diff --git a/SPECS/avahi/CVE-2026-34933.patch b/SPECS/avahi/CVE-2026-34933.patch new file mode 100644 index 00000000000..1e5871c29d5 --- /dev/null +++ b/SPECS/avahi/CVE-2026-34933.patch @@ -0,0 +1,211 @@ +From 3e454de4577863d88b1da97e37dba22e37d138b5 Mon Sep 17 00:00:00 2001 +From: Evgeny Vereshchagin +Date: Wed, 1 Apr 2026 05:31:58 +0000 +Subject: [PATCH 1/3] core: refuse to accept publish flags where both wide_area + and multicast are set + +It fixes a bug where it was possible for unprivileged local users to +crash avahi-daemon via D-Bus by calling EntryGroup methods accepting +flags and passing both AVAHI_PUBLISH_USE_WIDE_AREA and +AVAHI_PUBLISH_USE_MULTICAST there. For example when AddRecord was +invoked like that avahi-daemon crashed with +``` +dbus-entry-group.c: interface=org.freedesktop.Avahi.EntryGroup, path=/Client0/EntryGroup1, member=AddRecord +avahi-daemon: entry.c:57: transport_flags_from_domain: Assertion `!((*flags & AVAHI_PUBLISH_USE_MULTICAST) && (*flags & AVAHI_PUBLISH_USE_WIDE_AREA))' failed. +==84944== +==84944== Process terminating with default action of signal 6 (SIGABRT) +==84944== at 0x4B353BC: __pthread_kill_implementation (pthread_kill.c:44) +==84944== by 0x4ADE941: raise (raise.c:26) +==84944== by 0x4AC64AB: abort (abort.c:77) +==84944== by 0x4AC641F: __assert_fail_base.cold (assert.c:118) +==84944== by 0x48A9404: transport_flags_from_domain (entry.c:57) +==84944== by 0x48A9F8F: server_add_internal (entry.c:224) +==84944== by 0x48AA49F: avahi_server_add (entry.c:324) +==84944== by 0x401A670: avahi_dbus_msg_entry_group_impl (dbus-entry-group.c:348) +==84944== by 0x4A70741: ??? (in /usr/lib/x86_64-linux-gnu/libdbus-1.so.3.38.3) +==84944== by 0x4A5FB22: dbus_connection_dispatch (in /usr/lib/x86_64-linux-gnu/libdbus-1.so.3.38.3) +==84944== by 0x401D01D: dispatch_timeout_callback (dbus-watch-glue.c:105) +==84944== by 0x488E3AE: timeout_callback (simple-watch.c:447) +==84944== +``` +It's a follow-up to fbce111b069aa1e4c701ed37ee1d9f6d6cefaac5 where +those flags were introduced and consistent with the other places +where wide_area/multicast flags are used. + +It was discovered by +Guillaume Meunier - Head of Vulnerability Operations Center France - Orange Cyberdefense + +https://github.com/avahi/avahi/security/advisories/GHSA-w65r-6gxh-vhvc + +CVE-2026-34933 +Upstream-reference: https://patch-diff.githubusercontent.com/raw/avahi/avahi/pull/891.patch +--- + avahi-core/entry.c | 7 +++++++ + 1 file changed, 7 insertions(+) + +diff --git a/avahi-core/entry.c b/avahi-core/entry.c +index 0d86213..06eb120 100644 +--- a/avahi-core/entry.c ++++ b/avahi-core/entry.c +@@ -207,6 +207,7 @@ static AvahiEntry * server_add_internal( + AVAHI_PUBLISH_UPDATE| + AVAHI_PUBLISH_USE_WIDE_AREA| + AVAHI_PUBLISH_USE_MULTICAST), AVAHI_ERR_INVALID_FLAGS); ++ AVAHI_CHECK_VALIDITY_RETURN_NULL(s, !