commit cec616a0c8ff060cb722e54342fd30aeab3ad285 Author: David Goulet <dgoulet@torproject.org> Date: Tue Dec 4 14:27:46 2018 -0500 hs-v3: Don't BUG() if descriptor is found on SOCKS connection retry When retrying all SOCKS connection because new directory information just arrived, do not BUG() if a connection in state AP_CONN_STATE_RENDDESC_WAIT is found to have a usable descriptor. There is a rare case when this can happen as detailed in #28669 so the right thing to do is put that connection back in circuit wait state so the descriptor can be retried. Fixes #28669 Signed-off-by: David Goulet <dgoulet@torproject.org> --- changes/ticket28669 | 6 ++++++ src/feature/hs/hs_client.c | 19 +++++++++++++------ 2 files changed, 19 insertions(+), 6 deletions(-) diff --git a/changes/ticket28669 b/changes/ticket28669 new file mode 100644 index 000000000..32c6114ff --- /dev/null +++ b/changes/ticket28669 @@ -0,0 +1,6 @@ + o Minor bugfix (hidden service v3, client): + - Avoid a BUG() stacktrace in case a SOCKS connection is found waiting for + the descriptor while we do have it in the cache. There is a rare case + when this can happen. Now, tor will recover and retry the descriptor. + Fixes bug 28669; bugfix on 0.3.2.4-alpha. + diff --git a/src/feature/hs/hs_client.c b/src/feature/hs/hs_client.c index 22aacdfe9..5fded92fe 100644 --- a/src/feature/hs/hs_client.c +++ b/src/feature/hs/hs_client.c @@ -296,12 +296,19 @@ retry_all_socks_conn_waiting_for_desc(void) /* Order a refetch in case it works this time. */ status = hs_client_refetch_hsdesc(&edge_conn->hs_ident->identity_pk); - if (BUG(status == HS_CLIENT_FETCH_HAVE_DESC)) { - /* This case is unique because it can NOT happen in theory. Once we get - * a new descriptor, the HS client subsystem is notified immediately and - * the connections waiting for it are handled which means the state will - * change from renddesc wait state. Log this and continue to next - * connection. */ + if (status == HS_CLIENT_FETCH_HAVE_DESC) { + /* This is a rare case where a SOCKS connection is in state waiting for + * a descriptor but we do have it in the cache. + * + * This can happen is tor comes back from suspend where it previously + * had the descriptor but the intro points were not usuable. Once it + * came back to life, the intro point failure cache was cleaned up and + * thus the descriptor became usable again leaving us in this code path. + * + * We'll mark the connection as waiting for a circuit so the descriptor + * can be retried. This is safe because a connection in state waiting + * for a descriptor can not be in the entry connection pending list. */ + mark_conn_as_waiting_for_circuit(base_conn, approx_time()); continue; } /* In the case of an error, either all SOCKS connections have been