From e0a963355715acfba797056e7b916d6492c6e41a Mon Sep 17 00:00:00 2001
From: Doyle <doylet@protonmail.com>
Date: Tue, 19 May 2020 18:45:32 +1000
Subject: [PATCH] ByteSlice: Fix persisting ptr to std::moved SSO buffer
The Bug:
1. Construct `byte_slice.portion_` with `epee::span(buffer)` which copies a pointer to the SSO buffer to `byte_slice.portion_`
2. It constructs `byte_slice.storage_` with `std::move(buffer)` (normally this swap pointers, but SSO means a memcpy and clear on the original SSO buffer)
3. `slice.data()` returns a pointer from `slice.portion_` that points to the original SSO cleared buffer, `slice.storage_` has the actual string.
---
contrib/epee/src/byte_slice.cpp | 5 ++++-
tests/unit_tests/epee_utils.cpp | 23 +++++++++++++++++++++++
2 files changed, 27 insertions(+), 1 deletion(-)
diff --git a/contrib/epee/src/byte_slice.cpp b/contrib/epee/src/byte_slice.cpp
index 12cc83e6c..faf7689be 100644
--- a/contrib/epee/src/byte_slice.cpp
+++ b/contrib/epee/src/byte_slice.cpp
@@ -133,10 +133,13 @@ namespace epee
template<typename T>
byte_slice::byte_slice(const adapt_buffer, T&& buffer)
- : storage_(nullptr), portion_(to_byte_span(to_span(buffer)))
+ : storage_(nullptr), portion_(nullptr)
{
if (!buffer.empty())
+ {
storage_ = allocate_slice<adapted_byte_slice<T>>(0, std::move(buffer));
+ portion_ = to_byte_span(to_span(static_cast<adapted_byte_slice<T> *>(storage_.get())->buffer));
+ }
}
byte_slice::byte_slice(std::initializer_list<span<const std::uint8_t>> sources)
diff --git a/tests/unit_tests/epee_utils.cpp b/tests/unit_tests/epee_utils.cpp
index a2cec965e..0f91671a7 100644
--- a/tests/unit_tests/epee_utils.cpp
+++ b/tests/unit_tests/epee_utils.cpp
@@ -387,6 +387,29 @@ TEST(ByteSlice, Construction)
EXPECT_FALSE(std::is_copy_assignable<epee::byte_slice>());
}
+TEST(ByteSlice, DataReturnedMatches)
+{
+ for (int i = 64; i > 0; i--)
+ {
+ std::string sso_string(i, 'a');
+ std::string original = sso_string;
+ epee::byte_slice slice{std::move(sso_string)};
+
+ EXPECT_EQ(slice.size(), original.size());
+ EXPECT_EQ(memcmp(slice.data(), original.data(), original.size()), 0);
+ }
+
+ for (int i = 64; i > 0; i--)
+ {
+ std::vector<uint8_t> sso_vector(i, 'a');
+ std::vector<uint8_t> original = sso_vector;
+ epee::byte_slice slice{std::move(sso_vector)};
+
+ EXPECT_EQ(slice.size(), original.size());
+ EXPECT_EQ(memcmp(slice.data(), original.data(), original.size()), 0);
+ }
+}
+
TEST(ByteSlice, NoExcept)
{
EXPECT_TRUE(std::is_nothrow_default_constructible<epee::byte_slice>());