Concurrent read and dispose zlib race condition

[alinpahontu2912]

Description

A race condition exists between inflate operations and disposal. Inflater synchronizes reads with SyncLock, but Dispose() is not synchronized, allowing the underlying zlib state to be released while an inflate call is in progress, leading to possible crashes.

Reproduction Steps

Attempt multiple Read and Dispose operations on the same DeflateStream.

Expected behavior

Dispose should not be able to release the native inflater state while an inflate call is in progress.

Actual behavior

Concurrent Read and Dispose can result in invalid native state being used during decompression.

Regression?

No response

Known Workarounds

No response

Configuration

No response

Other information

No response

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[teo-tsirpanis]

Do you have a repro? We use SafeHandle to wrap ZStream* values, which means that if the handle is Disposed while being used, releasing the native resources will be deferred until all uses of the handle conclude.