Commit 90528741 authored by Nick Mathewson's avatar Nick Mathewson 👁
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Avoid attempts to double-remove edge connections from the DNS resolver.

Also, avoid crashing when we attempt to double-remove an edge
connection from the DNS resolver: just log a bug warning instead.

Fixes bug 14129.  Bugfix on 0d20fee2, which was in 0.0.7rc1.

jowr found the bug.  cypherpunks wrote the fix.  I added the log
message and removed the assert.
parent dca902ce
o Major bugfixes (exit node stability):
- Fix an assertion failure that could occur under high DNS load. Fixes
bug 14129; bugfix on Tor 0.0.7rc1. Found by "jowr"; diagnosed and fixed
by "cypherpunks".
...@@ -557,6 +557,8 @@ purge_expired_resolves(time_t now) ...@@ -557,6 +557,8 @@ purge_expired_resolves(time_t now)
/* Connections should only be pending if they have no socket. */ /* Connections should only be pending if they have no socket. */
tor_assert(!SOCKET_OK(pend->conn->base_.s)); tor_assert(!SOCKET_OK(pend->conn->base_.s));
pendconn = pend->conn; pendconn = pend->conn;
/* Prevent double-remove */
pendconn->base_.state = EXIT_CONN_STATE_RESOLVEFAILED;
if (!pendconn->base_.marked_for_close) { if (!pendconn->base_.marked_for_close) {
connection_edge_end(pendconn, END_STREAM_REASON_TIMEOUT); connection_edge_end(pendconn, END_STREAM_REASON_TIMEOUT);
circuit_detach_stream(circuit_get_by_edge_conn(pendconn), pendconn); circuit_detach_stream(circuit_get_by_edge_conn(pendconn), pendconn);
...@@ -1132,7 +1134,9 @@ connection_dns_remove(edge_connection_t *conn) ...@@ -1132,7 +1134,9 @@ connection_dns_remove(edge_connection_t *conn)
return; /* more are pending */ return; /* more are pending */
} }
} }
tor_assert(0); /* not reachable unless onlyconn not in pending list */ log_warn(LD_BUG, "Connection (fd "TOR_SOCKET_T_FORMAT") was not waiting "
"for a resolve of %s, but we tried to remove it.",
conn->base_.s, escaped_safe_str(conn->base_.address));
} }
} }
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