_CLASS_REGION_SIZE) \ -DN_ARENA=$(CONFIG_N_ARENA) \ -DCONFIG_STATS=$(CONFIG_STATS) \ - -DCONFIG_SELF_INIT=$(CONFIG_SELF_INIT) + -DCONFIG_SELF_INIT=$(CONFIG_SELF_INIT) \ + -DCONFIG_BLOCK_OPS_CHECK_SIZE=$(CONFIG_BLOCK_OPS_CHECK_SIZE) $(OUT)/libhardened_malloc$(SUFFIX).so: $(OBJECTS) | $(OUT) $(CC) $(CFLAGS) $(LDFLAGS) -shared $^ $(LDLIBS) -o $@ diff --git a/README.md b/README.md index 6a1a91b..a3ba892 100644 --- a/README.md +++ b/README.md @@ -276,6 +276,10 @@ The following boolean configuration options are available: hardware, which may become drastically lower in the future. Whether or not this feature is enabled, the metadata is all contained within an isolated memory region with high entropy random guard regions around it. +* `CONFIG_BLOCK_OPS_CHECK_SIZE`: `true` or `false` (default) to ensure length + parameter of the memcpy/memmove/memset block operations are within + approximate bounds to minimize buffer overflows. Note, memset override is + currently disabled due to being broken. The following integer configuration options are available: diff --git a/config/default.mk b/config/default.mk index 71b1cc4..b139c43 100644 --- a/config/default.mk +++ b/config/default.mk @@ -21,3 +21,4 @@ CONFIG_CLASS_REGION_SIZE := 34359738368 # 32GiB CONFIG_N_ARENA := 4 CONFIG_STATS := false CONFIG_SELF_INIT := true +CONFIG_BLOCK_OPS_CHECK_SIZE := false diff --git a/config/light.mk b/config/light.mk index 88a0e1f..7edd423 100644 --- a/config/light.mk +++ b/config/light.mk @@ -21,3 +21,4 @@ CONFIG_CLASS_REGION_SIZE := 34359738368 # 32GiB CONFIG_N_ARENA := 4 CONFIG_STATS := false CONFIG_SELF_INIT := true +CONFIG_BLOCK_OPS_CHECK_SIZE := false diff --git a/h_malloc.c b/h_malloc.c index 6221d0b..73544cd 100644 --- a/h_malloc.c +++ b/h_malloc.c @@ -528,7 +528,7 @@ static void set_canary(UNUSED const struct slab_metadata *metadata, UNUSED void } #endif - memcpy((char *)p + size - canary_size, &metadata->canary_value, canary_size); + h_memcpy_real((char *)p + size - canary_size, &metadata->canary_value, canary_size); #endif } @@ -541,7 +541,7 @@ static void check_canary(UNUSED const struct slab_metadata *metadata, UNUSED con #endif u64 canary_value; - memcpy(&canary_value, (const char *)p + size - canary_size, canary_size); + h_memcpy_real(&canary_value, (const char *)p + size - canary_size, canary_size); #ifdef HAS_ARM_MTE if (unlikely(canary_value == 0)) { @@ -831,7 +831,7 @@ static inline void deallocate_small(void *p, const size_t *expected_size) { #endif if (ZERO_ON_FREE && !skip_zero) { - memset(p, 0, size - canary_size); + h_memset_real(p, 0, size - canary_size); } } @@ -1502,7 +1502,7 @@ EXPORT void *h_calloc(size_t nmemb, size_t size) { total_size = adjust_size_for_canary(total_size); void *p = alloc(total_size); if (!ZERO_ON_FREE && likely(p != NULL) && total_size && total_size <= max_slab_size_class) { - memset(p, 0, total_size - canary_size); + h_memset_real(p, 0, total_size - canary_size); } #ifdef HAS_ARM_MTE // use an assert instead of adding a conditional to memset() above (freed memory is always @@ -1624,7 +1624,7 @@ EXPORT void *h_realloc(void *old, size_t size) { mutex_unlock(&ra->lock); if (memory_remap_fixed(old, old_size, new, size)) { - memcpy(new, old, copy_size); + h_memcpy_real(new, old, copy_size); deallocate_pages(old, old_size, old_guard_size); } else { memory_unmap((char *)old - old_guard_size, old_guard_size); @@ -1646,7 +1646,7 @@ EXPORT void *h_realloc(void *old, size_t size) { if (copy_size > 0 && copy_size <= max_slab_size_class) { copy_size -= canary_size; } - memcpy(new, old_orig, copy_size); + h_memcpy_real(new, old_orig, copy_size); if (old_size <= max_slab_size_class) { deallocate_small(old, NULL); } else { @@ -1874,6 +1874,94 @@ EXPORT size_t h_malloc_object_size_fast(const void *p) { return SIZE_MAX; } +inline void *h_memcpy_real(void *dst, const void *src, size_t