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net: tcp: Fix deadlock with tcp_conn_close()

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While improving thread safety of the TCP stack I've introduced a
possible deadlock scenario, when calling tcp_conn_close() in tcp_in().
This function shall not be called with connection mutex locked, as it
calls registered recv callback internally, which could lead to deadlock
between TCP/socket mutexes.

This commit moves the tcp_conn_close() back where it was originally
called. I've verified that the thread safety is still solid with the
test apps used originally.

Signed-off-by: Robert Lubos <robert.lubos@nordicsemi.no>
This commit is contained in:
Robert Lubos 2023-12-11 16:49:55 +01:00 committed by Carles Cufí
parent e268a6ce7d
commit 6b00b537aa
1 changed files with 8 additions and 6 deletions
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14
subsys/net/ip/tcp.c
View file

@ -3392,12 +3392,7 @@ out:
goto next_state;
}
/* Make sure we close the connection only once by checking connection
* state.
*/
if (do_close && conn->state != TCP_UNUSED && conn->state != TCP_CLOSED) {
tcp_conn_close(conn, close_status);
} else if (conn->context) {
if (conn->context) {
/* If the conn->context is not set, then the connection was
* already closed.
*/
@ -3423,6 +3418,13 @@ out:
}
}
/* Make sure we close the connection only once by checking connection
* state.
*/
if (do_close && conn->state != TCP_UNUSED && conn->state != TCP_CLOSED) {
tcp_conn_close(conn, close_status);
}
return verdict;
}