commit 707c1e2e263fd34f70a5f780e77820d667ba2931 Author: Andrea Shepard <andrea@torproject.org> Date: Thu Feb 6 14:47:34 2014 -0800 NULL out conns on tlschans when freeing in case channel_run_cleanup() is late; fixes bug 9602 --- changes/bug9602 | 4 + src/or/channeltls.c | 193 +++++++++++++++++++++++++++++++----------------- src/or/connection.c | 16 ++++ src/or/connection_or.c | 5 ++ 4 files changed, 149 insertions(+), 69 deletions(-) diff --git a/changes/bug9602 b/changes/bug9602 new file mode 100644 index 0000000..9e9a3ca --- /dev/null +++ b/changes/bug9602 @@ -0,0 +1,4 @@ + o Bugfixes + - Null out orconn->chan->conn when closing orconn in case orconn is freed + before channel_run_cleanup() gets to orconn->chan, and handle the null + conn edge case correctly in channel_tls_t methods. Fixes bug #9602. diff --git a/src/or/channeltls.c b/src/or/channeltls.c index f751c0d..495f856 100644 --- a/src/or/channeltls.c +++ b/src/or/channeltls.c @@ -365,7 +365,7 @@ channel_tls_describe_transport_method(channel_t *chan) tor_assert(chan); - tlschan = BASE_CHAN_TO_TLS(chan); + tlschan = BASE_CHAN_TO_TLS(chan); if (tlschan->conn) { id = TO_CONN(tlschan->conn)->global_identifier; @@ -394,15 +394,18 @@ channel_tls_describe_transport_method(channel_t *chan) static int channel_tls_get_remote_addr_method(channel_t *chan, tor_addr_t *addr_out) { + int rv = 0; channel_tls_t *tlschan = BASE_CHAN_TO_TLS(chan); tor_assert(tlschan); tor_assert(addr_out); - tor_assert(tlschan->conn); - tor_addr_copy(addr_out, &(TO_CONN(tlschan->conn)->addr)); + if (tlschan->conn) { + tor_addr_copy(addr_out, &(TO_CONN(tlschan->conn)->addr)); + rv = 1; + } else tor_addr_make_unspec(addr_out); - return 1; + return rv; } /** @@ -426,41 +429,43 @@ channel_tls_get_remote_descr_method(channel_t *chan, int flags) char *addr_str; tor_assert(tlschan); - tor_assert(tlschan->conn); - - conn = TO_CONN(tlschan->conn); - switch (flags) { - case 0: - /* Canonical address with port*/ - tor_snprintf(buf, MAX_DESCR_LEN + 1, - "%s:%u", conn->address, conn->port); - answer = buf; - break; - case GRD_FLAG_ORIGINAL: - /* Actual address with port */ - addr_str = tor_dup_addr(&(tlschan->conn->real_addr)); - tor_snprintf(buf, MAX_DESCR_LEN + 1, - "%s:%u", addr_str, conn->port); - tor_free(addr_str); - answer = buf; - break; - case GRD_FLAG_ADDR_ONLY: - /* Canonical address, no port */ - strlcpy(buf, conn->address, sizeof(buf)); - answer = buf; - break; - case GRD_FLAG_ORIGINAL|GRD_FLAG_ADDR_ONLY: - /* Actual address, no port */ - addr_str = tor_dup_addr(&(tlschan->conn->real_addr)); - strlcpy(buf, addr_str, sizeof(buf)); - tor_free(addr_str); - answer = buf; - break; - - default: - /* Something's broken in channel.c */ - tor_assert(1); + if (tlschan->conn) { + conn = TO_CONN(tlschan->conn); + switch (flags) { + case 0: + /* Canonical address with port*/ + tor_snprintf(buf, MAX_DESCR_LEN + 1, + "%s:%u", conn->address, conn->port); + answer = buf; + break; + case GRD_FLAG_ORIGINAL: + /* Actual address with port */ + addr_str = tor_dup_addr(&(tlschan->conn->real_addr)); + tor_snprintf(buf, MAX_DESCR_LEN + 1, + "%s:%u", addr_str, conn->port); + tor_free(addr_str); + answer = buf; + break; + case GRD_FLAG_ADDR_ONLY: + /* Canonical address, no port */ + strlcpy(buf, conn->address, sizeof(buf)); + answer = buf; + break; + case GRD_FLAG_ORIGINAL|GRD_FLAG_ADDR_ONLY: + /* Actual address, no port */ + addr_str = tor_dup_addr(&(tlschan->conn->real_addr)); + strlcpy(buf, addr_str, sizeof(buf)); + tor_free(addr_str); + answer = buf; + break; + default: + /* Something's broken in channel.c */ + tor_assert(1); + } + } else { + strlcpy(buf, "(No connection)", sizeof(buf)); + answer = buf; } return answer; @@ -480,9 +485,16 @@ channel_tls_has_queued_writes_method(channel_t *chan) channel_tls_t *tlschan = BASE_CHAN_TO_TLS(chan); tor_assert(tlschan); - tor_assert(tlschan->conn); + if (!(tlschan->conn)) { + log_info(LD_CHANNEL, + "something called has_queued_writes on a tlschan " + "(%p with ID " U64_FORMAT " but no conn", + chan, U64_PRINTF_ARG(chan->global_identifier)); + } - outbuf_len = connection_get_outbuf_len(TO_CONN(tlschan->conn)); + outbuf_len = (tlschan->conn != NULL) ? + connection_get_outbuf_len(TO_CONN(tlschan->conn)) : + 0; return (outbuf_len > 0); } @@ -502,24 +514,26 @@ channel_tls_is_canonical_method(channel_t *chan, int req) channel_tls_t *tlschan = BASE_CHAN_TO_TLS(chan); tor_assert(tlschan); - tor_assert(tlschan->conn); - switch (req) { - case 0: - answer = tlschan->conn->is_canonical; - break; - case 1: - /* - * Is the is_canonical bit reliable? In protocols version 2 and up - * we get the canonical address from a NETINFO cell, but in older - * versions it might be based on an obsolete descriptor. - */ - answer = (tlschan->conn->link_proto >= 2); - break; - default: - /* This shouldn't happen; channel.c is broken if it does */ - tor_assert(1); + if (tlschan->conn) { + switch (req) { + case 0: + answer = tlschan->conn->is_canonical; + break; + case 1: + /* + * Is the is_canonical bit reliable? In protocols version 2 and up + * we get the canonical address from a NETINFO cell, but in older + * versions it might be based on an obsolete descriptor. + */ + answer = (tlschan->conn->link_proto >= 2); + break; + default: + /* This shouldn't happen; channel.c is broken if it does */ + tor_assert(1); + } } + /* else return 0 for tlschan->conn == NULL */ return answer; } @@ -540,6 +554,15 @@ channel_tls_matches_extend_info_method(channel_t *chan, tor_assert(tlschan); tor_assert(extend_info); + /* Never match if we have no conn */ + if (!(tlschan->conn)) { + log_info(LD_CHANNEL, + "something called matches_extend_info on a tlschan " + "(%p with ID " U64_FORMAT " but no conn", + chan, U64_PRINTF_ARG(chan->global_identifier)); + return 0; + } + return (tor_addr_eq(&(extend_info->addr), &(TO_CONN(tlschan->conn)->addr)) && (extend_info->port == TO_CONN(tlschan->conn)->port)); @@ -561,7 +584,15 @@ channel_tls_matches_target_method(channel_t *chan, tor_assert(tlschan); tor_assert(target); - tor_assert(tlschan->conn); + + /* Never match if we have no conn */ + if (!(tlschan->conn)) { + log_info(LD_CHANNEL, + "something called matches_target on a tlschan " + "(%p with ID " U64_FORMAT " but no conn", + chan, U64_PRINTF_ARG(chan->global_identifier)); + return 0; + } return tor_addr_eq(&(tlschan->conn->real_addr), target); } @@ -577,14 +608,22 @@ static int channel_tls_write_cell_method(channel_t *chan, cell_t *cell) { channel_tls_t *tlschan = BASE_CHAN_TO_TLS(chan); + int written = 0; tor_assert(tlschan); tor_assert(cell); - tor_assert(tlschan->conn); - connection_or_write_cell_to_buf(cell, tlschan->conn); + if (tlschan->conn) { + connection_or_write_cell_to_buf(cell, tlschan->conn); + ++written; + } else { + log_info(LD_CHANNEL, + "something called write_cell on a tlschan " + "(%p with ID " U64_FORMAT " but no conn", + chan, U64_PRINTF_ARG(chan->global_identifier)); + } - return 1; + return written; } /** @@ -600,18 +639,26 @@ channel_tls_write_packed_cell_method(channel_t *chan, { channel_tls_t *tlschan = BASE_CHAN_TO_TLS(chan); size_t cell_network_size = get_cell_network_size(chan->wide_circ_ids); + int written = 0; tor_assert(tlschan); tor_assert(packed_cell); - tor_assert(tlschan->conn); - connection_write_to_buf(packed_cell->body, cell_network_size, - TO_CONN(tlschan->conn)); + if (tlschan->conn) { + connection_write_to_buf(packed_cell->body, cell_network_size, + TO_CONN(tlschan->conn)); - /* This is where the cell is finished; used to be done from relay.c */ - packed_cell_free(packed_cell); + /* This is where the cell is finished; used to be done from relay.c */ + packed_cell_free(packed_cell); + ++written; + } else { + log_info(LD_CHANNEL, + "something called write_packed_cell on a tlschan " + "(%p with ID " U64_FORMAT " but no conn", + chan, U64_PRINTF_ARG(chan->global_identifier)); + } - return 1; + return written; } /** @@ -625,14 +672,22 @@ static int channel_tls_write_var_cell_method(channel_t *chan, var_cell_t *var_cell) { channel_tls_t *tlschan = BASE_CHAN_TO_TLS(chan); + int written = 0; tor_assert(tlschan); tor_assert(var_cell); - tor_assert(tlschan->conn); - connection_or_write_var_cell_to_buf(var_cell, tlschan->conn); + if (tlschan->conn) { + connection_or_write_var_cell_to_buf(var_cell, tlschan->conn); + ++written; + } else { + log_info(LD_CHANNEL, + "something called write_var_cell on a tlschan " + "(%p with ID " U64_FORMAT " but no conn", + chan, U64_PRINTF_ARG(chan->global_identifier)); + } - return 1; + return written; } /************************************************* diff --git a/src/or/connection.c b/src/or/connection.c index 062c971..4f74a1d 100644 --- a/src/or/connection.c +++ b/src/or/connection.c @@ -514,6 +514,22 @@ connection_free_(connection_t *conn) or_handshake_state_free(or_conn->handshake_state); or_conn->handshake_state = NULL; tor_free(or_conn->nickname); + if (or_conn->chan) { + /* Owww, this shouldn't happen, but... */ + log_info(LD_CHANNEL, + "Freeing orconn at %p, saw channel %p with ID " + U64_FORMAT " left un-NULLed", + or_conn, TLS_CHAN_TO_BASE(or_conn->chan), + U64_PRINTF_ARG( + TLS_CHAN_TO_BASE(or_conn->chan)->global_identifier)); + if (!(TLS_CHAN_TO_BASE(or_conn->chan)->state == CHANNEL_STATE_CLOSED || + TLS_CHAN_TO_BASE(or_conn->chan)->state == CHANNEL_STATE_ERROR)) { + channel_close_for_error(TLS_CHAN_TO_BASE(or_conn->chan)); + } + + or_conn->chan->conn = NULL; + or_conn->chan = NULL; + } } if (conn->type == CONN_TYPE_AP) { entry_connection_t *entry_conn = TO_ENTRY_CONN(conn); diff --git a/src/or/connection_or.c b/src/or/connection_or.c index 3d16e14..8e7cd9e 100644 --- a/src/or/connection_or.c +++ b/src/or/connection_or.c @@ -622,6 +622,11 @@ connection_or_about_to_close(or_connection_t *or_conn) /* Tell the controlling channel we're closed */ if (or_conn->chan) { channel_closed(TLS_CHAN_TO_BASE(or_conn->chan)); + /* + * NULL this out because the channel might hang around a little + * longer before channel_run_cleanup() gets it. + */ + or_conn->chan->conn = NULL; or_conn->chan = NULL; }