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From 4e2e1ea0908d7e6ad7f38ae04fdcdf2411f8b942 Mon Sep 17 00:00:00 2001
From: Michal Sekletar <msekleta@redhat.com>
Date: Wed, 27 Nov 2024 18:07:32 +0100
Subject: [PATCH] core/wide-area: fix for CVE-2024-52615
CVE: CVE-2024-52615
Upstream-Status: Backport [https://github.com/avahi/avahi/commit/4e2e1ea0908d7e6ad7f38ae04fdcdf2411f8b942]
Signed-off-by: Zhang Peng <peng.zhang1.cn@windriver.com>
---
avahi-core/wide-area.c | 128 ++++++++++++++++++++++-------------------
1 file changed, 69 insertions(+), 59 deletions(-)
diff --git a/avahi-core/wide-area.c b/avahi-core/wide-area.c
index 00a15056e..06df7afc6 100644
--- a/avahi-core/wide-area.c
+++ b/avahi-core/wide-area.c
@@ -81,6 +81,10 @@ struct AvahiWideAreaLookup {
AvahiAddress dns_server_used;
+ int fd;
+ AvahiWatch *watch;
+ AvahiProtocol proto;
+
AVAHI_LLIST_FIELDS(AvahiWideAreaLookup, lookups);
AVAHI_LLIST_FIELDS(AvahiWideAreaLookup, by_key);
};
@@ -88,9 +92,6 @@ struct AvahiWideAreaLookup {
struct AvahiWideAreaLookupEngine {
AvahiServer *server;
- int fd_ipv4, fd_ipv6;
- AvahiWatch *watch_ipv4, *watch_ipv6;
-
/* Cache */
AVAHI_LLIST_HEAD(AvahiWideAreaCacheEntry, cache);
AvahiHashmap *cache_by_key;
@@ -125,35 +126,67 @@ static AvahiWideAreaLookup* find_lookup(AvahiWideAreaLookupEngine *e, uint16_t i
return l;
}
+static void socket_event(AVAHI_GCC_UNUSED AvahiWatch *w, int fd, AVAHI_GCC_UNUSED AvahiWatchEvent events, void *userdata);
+
static int send_to_dns_server(AvahiWideAreaLookup *l, AvahiDnsPacket *p) {
+ AvahiWideAreaLookupEngine *e;
AvahiAddress *a;
+ AvahiServer *s;
+ AvahiWatch *w;
+ int r;
assert(l);
assert(p);
- if (l->engine->n_dns_servers <= 0)
+ e = l->engine;
+ assert(e);
+
+ s = e->server;
+ assert(s);
+
+ if (e->n_dns_servers <= 0)
return -1;
- assert(l->engine->current_dns_server < l->engine->n_dns_servers);
+ assert(e->current_dns_server < e->n_dns_servers);
- a = &l->engine->dns_servers[l->engine->current_dns_server];
+ a = &e->dns_servers[e->current_dns_server];
l->dns_server_used = *a;
- if (a->proto == AVAHI_PROTO_INET) {
+ if (l->fd >= 0) {
+ /* We are reusing lookup object and sending packet to another server so let's cleanup before we establish connection to new server. */
+ s->poll_api->watch_free(l->watch);
+ l->watch = NULL;
- if (l->engine->fd_ipv4 < 0)
- return -1;
+ close(l->fd);
+ l->fd = -EBADF;
+ }
- return avahi_send_dns_packet_ipv4(l->engine->fd_ipv4, AVAHI_IF_UNSPEC, p, NULL, &a->data.ipv4, AVAHI_DNS_PORT);
+ assert(a->proto == AVAHI_PROTO_INET || a->proto == AVAHI_PROTO_INET6);
- } else {
- assert(a->proto == AVAHI_PROTO_INET6);
+ if (a->proto == AVAHI_PROTO_INET)
+ r = s->config.use_ipv4 ? avahi_open_unicast_socket_ipv4() : -1;
+ else
+ r = s->config.use_ipv6 ? avahi_open_unicast_socket_ipv6() : -1;
- if (l->engine->fd_ipv6 < 0)
- return -1;
+ if (r < 0) {
+ avahi_log_error(__FILE__ ": Failed to create socket for wide area lookup");
+ return -1;
+ }
- return avahi_send_dns_packet_ipv6(l->engine->fd_ipv6, AVAHI_IF_UNSPEC, p, NULL, &a->data.ipv6, AVAHI_DNS_PORT);
+ w = s->poll_api->watch_new(s->poll_api, r, AVAHI_WATCH_IN, socket_event, l);
+ if (!w) {
+ close(r);
+ avahi_log_error(__FILE__ ": Failed to create socket watch for wide area lookup");
+ return -1;
}
+
+ l->fd = r;
+ l->watch = w;
+ l->proto = a->proto;
+
+ return a->proto == AVAHI_PROTO_INET ?
