From 5fafe74f373438f6f8514c2040dbfb6b62263d8f Mon Sep 17 00:00:00 2001 From: Julien Rische Date: Thu, 23 Jun 2022 14:42:22 +0200 Subject: [PATCH] Fix libkrad client cleanup code Resolves: rhbz#2100351 Signed-off-by: Julien Rische --- krb5-krad-remote.patch | 171 +++++++++++++++++++++++++++++++++++++++++ krb5.spec | 7 +- 2 files changed, 177 insertions(+), 1 deletion(-) create mode 100644 krb5-krad-remote.patch diff --git a/krb5-krad-remote.patch b/krb5-krad-remote.patch new file mode 100644 index 0000000..b5b071f --- /dev/null +++ b/krb5-krad-remote.patch @@ -0,0 +1,171 @@ +From a8551b609fd50458ca3c06a9dd345b6cdf18689b Mon Sep 17 00:00:00 2001 +From: Greg Hudson +Date: Tue, 9 Nov 2021 13:00:43 -0500 +Subject: [PATCH 1/2] Avoid use after free during libkrad cleanup + +libkrad client requests contain a list of references to remotes, with +no back-references or reference counts. To prevent accesses to +dangling references during cleanup, cancel all requests on all remotes +before freeing any remotes. + +Remove the code for aging out unused servers. This code was fairly +safe as all requests referencing a remote should have completed or +timed out during an hour of disuse, but in the current design we have +no way to guarantee or check that. The set of addresses we send +RADIUS requests to will generally be small, so aging out servers is +unnecessary. + +ticket: 9035 (new) +--- + src/lib/krad/client.c | 42 ++++++++++++++--------------------------- + src/lib/krad/internal.h | 4 ++++ + src/lib/krad/remote.c | 11 ++++++++--- + 3 files changed, 26 insertions(+), 31 deletions(-) + +diff --git a/src/lib/krad/client.c b/src/lib/krad/client.c +index 6365dd1c6..810940afc 100644 +--- a/src/lib/krad/client.c ++++ b/src/lib/krad/client.c +@@ -64,7 +64,6 @@ struct request_st { + + struct server_st { + krad_remote *serv; +- time_t last; + K5_LIST_ENTRY(server_st) list; + }; + +@@ -81,15 +80,10 @@ get_server(krad_client *rc, const struct addrinfo *ai, const char *secret, + krad_remote **out) + { + krb5_error_code retval; +- time_t currtime; + server *srv; + +- if (time(&currtime) == (time_t)-1) +- return errno; +- + K5_LIST_FOREACH(srv, &rc->servers, list) { + if (kr_remote_equals(srv->serv, ai, secret)) { +- srv->last = currtime; + *out = srv->serv; + return 0; + } +@@ -98,7 +92,6 @@ get_server(krad_client *rc, const struct addrinfo *ai, const char *secret, + srv = calloc(1, sizeof(server)); + if (srv == NULL) + return ENOMEM; +- srv->last = currtime; + + retval = kr_remote_new(rc->kctx, rc->vctx, ai, secret, &srv->serv); + if (retval != 0) { +@@ -173,28 +166,12 @@ request_new(krad_client *rc, krad_code code, const krad_attrset *attrs, + return 0; + } + +-/* Close remotes that haven't been used in a while. */ +-static void +-age(struct server_head *head, time_t currtime) +-{ +- server *srv, *tmp; +- +- K5_LIST_FOREACH_SAFE(srv, head, list, tmp) { +- if (currtime == (time_t)-1 || currtime - srv->last > 60 * 60) { +- K5_LIST_REMOVE(srv, list); +- kr_remote_free(srv->serv); +- free(srv); +- } +- } +-} +- + /* Handle a response from a server (or related errors). */ + static void + on_response(krb5_error_code retval, const krad_packet *reqp, + const krad_packet *rspp, void *data) + { + request *req = data; +- time_t currtime; + size_t i; + + /* Do nothing if we are already completed. */ +@@ -221,10 +198,6 @@ on_response(krb5_error_code retval, const krad_packet *reqp, + for (i = 0; req->remotes[i].remote != NULL; i++) + kr_remote_cancel(req->remotes[i].remote, req->remotes[i].packet); + +- /* Age out servers that haven't been used in a while. */ +- if (time(&currtime) != (time_t)-1) +- age(&req->rc->servers, currtime); +- + request_free(req); + } + +@@ -247,10 +220,23 @@ krad_client_new(krb5_context kctx, verto_ctx *vctx, krad_client **out) + void + krad_client_free(krad_client *rc) + { ++ server *srv; ++ + if (rc == NULL) + return; + +- age(&rc->servers, -1); ++ /* Cancel all requests before freeing any remotes, since each request's ++ * callback data may contain references to multiple remotes. */ ++ K5_LIST_FOREACH(srv, &rc->servers, list) ++ kr_remote_cancel_all(srv->serv); ++ ++ while (!K5_LIST_EMPTY(&rc->servers)) { ++ srv = K5_LIST_FIRST(&rc->servers); ++ K5_LIST_REMOVE(srv, list); ++ kr_remote_free(srv->serv); ++ free(srv); ++ } ++ + free(rc); + } + +diff --git a/src/lib/krad/internal.h b/src/lib/krad/internal.h +index 223ffd730..fa012db78 100644 +--- a/src/lib/krad/internal.h ++++ b/src/lib/krad/internal.h +@@ -120,6 +120,10 @@ kr_remote_send(krad_remote *rr, krad_code code, krad_attrset *attrs, + void + kr_remote_cancel(krad_remote *rr, const krad_packet *pkt); + ++/* Cancel all requests awaiting responses. */ ++void ++kr_remote_cancel_all(krad_remote *rr); ++ + /* Determine if this remote object refers to the remote resource identified + * by the addrinfo struct and the secret. */ + krb5_boolean +diff --git a/src/lib/krad/remote.c b/src/lib/krad/remote.c +index c8912892c..01a5fd2a4 100644 +--- a/src/lib/krad/remote.c ++++ b/src/lib/krad/remote.c +@@ -452,15 +452,20 @@ error: + return retval; + } + ++void ++kr_remote_cancel_all(krad_remote *rr) ++{ ++ while (!K5_TAILQ_EMPTY(&rr->list)) ++ request_finish(K5_TAILQ_FIRST(&rr->list), ECANCELED, NULL); ++} ++ + void + kr_remote_free(krad_remote *rr) + { + if (rr == NULL) + return; + +- while (!K5_TAILQ_EMPTY(&rr->list)) +- request_finish(K5_TAILQ_FIRST(&rr->list), ECANCELED, NULL); +- ++ kr_remote_cancel_all(rr); + free(rr->secret); + if (rr->info != NULL) + free(rr->info->ai_addr); +-- +2.35.3 + diff --git a/krb5.spec b/krb5.spec index 9d8db78..7e9025a 100644 --- a/krb5.spec +++ b/krb5.spec @@ -42,7 +42,7 @@ Summary: The Kerberos network authentication system Name: krb5 Version: 1.19.1 -Release: %{?zdpd}20%{?dist} +Release: %{?zdpd}21%{?dist} # rharwood has trust path to signing key and verifies on check-in Source0: https://web.mit.edu/kerberos/dist/krb5/%{version}/krb5-%{version}%{?dashpre}.tar.gz @@ -95,6 +95,7 @@ Patch30: downstream-Use-newly-enforced-dejagnu-path-naming-convention.patch Patch31: Try-harder-to-avoid-password-change-replay-errors.patch Patch32: Add-configure-variable-for-default-PKCS-11-module.patch Patch33: downstream-Allow-krad-UDP-TCP-localhost-connection-with-FIPS.patch +Patch34: krb5-krad-remote.patch License: MIT URL: https://web.mit.edu/kerberos/www/ @@ -652,6 +653,10 @@ exit 0 %{_libdir}/libkadm5srv_mit.so.* %changelog +* Thu Jun 23 2022 Julien Rische - 1.19.1-21 +- Fix libkrad client cleanup +- Resolves: rhbz#2100351 + * Thu May 12 2022 Julien Rische - 1.19.1-20 - Fix OpenSSL 3 MD5 encyption in FIPS mode - Allow libkrad UDP/TCP connection to localhost in FIPS mode