diff options
| -rw-r--r-- | libhidlmemory/mapping.cpp | 10 | ||||
| -rw-r--r-- | transport/HidlBinderSupport.cpp | 10 | ||||
| -rw-r--r-- | transport/memory/1.0/default/Android.bp | 1 | ||||
| -rw-r--r-- | transport/memory/1.0/default/AshmemMapper.cpp | 13 |
4 files changed, 34 insertions, 0 deletions
diff --git a/libhidlmemory/mapping.cpp b/libhidlmemory/mapping.cpp index 3cb6485..8f0bcf4 100644 --- a/libhidlmemory/mapping.cpp +++ b/libhidlmemory/mapping.cpp @@ -24,6 +24,7 @@ #include <android-base/logging.h> #include <android/hidl/memory/1.0/IMapper.h> #include <hidl/HidlSupport.h> +#include <log/log.h> using android::sp; using android::hidl::memory::V1_0::IMemory; @@ -63,6 +64,15 @@ sp<IMemory> mapMemory(const hidl_memory& memory) { return nullptr; } + // hidl_memory's size is stored in uint64_t, but mapMemory's mmap will map + // size in size_t. If size is over SIZE_MAX, mapMemory could succeed + // but the mapped memory's actual size will be smaller than the reported size. + if (memory.size() > SIZE_MAX) { + LOG(ERROR) << "Cannot map " << memory.size() << " bytes of memory because it is too large."; + android_errorWriteLog(0x534e4554, "79376389"); + return nullptr; + } + Return<sp<IMemory>> ret = mapper->mapMemory(memory); if (!ret.isOk()) { diff --git a/transport/HidlBinderSupport.cpp b/transport/HidlBinderSupport.cpp index fe1ccbc..31e3be8 100644 --- a/transport/HidlBinderSupport.cpp +++ b/transport/HidlBinderSupport.cpp @@ -19,6 +19,7 @@ #include <hidl/HidlBinderSupport.h> // C includes +#include <inttypes.h> #include <unistd.h> // C++ includes @@ -66,6 +67,15 @@ status_t readEmbeddedFromParcel(const hidl_memory& memory, parentOffset + hidl_memory::kOffsetOfName); } + // hidl_memory's size is stored in uint64_t, but mapMemory's mmap will map + // size in size_t. If size is over SIZE_MAX, mapMemory could succeed + // but the mapped memory's actual size will be smaller than the reported size. + if (memory.size() > SIZE_MAX) { + ALOGE("Cannot use memory with %" PRId64 " bytes because it is too large.", memory.size()); + android_errorWriteLog(0x534e4554, "79376389"); + return BAD_VALUE; + } + return _hidl_err; } diff --git a/transport/memory/1.0/default/Android.bp b/transport/memory/1.0/default/Android.bp index a4f45cf..470d3b8 100644 --- a/transport/memory/1.0/default/Android.bp +++ b/transport/memory/1.0/default/Android.bp @@ -32,6 +32,7 @@ cc_library_shared { "libhardware", "libhwbinder", "libbase", + "liblog", "libutils", "libhidlbase", "libhidltransport", diff --git a/transport/memory/1.0/default/AshmemMapper.cpp b/transport/memory/1.0/default/AshmemMapper.cpp index bef4767..cefaaa4 100644 --- a/transport/memory/1.0/default/AshmemMapper.cpp +++ b/transport/memory/1.0/default/AshmemMapper.cpp @@ -16,6 +16,9 @@ #include "AshmemMapper.h" +#include <inttypes.h> + +#include <log/log.h> #include <sys/mman.h> #include "AshmemMemory.h" @@ -32,6 +35,16 @@ Return<sp<IMemory>> AshmemMapper::mapMemory(const hidl_memory& mem) { return nullptr; } + // If ashmem service runs in 32-bit (size_t is uint32_t) and a 64-bit + // client process requests a memory > 2^32 bytes, the size would be + // converted to a 32-bit number in mmap. mmap could succeed but the + // mapped memory's actual size would be smaller than the reported size. + if (mem.size() > SIZE_MAX) { + ALOGE("Cannot map %" PRIu64 " bytes of memory because it is too large.", mem.size()); + android_errorWriteLog(0x534e4554, "79376389"); + return nullptr; + } + int fd = mem.handle()->data[0]; void* data = mmap(0, mem.size(), PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0); if (data == MAP_FAILED) { |