+ avahi_send_dns_packet_ipv4(l->fd, AVAHI_IF_UNSPEC, p, NULL, &a->data.ipv4, AVAHI_DNS_PORT):
+ avahi_send_dns_packet_ipv6(l->fd, AVAHI_IF_UNSPEC, p, NULL, &a->data.ipv6, AVAHI_DNS_PORT);
}
static void next_dns_server(AvahiWideAreaLookupEngine *e) {
@@ -246,6 +279,9 @@ AvahiWideAreaLookup *avahi_wide_area_lookup_new(
l->dead = 0;
l->key = avahi_key_ref(key);
l->cname_key = avahi_key_new_cname(l->key);
+ l->fd = -EBADF;
+ l->watch = NULL;
+ l->proto = AVAHI_PROTO_UNSPEC;
l->callback = callback;
l->userdata = userdata;
@@ -314,6 +350,12 @@ static void lookup_destroy(AvahiWideAreaLookup *l) {
if (l->cname_key)
avahi_key_unref(l->cname_key);
+ if (l->watch)
+ l->engine->server->poll_api->watch_free(l->watch);
+
+ if (l->fd >= 0)
+ close(l->fd);
+
avahi_free(l);
}
@@ -572,14 +614,20 @@ static void handle_packet(AvahiWideAreaLookupEngine *e, AvahiDnsPacket *p) {
}
static void socket_event(AVAHI_GCC_UNUSED AvahiWatch *w, int fd, AVAHI_GCC_UNUSED AvahiWatchEvent events, void *userdata) {
- AvahiWideAreaLookupEngine *e = userdata;
+ AvahiWideAreaLookup *l = userdata;
+ AvahiWideAreaLookupEngine *e = l->engine;
AvahiDnsPacket *p = NULL;
- if (fd == e->fd_ipv4)
- p = avahi_recv_dns_packet_ipv4(e->fd_ipv4, NULL, NULL, NULL, NULL, NULL);
+ assert(l);
+ assert(e);
+ assert(l->fd == fd);
+
+ if (l->proto == AVAHI_PROTO_INET)
+ p = avahi_recv_dns_packet_ipv4(l->fd, NULL, NULL, NULL, NULL, NULL);
else {
- assert(fd == e->fd_ipv6);
- p = avahi_recv_dns_packet_ipv6(e->fd_ipv6, NULL, NULL, NULL, NULL, NULL);
+ assert(l->proto == AVAHI_PROTO_INET6);
+
+ p = avahi_recv_dns_packet_ipv6(l->fd, NULL, NULL, NULL, NULL, NULL);
}
if (p) {
@@ -598,32 +646,6 @@ AvahiWideAreaLookupEngine *avahi_wide_area_engine_new(AvahiServer *s) {
e->server = s;
e->cleanup_dead = 0;
- /* Create sockets */
- e->fd_ipv4 = s->config.use_ipv4 ? avahi_open_unicast_socket_ipv4() : -1;
- e->fd_ipv6 = s->config.use_ipv6 ? avahi_open_unicast_socket_ipv6() : -1;
-
- if (e->fd_ipv4 < 0 && e->fd_ipv6 < 0) {
- avahi_log_error(__FILE__": Failed to create wide area sockets: %s", strerror(errno));
-
- if (e->fd_ipv6 >= 0)
- close(e->fd_ipv6);
-
- if (e->fd_ipv4 >= 0)
- close(e->fd_ipv4);
-
- avahi_free(e);
- return NULL;
- }
-
- /* Create watches */
-
- e->watch_ipv4 = e->watch_ipv6 = NULL;
-
- if (e->fd_ipv4 >= 0)
- e->watch_ipv4 = s->poll_api->watch_new(e->server->poll_api, e->fd_ipv4, AVAHI_WATCH_IN, socket_event, e);
- if (e->fd_ipv6 >= 0)
- e->watch_ipv6 = s->poll_api->watch_new(e->server->poll_api, e->fd_ipv6, AVAHI_WATCH_IN, socket_event, e);
-
e->n_dns_servers = e->current_dns_server = 0;
/* Initialize cache */
@@ -651,18 +673,6 @@ void avahi_wide_area_engine_free(AvahiWideAreaLookupEngine *e) {
avahi_hashmap_free(e->lookups_by_id);
avahi_hashmap_free(e->lookups_by_key);
- if (e->watch_ipv4)
- e->server->poll_api->watch_free(e->watch_ipv4);
-
- if (e->watch_ipv6)
- e->server->poll_api->watch_free(e->watch_ipv6);
-
- if (e->fd_ipv6 >= 0)
- close(e->fd_ipv6);
-
- if (e->fd_ipv4 >= 0)
- close(e->fd_ipv4);
-
avahi_free(e);
}
@@ -680,7 +690,7 @@ void avahi_wide_area_set_servers(AvahiWideAreaLookupEngine *e, const AvahiAddres
if (a) {
for (e->n_dns_servers = 0; n > 0 && e->n_dns_servers < AVAHI_WIDE_AREA_SERVERS_MAX; a++, n--)
- if ((a->proto == AVAHI_PROTO_INET && e->fd_ipv4 >= 0) || (a->proto == AVAHI_PROTO_INET6 && e->fd_ipv6 >= 0))
+ if (a->proto == AVAHI_PROTO_INET || a->proto == AVAHI_PROTO_INET6)
e->dns_servers[e->n_dns_servers++] = *a;
} else {
assert(n == 0);
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