Validate IOBuf capacity at construction time

Summary: Add a CHECK() to the IOBuf constructor to ensure the underlying buffer does not include any bytes that have been poisoned by AddressSanitizer.

Reviewed By: yfeldblum

Differential Revision: D25627483

fbshipit-source-id: 5bca59e545c32ba7b61430d7cd4787712eecb204

folly/io/IOBuf.cpp

@@ -34,6 +34,7 @@
 #include <folly/lang/Align.h>
 #include <folly/lang/Exception.h>
 #include <folly/memory/Malloc.h>
+#include <folly/memory/SanitizeAddress.h>
 
 using std::unique_ptr;
 
@@ -498,6 +499,8 @@ IOBuf::IOBuf(
       flagsAndSharedInfo_(flagsAndSharedInfo) {
   assert(data >= buf);
   assert(data + length <= buf + capacity);
+
+  CHECK(!folly::asan_region_is_poisoned(buf, capacity));
 }
 
 IOBuf::~IOBuf() {

folly/io/test/IOBufTest.cpp

@@ -244,6 +244,17 @@ TEST(IOBuf, WrapBuffer) {
   EXPECT_EQ(size4, iobuf4.length());
   EXPECT_EQ(buf4.get(), iobuf4.buffer());
   EXPECT_EQ(size4, iobuf4.capacity());
+
+  if (folly::kIsSanitizeAddress) {
+    const uint32_t size5 = 100;
+    uint8_t buf5[size5];
+    EXPECT_DEATH(IOBuf::wrapBuffer(buf5, size5 + 1), "asan_region_is_poisoned");
+
+    const uint32_t size6 = 100;
+    std::vector<uint8_t> buf6(size6);
+    EXPECT_DEATH(
+        IOBuf::wrapBuffer(buf6.data(), size6 + 1), "asan_region_is_poisoned");
+  }
 }
 
 TEST(IOBuf, CreateCombined) {