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author | MarcoFalke <falke.marco@gmail.com> | 2022-03-10 10:08:43 +0100 |
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committer | MarcoFalke <falke.marco@gmail.com> | 2022-03-10 10:24:05 +0100 |
commit | 5e33620ad81363d817a0050f29c68e4c3cf594b5 (patch) | |
tree | b593c7687e20ffff3d842a960ef644eb19a1dca4 /src/util | |
parent | 430acb7d2a3272977d5a66bf9a09bcd55ffd15cc (diff) | |
parent | a84650ebd5ac2cbb49f14eb7c98736a3f8215bf1 (diff) | |
download | bitcoin-5e33620ad81363d817a0050f29c68e4c3cf594b5.tar.xz |
Merge bitcoin/bitcoin#24371: util: Fix `ReadBinaryFile` reading beyond maxsize
a84650ebd5ac2cbb49f14eb7c98736a3f8215bf1 util: Fix ReadBinaryFile reading beyond maxsize (klementtan)
Pull request description:
Currently `ReadBinaryFile` will read beyond `maxsize` if `maxsize` is not a multiple of `128` (size of buffer)
This is due to `fread` being called with `count = 128` instead of `count = min(128, maxsize - retval.size()` at every iteration
The following unit test will fail:
```cpp
BOOST_AUTO_TEST_CASE(util_ReadWriteFile)
{
fs::path tmpfolder = m_args.GetDataDirBase();
fs::path tmpfile = tmpfolder / "read_binary.dat";
std::string expected_text(300,'c');
{
std::ofstream file{tmpfile};
file << expected_text;
}
{
// read half the contents in file
auto [valid, text] = ReadBinaryFile(tmpfile, expected_text.size() / 2);
BOOST_CHECK_EQUAL(text.size(), 150);
}
}
```
Error:
```
test/util_tests.cpp:2593: error: in "util_tests/util_ReadWriteFile": check text.size() == 150 has failed [256 != 150]
```
ACKs for top commit:
laanwj:
Code review ACK a84650ebd5ac2cbb49f14eb7c98736a3f8215bf1
theStack:
Code-review ACK a84650ebd5ac2cbb49f14eb7c98736a3f8215bf1
Tree-SHA512: 752eebe58bc2102dec199b6775f8c3304d899f0ce36d6a022a58e27b076ba945ccd572858b19137b769effd8c6de73a9277f641be24dfb17657fb7173ea0eda0
Diffstat (limited to 'src/util')
-rw-r--r-- | src/util/readwritefile.cpp | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/src/util/readwritefile.cpp b/src/util/readwritefile.cpp index a45c41d367..628e6a3980 100644 --- a/src/util/readwritefile.cpp +++ b/src/util/readwritefile.cpp @@ -18,7 +18,7 @@ std::pair<bool,std::string> ReadBinaryFile(const fs::path &filename, size_t maxs std::string retval; char buffer[128]; do { - const size_t n = fread(buffer, 1, sizeof(buffer), f); + const size_t n = fread(buffer, 1, std::min(sizeof(buffer), maxsize - retval.size()), f); // Check for reading errors so we don't return any data if we couldn't // read the entire file (or up to maxsize) if (ferror(f)) { @@ -26,7 +26,7 @@ std::pair<bool,std::string> ReadBinaryFile(const fs::path &filename, size_t maxs return std::make_pair(false,""); } retval.append(buffer, buffer+n); - } while (!feof(f) && retval.size() <= maxsize); + } while (!feof(f) && retval.size() < maxsize); fclose(f); return std::make_pair(true,retval); } |