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| author | Tomas Krizek <tomas.krizek@nic.cz> | 2021-05-03 11:55:03 +0200 |
|---|---|---|
| committer | Tomas Krizek <tomas.krizek@nic.cz> | 2021-05-03 11:55:03 +0200 |
| commit | fa42b4aeffb552c6a8d648c7f658f9f40c9d3558 (patch) | |
| tree | 3856c19f1f28473adeca7ace5b1f2d17d71840d6 | |
| parent | Merge !1171: ci: utilize test reports (diff) | |
| parent | validator: avoid assertion in an edge-case (diff) | |
| download | knot-resolver-fa42b4aeffb552c6a8d648c7f658f9f40c9d3558.tar.xz knot-resolver-fa42b4aeffb552c6a8d648c7f658f9f40c9d3558.zip | |
Merge branch 'nsec3-iters-downgrade-2' into 'master'
validator: avoid assertion in an edge-case
See merge request knot/knot-resolver!1169
| -rw-r--r-- | NEWS | 5 | ||||
| -rw-r--r-- | lib/dnssec/nsec3.c | 7 | ||||
| -rw-r--r-- | lib/dnssec/nsec3.h | 1 | ||||
| -rw-r--r-- | lib/layer/validate.c | 3 | ||||
| m--------- | tests/integration/deckard | 0 |
5 files changed, 15 insertions, 1 deletions
@@ -1,6 +1,11 @@ Knot Resolver 5.3.2 (2021-0m-dd) ================================ +Security +-------- +- validator: fix 5.3.1 regression on over-limit NSEC3 edge case (!1169) + Assertion might be triggered by query/answer, potentially DoS. + Improvements ------------ - cache: improve handling write errors from LMDB (!1159) diff --git a/lib/dnssec/nsec3.c b/lib/dnssec/nsec3.c index e9e536a3..f3a48c06 100644 --- a/lib/dnssec/nsec3.c +++ b/lib/dnssec/nsec3.c @@ -596,6 +596,13 @@ int kr_nsec3_wildcard_answer_response_check(const knot_pkt_t *pkt, knot_section_ if (rrset->type != KNOT_RRTYPE_NSEC3) { continue; } + if (knot_nsec3_iters(rrset->rrs.rdata) > KR_NSEC3_MAX_ITERATIONS) { + /* Avoid hashing with too many iterations. + * If we get here, the `sname` wildcard probably ends up bogus, + * but it gets downgraded to KR_RANK_INSECURE when validator + * gets to verifying one of these over-limit NSEC3 RRs. */ + continue; + } int ret = covers_name(&flags, rrset, sname); if (ret != 0) { return ret; diff --git a/lib/dnssec/nsec3.h b/lib/dnssec/nsec3.h index 1e316f56..0fdbfcef 100644 --- a/lib/dnssec/nsec3.h +++ b/lib/dnssec/nsec3.h @@ -39,6 +39,7 @@ int kr_nsec3_name_error_response_check(const knot_pkt_t *pkt, knot_section_t sec * KNOT_ERANGE - NSEC3 RR that covers a wildcard * has been found, but has opt-out flag set; * otherwise - error. + * Records over KR_NSEC3_MAX_ITERATIONS are skipped, so you probably get kr_error(ENOENT). */ int kr_nsec3_wildcard_answer_response_check(const knot_pkt_t *pkt, knot_section_t section_id, const knot_dname_t *sname, int trim_to_next); diff --git a/lib/layer/validate.c b/lib/layer/validate.c index cf5dda2d..cf5c88a1 100644 --- a/lib/layer/validate.c +++ b/lib/layer/validate.c @@ -894,7 +894,8 @@ static void rank_records(struct kr_query *qry, bool any_rank, enum kr_rank rank_ bailiwick) < 0) { continue; } - if (kr_rank_test(entry->rank, KR_RANK_INITIAL) + if (any_rank + || kr_rank_test(entry->rank, KR_RANK_INITIAL) || kr_rank_test(entry->rank, KR_RANK_TRY) || kr_rank_test(entry->rank, KR_RANK_MISSING)) { kr_rank_set(&entry->rank, rank_to_set); diff --git a/tests/integration/deckard b/tests/integration/deckard -Subproject 01eabd23dc3315ef9d27ae7f5fe19c142dcbdfd +Subproject c4628156e6cf499e8052c321b24793a176ded49 |