len) { +#if CONFIG_BLOCK_OPS_CHECK_SIZE && !defined(HAS_ARM_MTE) + char *p_dst = (char *)dst; + char const *p_src = (char const *)src; + + while(len--) { + *p_dst++ = *p_src++; + } + + return dst; +#else + return memcpy(dst, src, len); +#endif +} + +inline void *h_memmove_real(void *dst, const void *src, size_t len) { +#if CONFIG_BLOCK_OPS_CHECK_SIZE && !defined(HAS_ARM_MTE) + char *p_dst = (char *)dst; + char const *p_src = (char const *)src; + + if(p_src < p_dst) { + p_dst += len; + p_src += len; + while(len--) { + *--p_dst = *--p_src; + } + } else { + dst = h_memcpy_real(dst, src, len); + } + + return dst; +#else + return memmove(dst, src, len); +#endif +} + +inline void *h_memset_real(void *dst, int value, size_t len) { +#if CONFIG_BLOCK_OPS_CHECK_SIZE && !defined(HAS_ARM_MTE) + char *p_dst = (char *)dst; + + while(len--) { + *p_dst++ = value; + } + + return dst; +#else + return memset(dst, value, len); +#endif +} + +#if CONFIG_BLOCK_OPS_CHECK_SIZE && !defined(HAS_ARM_MTE) +EXPORT void *h_memcpy(void *dst, const void *src, size_t len) { + if(dst == src || len == 0) { + return dst; + } + if (len > malloc_object_size(src)) { + fatal_error("memcpy read overflow"); + } + if (len > malloc_object_size(dst)) { + fatal_error("memcpy buffer overflow"); + } + return h_memcpy_real(dst, src, len); +} + +EXPORT void *h_memmove(void *dst, const void *src, size_t len) { + if(dst == src || len == 0) { + return dst; + } + if (len > malloc_object_size(src)) { + fatal_error("memmove read overflow"); + } + if (len > malloc_object_size(dst)) { + fatal_error("memmove buffer overflow"); + } + return h_memmove_real(dst, src, len); +} + +EXPORT void *h_memset(void *dst, int value, size_t len) { + if(len == 0) { + return dst; + } + if (len > malloc_object_size(dst)) { + fatal_error("memset buffer overflow"); + } + return h_memset_real(dst, value, len); +} +#endif + EXPORT int h_mallopt(UNUSED int param, UNUSED int value) { #ifdef __ANDROID__ if (param == M_PURGE) { diff --git a/include/h_malloc.h b/include/h_malloc.h index 0eee395..f94a16e 100644 --- a/include/h_malloc.h +++ b/include/h_malloc.h @@ -15,6 +15,11 @@ extern "C" { #define h_realloc realloc #define h_aligned_alloc aligned_alloc #define h_free free +#if CONFIG_BLOCK_OPS_CHECK_SIZE && !defined(HAS_ARM_MTE) +#define h_memcpy memcpy +#define h_memmove memmove +//#define h_memset memset +#endif #define h_posix_memalign posix_memalign @@ -54,6 +59,14 @@ __attribute__((alloc_size(2))) void *h_realloc(void *ptr, size_t size); __attribute__((malloc)) __attribute__((alloc_size(2))) __attribute__((alloc_align(1))) void *h_aligned_alloc(size_t alignment, size_t size); void h_free(void *ptr); +void *h_memcpy_real(void *dst, const void *src, size_t len); +void *h_memmove_real(void *dst, const void *src, size_t len); +void *h_memset_real(void *dst, int value, size_t len); +#if CONFIG_BLOCK_OPS_CHECK_SIZE && !defined(HAS_ARM_MTE) +void *h_memcpy(void *dst, const void *src, size_t len); +void *h_memmove(void *dst, const void *src, size_t len); +void *h_memset(void *dst, int value, size_t len); +#endif // POSIX int h_posix_memalign(void **memptr, size_t alignment, size_t size); diff --git a/test/.gitignore b/test/.gitignore index d37a6a7..fa4fa1e 100644 --- a/test/.gitignore +++ b/test/.gitignore @@ -41,4 +41,15 @@ overflow_small_8_byte uninitialized_read_large uninitialized_read_small realloc_init +memcpy_buffer_overflow +memcpy_read_overflow +memcpy_valid_same +memcpy_valid_mismatched +memmove_buffer_overflow +memmove_read_overflow +memmove_valid_same +memmove_valid_mismatched +memset_buffer_overflow +memset_valid_same +memset_valid_mismatched __pycache__/ diff --git a/test/Makefile b/test/Makefile index 0eb3921..cd9e664 100644 --- a/test/Makefile +++ b/test/Makefile @@ -67,7 +67,18 @@ EXECUTABLES := \ invalid_malloc_object_size_small \ invalid_malloc_object_size_small_quarantine \ impossibly_large_malloc \ - realloc_init + realloc_init \ + memcpy_buffer_overflow \ + memcpy_read_overflow \ + memcpy_valid_same \ + memcpy_valid_mismatched \ + memmove_buffer_overflow \ + memmove_read_overflow \ + memmove_valid_same \ + memmove_valid_mismatched \ + memset_buffer_overflow \ + memset_valid_same \ + memset_valid_mismatched all: $(EXECUTABLES) diff --git a/test/memcpy_buffer_overflow.c b/test/memcpy_buffer_overflow.c new file mode 100644 index 0000000..16cab77 --- /dev/null +++ b/test/memcpy_buffer_overflow.c @@ -0,0 +1,15 @@ +#include +#include + +#include "test_util.h" + +OPTNONE int main(void) { + char *firstbuffer = malloc(16); + char *secondbuffer = malloc(32); + if (!firstbuffer && !secondbuffer) { + return 1; + } + memset(secondbuffer, 'a', 32); + memcpy(firstbuffer, secondbuffer, 32); + return 1; +} diff --git a/test/memcpy_read_overflow.c b/test/memcpy_read_overflow.c new file mode 100644 index 0000000..cf51498 --- /dev/null +++ b/test/memcpy_read_overflow.c @@ -0,0 +1,15 @@ +#include +#include + +#include "test_util.h" + +OPTNONE int main(void) { + char *firstbuffer = malloc(32); + char *secondbuffer = malloc(16); + if (!firstbuffer && !secondbuffer) { + return 1; + } + memset(secondbuffer, 'a', 16); + memcpy(firstbuffer, secondbuffer, 32); + return 1; +} diff --git a/test/memcpy_valid_mismatched.c b/test/memcpy_valid_mismatched.c new file mode 100644 index 0000000..81d718e --- /dev/null +++ b/test/memcpy_valid_mismatched.c @@ -0,0 +1,15 @@ +#include +#include + +#include "test_util.h" + +OPTNONE int main(void) { + char *firstbuffer = malloc(32); + char *secondbuffer = malloc(16); + if (!firstbuffer && !secondbuffer) { + return 1; + } + memset(secondbuffer, 'a', 16); + memcpy(firstbuffer, secondbuffer, 16); + return 0; +} diff --git a/test/memcpy_valid_same.c b/test/memcpy_valid_same.c new file mode 100644 index 0000000..1b408f0 --- /dev/null +++ b/test/memcpy_valid_same.c @@ -0,0 +1,15 @@ +#include +#include + +#include "test_util.h" + +OPTNONE int main(void) { + char *firstbuffer = malloc(16); + char *secondbuffer = malloc(16); + if (!firstbuffer && !secondbuffer) { + return 1; + } + memset(secondbuffer, 'a', 16); + memcpy(firstbuffer, secondbuffer, 16); + return 0; +} diff --git a/test/memmove_buffer_overflow.c b/test/memmove_buffer_overflow.c new file mode 100644 index 0000000..c83bf97 --- /dev/null +++ b/test/memmove_buffer_overflow.c @@ -0,0 +1,15 @@ +#include +#include + +#include "test_util.h" + +OPTNONE int main(void) { + char *firstbuffer = malloc(16); + char *secondbuffer = malloc(32); + if (!firstbuffer && !secondbuffer) { + return 1; + } + memset(secondbuffer, 'a', 32); + memmove(firstbuffer, secondbuffer, 32); + return 1; +} diff --git a/test/memmove_read_overflow.c b/test/memmove_read_overflow.c new file mode 100644 index 0000000..73e4509 --- /dev/null +++ b/test/memmove_read_overflow.c @@ -0,0 +1,15 @@ +#include +#include + +#include "test_util.h" + +OPTNONE int main(void) { + char *firstbuffer = malloc(32); + char *secondbuffer = malloc(16); + if (!firstbuffer && !secondbuffer) { + return 1; + } + memset(secondbuffer, 'a', 16); + memmove(firstbuffer, secondbuffer, 32); + return 1; +} diff --git a/test/memmove_valid_mismatched.c b/test/memmove_valid_mismatched.c new file mode 100644 index 0000000..5dd1bde --- /dev/null +++ b/test/memmove_valid_mismatched.c @@ -0,0 +1,15 @@ +#include +#include + +#include "test_util.h" + +OPTNONE int main(void) { + char *firstbuffer = malloc(32); + char *secondbuffer = malloc(16); + if (!firstbuffer && !secondbuffer) { + return 1; + } + memset(secondbuffer, 'a', 16); + memmove(firstbuffer, secondbuffer, 16); + return 0; +} diff --git a/test/memmove_valid_same.c b/test/memmove_valid_same.c new file mode 100644 index 0000000..2593abc --- /dev/null +++ b/test/memmove_valid_same.c @@ -0,0 +1,15 @@ +#include +#include + +#include "test_util.h" + +OPTNONE int main(void) { + char *firstbuffer = malloc(16); + char *secondbuffer = malloc(16); + if (!firstbuffer && !secondbuffer) { + return 1; + } + memset(secondbuffer, 'a', 16); + memmove(firstbuffer, secondbuffer, 16); + return 0; +} diff --git a/test/memset_buffer_overflow.c b/test/memset_buffer_overflow.c new file mode 100644 index 0000000..8f9e989 --- /dev/null +++ b/test/memset_buffer_overflow.c @@ -0,0 +1,13 @@ +#include +#include + +#include "test_util.h" + +OPTNONE int main(void) { + char *buffer = malloc(16); + if (!buffer) { + return 1; + } + memset(buffer, 'a', 32); + return 1; +} diff --git a/test/memset_valid_mismatched.c b/test/memset_valid_mismatched.c new file mode 100644 index 0000000..f57fef6 --- /dev/null +++ b/test/memset_valid_mismatched.c @@ -0,0 +1,13 @@ +#include +#include + +#include "test_util.h" + +OPTNONE int main(void) { + char *buffer = malloc(32); + if (!buffer) { + return 1; + } + memset(buffer, 'a', 16); + return 0; +} diff --git a/test/memset_valid_same.c b/test/memset_valid_same.c new file mode 100644 index 0000000..824c18f --- /dev/null +++ b/test/memset_valid_same.c @@ -0,0 +1,13 @@ +#include +#include + +#include "test_util.h" + +OPTNONE int main(void) { + char *buffer = malloc(16); + if (!buffer) { + return 1; + } + memset(buffer, 'a', 16); + return 0; +} diff --git a/test/test_smc.py b/test/test_smc.py index 170278e..88bb4e3 100644 --- a/test/test_smc.py +++ b/test/test_smc.py @@ -238,5 +238,70 @@ class TestSimpleMemoryCorruption(unittest.TestCase): "realloc_init") self.assertEqual(returncode, 0) + #def test_memcpy_buffer_overflow(self): + # _stdout, stderr, returncode = self.run_test( + # "memcpy_buffer_overflow") + # self.assertEqual(returncode, -6) + # self.assertEqual(stderr.decode( + # "utf-8"), "fatal allocator error: memcpy buffer overflow\n") + + #def test_memcpy_read_overflow(self): + # _stdout, stderr, returncode = self.run_test( + # "memcpy_read_overflow") + # self.assertEqual(returncode, -6) + # self.assertEqual(stderr.decode( + # "utf-8"), "fatal allocator error: memcpy read overflow\n") + + def test_memcpy_valid_same(self): + _stdout, _stderr, returncode = self.run_test( + "memcpy_valid_same") + self.assertEqual(returncode, 0) + + def test_memcpy_valid_mismatched(self): + _stdout, _stderr, returncode = self.run_test( + "memcpy_valid_mismatched") + self.assertEqual(returncode, 0) + + #def test_memmove_buffer_overflow(self): + # _stdout, stderr, returncode = self.run_test( + # "memmove_buffer_overflow") + # self.assertEqual(returncode, -6) + # self.assertEqual(stderr.decode( + # "utf-8"), "fatal allocator error: memmove buffer overflow\n") + + #def test_memmove_read_overflow(self): + # _stdout, stderr, returncode = self.run_test( + # "memmove_read_overflow") + # self.assertEqual(returncode, -6) + # self.assertEqual(stderr.decode( + # "utf-8"), "fatal allocator error: memmove read overflow\n") + + def test_memmove_valid_same(self): + _stdout, _stderr, returncode = self.run_test( + "memmove_valid_same") + self.assertEqual(returncode, 0) + + def test_memmove_valid_mismatched(self): + _stdout, _stderr, returncode = self.run_test( + "memmove_valid_mismatched") + self.assertEqual(returncode, 0) + + #def test_memset_buffer_overflow(self): + # _stdout, stderr, returncode = self.run_test( + # "memset_buffer_overflow") + # self.assertEqual(returncode, -6) + # self.assertEqual(stderr.decode( + # "utf-8"), "fatal allocator error: memset buffer overflow\n") + + def test_memset_valid_same(self): + _stdout, _stderr, returncode = self.run_test( + "memset_valid_same") + self.assertEqual(returncode, 0) + + def test_memset_valid_mismatched(self): + _stdout, _stderr, returncode = self.run_test( + "memset_valid_mismatched") + self.assertEqual(returncode, 0) + if __name__ == '__main__': unittest.main()