(flags & AVAHI_PUBLISH_USE_WIDE_AREA) || !(flags & AVAHI_PUBLISH_USE_MULTICAST), AVAHI_ERR_INVALID_FLAGS); + AVAHI_CHECK_VALIDITY_RETURN_NULL(s, avahi_is_valid_domain_name(r->key->name), AVAHI_ERR_INVALID_HOST_NAME); + AVAHI_CHECK_VALIDITY_RETURN_NULL(s, r->ttl != 0, AVAHI_ERR_INVALID_TTL); + AVAHI_CHECK_VALIDITY_RETURN_NULL(s, !avahi_key_is_pattern(r->key), AVAHI_ERR_IS_PATTERN); +@@ -454,6 +455,7 @@ int avahi_server_add_address( + AVAHI_PUBLISH_UPDATE| + AVAHI_PUBLISH_USE_WIDE_AREA| + AVAHI_PUBLISH_USE_MULTICAST), AVAHI_ERR_INVALID_FLAGS); ++ AVAHI_CHECK_VALIDITY(s, !(flags & AVAHI_PUBLISH_USE_WIDE_AREA) || !(flags & AVAHI_PUBLISH_USE_MULTICAST), AVAHI_ERR_INVALID_FLAGS); + AVAHI_CHECK_VALIDITY(s, !name || avahi_is_valid_fqdn(name), AVAHI_ERR_INVALID_HOST_NAME); + + /* Prepare the host naem */ +@@ -595,6 +597,7 @@ static int server_add_service_strlst_nocopy( + AVAHI_PUBLISH_UPDATE| + AVAHI_PUBLISH_USE_WIDE_AREA| + AVAHI_PUBLISH_USE_MULTICAST), AVAHI_ERR_INVALID_FLAGS); ++ AVAHI_CHECK_VALIDITY_SET_RET_GOTO_FAIL(s, !(flags & AVAHI_PUBLISH_USE_WIDE_AREA) || !(flags & AVAHI_PUBLISH_USE_MULTICAST), AVAHI_ERR_INVALID_FLAGS); + AVAHI_CHECK_VALIDITY_SET_RET_GOTO_FAIL(s, avahi_is_valid_service_name(name), AVAHI_ERR_INVALID_SERVICE_NAME); + AVAHI_CHECK_VALIDITY_SET_RET_GOTO_FAIL(s, avahi_is_valid_service_type_strict(type), AVAHI_ERR_INVALID_SERVICE_TYPE); + AVAHI_CHECK_VALIDITY_SET_RET_GOTO_FAIL(s, !domain || avahi_is_valid_domain_name(domain), AVAHI_ERR_INVALID_DOMAIN_NAME); +@@ -754,6 +757,7 @@ static int server_update_service_txt_strlst_nocopy( + AVAHI_PUBLISH_NO_COOKIE| + AVAHI_PUBLISH_USE_WIDE_AREA| + AVAHI_PUBLISH_USE_MULTICAST), AVAHI_ERR_INVALID_FLAGS); ++ AVAHI_CHECK_VALIDITY_SET_RET_GOTO_FAIL(s, !(flags & AVAHI_PUBLISH_USE_WIDE_AREA) || !(flags & AVAHI_PUBLISH_USE_MULTICAST), AVAHI_ERR_INVALID_FLAGS); + AVAHI_CHECK_VALIDITY_SET_RET_GOTO_FAIL(s, avahi_is_valid_service_name(name), AVAHI_ERR_INVALID_SERVICE_NAME); + AVAHI_CHECK_VALIDITY_SET_RET_GOTO_FAIL(s, avahi_is_valid_service_type_strict(type), AVAHI_ERR_INVALID_SERVICE_TYPE); + AVAHI_CHECK_VALIDITY_SET_RET_GOTO_FAIL(s, !domain || avahi_is_valid_domain_name(domain), AVAHI_ERR_INVALID_DOMAIN_NAME); +@@ -843,6 +847,7 @@ int avahi_server_add_service_subtype( + AVAHI_CHECK_VALIDITY_SET_RET_GOTO_FAIL(s, AVAHI_IF_VALID(interface), AVAHI_ERR_INVALID_INTERFACE); + AVAHI_CHECK_VALIDITY_SET_RET_GOTO_FAIL(s, AVAHI_PROTO_VALID(protocol), AVAHI_ERR_INVALID_PROTOCOL); + AVAHI_CHECK_VALIDITY_SET_RET_GOTO_FAIL(s, AVAHI_FLAGS_VALID(flags, AVAHI_PUBLISH_USE_MULTICAST|AVAHI_PUBLISH_USE_WIDE_AREA), AVAHI_ERR_INVALID_FLAGS); ++ AVAHI_CHECK_VALIDITY_SET_RET_GOTO_FAIL(s, !(flags & AVAHI_PUBLISH_USE_WIDE_AREA) || !