CA2022: Avoid inexact read with Stream.Read

Property	Value
Rule ID	CA2022
Title	Avoid inexact read with Stream.Read
Category	Reliability
Fix is breaking or non-breaking	Non-breaking
Enabled by default in .NET 9	As warning

Cause

A call to Stream.Read or Stream.ReadAsync is made and the return value isn't checked.

Rule description

Stream.Read and Stream.ReadAsync might return fewer bytes than requested, resulting in unreliable code if the return value isn't checked.

How to fix violations

To fix a violation, either check the return value (which is the total number of bytes read into the buffer) or call Stream.ReadExactly or Stream.ReadExactlyAsync instead.

Example

The following code snippet shows a violation of CA2022 and the fix for the violation.

C#‎

void M1(Stream stream, byte[] buffer)
{
    // CA2022 violation.
    stream.Read(buffer, 0, buffer.Length);

    // Fix for the violation.
    stream.ReadExactly(buffer);
}

When to suppress warnings

You shouldn't suppress warnings from this rule, as your app might hang if you don't fix the violations.

See also

• Partial and zero-byte reads in DeflateStream, GZipStream, and CryptoStream