fix: proper fd lifecycle management to eliminate fdsan crash#877
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Root cause: The DLT_CONNECTION_GATEWAY connections share a receiver pointer aliased into DltGatewayConnection.client.receiver. When dlt_connection_destroy() closed the fd, the gateway's client.sock retained the stale fd number. If the kernel reused that fd number (e.g., for a FILE*), subsequent gateway send() calls would trigger Android fdsan abort. Changes: - dlt_connection_destroy: Do NOT close fd for GATEWAY connections (they don't own it). Only detach the receiver pointer. - dlt_gateway_close_connection: New function that properly closes client.sock AND invalidates client.receiver.fd at all disconnect points. - Deferred destruction: Connections are now marked PENDING_DESTROY instead of being freed immediately. A sweep phase after the event loop iteration safely destroys them, preventing use-after-free when callbacks trigger their own connection's removal. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Signed-off-by: Pierre Tardy <pierre.tardy@renault.com>
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fdsan crash is found while integrating dlt-daemon into an android automotive system.
We are not deep experts of the dlt-daemon inner working, but I think that the IA answer is sound.
We could not reproduce the fdsan crash after patch applied.
Root cause: The DLT_CONNECTION_GATEWAY connections share a receiver pointer aliased into DltGatewayConnection.client.receiver. When dlt_connection_destroy() closed the fd, the gateway's client.sock retained the stale fd number. If the kernel reused that fd number (e.g., for a FILE*), subsequent gateway send() calls would trigger Android fdsan abort.
Changes: