Make sure EventPipe streaming thread won't write session->streaming_thread after session free. #58615
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…hread after session free. In case where ep_disable is called by a different thread (close IPC command) there was a race between streaming threads setting session->streaming_thread to NULL and IPC command triggering a call to disable_holding_lock and freeing session. Resetting the streaming_thread in streaming thread must happens before it signals its shutdown event to prevent the race.
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//CC @josalem |
josalem
approved these changes
Sep 3, 2021
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We should try to backport this change to release/6.0 for rc2. |
Yes, I fixed another incarnation of this issue in an error case I hit locally where we wrote to memory after free on the same thread, #53886 but missed that the same scenario might be hit when the streaming thread is racing with IPC stop tracing command on different thread. |
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/backport to release/6.0 |
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Started backporting to release/6.0: https://github.com/dotnet/runtime/actions/runs/1204902529 |
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In case where
ep_disableis called by a different thread (stop tracing IPC command) there was a race between streaming thread settingsession->streaming_threadtoNULLand IPC command triggering a call todisable_holding_lockand freeing session.Resetting the
session->streaming_threadin streaming thread must happens before it signals its shutdown event to prevent the race causing heap corruption, writing NULL into freed memory.Probably root cause of #57461.