commit de5f0d8ba7156e9579cc52898cbe0b3a25f64aad Author: Nick Mathewson nickm@torproject.org Date: Wed Jun 28 14:21:21 2017 -0400

Replace crash on missing handle in consdiffmgr with nonfatal assert

Attempts to mitigate 22752. --- src/or/consdiffmgr.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/or/consdiffmgr.c b/src/or/consdiffmgr.c index 4036f66..638fcd6 100644 --- a/src/or/consdiffmgr.c +++ b/src/or/consdiffmgr.c @@ -325,7 +325,8 @@ cdm_diff_ht_purge(consensus_flavor_t flav, if ((*diff)->cdm_diff_status == CDM_DIFF_PRESENT && flav == (*diff)->flavor) {

- if (consensus_cache_entry_handle_get((*diff)->entry) == NULL) { + if (BUG((*diff)->entry == NULL) || + consensus_cache_entry_handle_get((*diff)->entry) == NULL) { /* the underlying entry has gone away; drop this. */ next = HT_NEXT_RMV(cdm_diff_ht, &cdm_diff_ht, diff); cdm_diff_free(this); @@ -622,6 +623,9 @@ consdiffmgr_find_diff_from(consensus_cache_entry_t **entry_out, return CONSDIFF_IN_PROGRESS; }

+ if (BUG(ent->entry == NULL)) { + return CONSDIFF_NOT_FOUND; + } *entry_out = consensus_cache_entry_handle_get(ent->entry); return (*entry_out) ? CONSDIFF_AVAILABLE : CONSDIFF_NOT_FOUND;