diff options
author | Yifan Hong <elsk@google.com> | 2018-05-11 14:19:42 -0700 |
---|---|---|
committer | android-build-team Robot <android-build-team-robot@google.com> | 2018-06-04 23:54:03 +0000 |
commit | ef8f161086684440c6f32f1faf2344618da89d2c (patch) | |
tree | 3307c0fd2951f5fc6ee32575c55c35814a89a270 | |
parent | 6e933f63a9f3722a315420759bb667f8637b8a84 (diff) | |
download | libhidl-ef8f161086684440c6f32f1faf2344618da89d2c.tar.gz |
mapMemory: Do not map if size is > SIZE_MAX
Bug: 79376389
Test: hidl_test
Test: POC in bug
Change-Id: Ibaced858aa07bfd7ab6e938cc1339b974b0de14f
Merged-In: Ibaced858aa07bfd7ab6e938cc1339b974b0de14f
(cherry picked from commit 694bd8d1b43b9e60623cb3d5bd3f21662680dd7c)
-rw-r--r-- | libhidlmemory/mapping.cpp | 10 | ||||
-rw-r--r-- | transport/memory/1.0/default/Android.bp | 1 | ||||
-rw-r--r-- | transport/memory/1.0/default/AshmemMapper.cpp | 13 |
3 files changed, 24 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/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) { |