(flags & AVAHI_PUBLISH_USE_MULTICAST), AVAHI_ERR_INVALID_FLAGS); + AVAHI_CHECK_VALIDITY_SET_RET_GOTO_FAIL(s, avahi_is_valid_service_name(name), AVAHI_ERR_INVALID_SERVICE_NAME); + AVAHI_CHECK_VALIDITY_SET_RET_GOTO_FAIL(s, avahi_is_valid_service_type_strict(type), AVAHI_ERR_INVALID_SERVICE_TYPE); + AVAHI_CHECK_VALIDITY_SET_RET_GOTO_FAIL(s, !domain || avahi_is_valid_domain_name(domain), AVAHI_ERR_INVALID_DOMAIN_NAME); +@@ -910,6 +915,7 @@ static AvahiEntry *server_add_dns_server_name( + assert(name); + + AVAHI_CHECK_VALIDITY_RETURN_NULL(s, AVAHI_FLAGS_VALID(flags, AVAHI_PUBLISH_USE_WIDE_AREA|AVAHI_PUBLISH_USE_MULTICAST), AVAHI_ERR_INVALID_FLAGS); ++ AVAHI_CHECK_VALIDITY_RETURN_NULL(s, !(flags & AVAHI_PUBLISH_USE_WIDE_AREA) || !(flags & AVAHI_PUBLISH_USE_MULTICAST), AVAHI_ERR_INVALID_FLAGS); + AVAHI_CHECK_VALIDITY_RETURN_NULL(s, type == AVAHI_DNS_SERVER_UPDATE || type == AVAHI_DNS_SERVER_RESOLVE, AVAHI_ERR_INVALID_FLAGS); + AVAHI_CHECK_VALIDITY_RETURN_NULL(s, port != 0, AVAHI_ERR_INVALID_PORT); + AVAHI_CHECK_VALIDITY_RETURN_NULL(s, avahi_is_valid_fqdn(name), AVAHI_ERR_INVALID_HOST_NAME); +@@ -967,6 +973,7 @@ int avahi_server_add_dns_server_address( + AVAHI_CHECK_VALIDITY(s, AVAHI_IF_VALID(interface), AVAHI_ERR_INVALID_INTERFACE); + AVAHI_CHECK_VALIDITY(s, AVAHI_PROTO_VALID(protocol) && AVAHI_PROTO_VALID(address->proto), AVAHI_ERR_INVALID_PROTOCOL); + AVAHI_CHECK_VALIDITY(s, AVAHI_FLAGS_VALID(flags, AVAHI_PUBLISH_USE_MULTICAST|AVAHI_PUBLISH_USE_WIDE_AREA), AVAHI_ERR_INVALID_FLAGS); ++ AVAHI_CHECK_VALIDITY(s, !(flags & AVAHI_PUBLISH_USE_WIDE_AREA) || !(flags & AVAHI_PUBLISH_USE_MULTICAST), AVAHI_ERR_INVALID_FLAGS); + AVAHI_CHECK_VALIDITY(s, type == AVAHI_DNS_SERVER_UPDATE || type == AVAHI_DNS_SERVER_RESOLVE, AVAHI_ERR_INVALID_FLAGS); + AVAHI_CHECK_VALIDITY(s, port != 0, AVAHI_ERR_INVALID_PORT); + AVAHI_CHECK_VALIDITY(s, !domain || avahi_is_valid_domain_name(domain), AVAHI_ERR_INVALID_DOMAIN_NAME); +-- +2.45.4 + + +From 2f688b537b2af03a2005a7b8d7869b7fe84a9c17 Mon Sep 17 00:00:00 2001 +From: Evgeny Vereshchagin +Date: Wed, 1 Apr 2026 05:30:58 +0000 +Subject: [PATCH 2/3] tests: make sure AVAHI_PUBLISH_USE_WIDE_AREA is refused + +--- + avahi-client/client-test.c | 25 +++++++++++++++++++++++++ + avahi-core/avahi-test.c | 12 +++++++++++- + 2 files changed, 36 insertions(+), 1 deletion(-) + +diff --git a/avahi-client/client-test.c b/avahi-client/client-test.c +index 57750a4..42f5b70 100644 +--- a/avahi-client/client-test.c ++++ b/avahi-client/client-test.c +@@ -209,6 +209,28 @@ static void terminate(AVAHI_GCC_UNUSED AvahiTimeout *timeout, AVAHI_GCC_UNUSED v + avahi_simple_poll_quit(simple_poll); + } + ++static void test_refuse_publish_flags(AvahiEntryGroup *g, AvahiPublishFlags flags, int expected) { ++ AvahiAddress a; ++ AvahiStringList *l = NULL; ++ int r; ++ ++ r = avahi_entry_group_add_record(g, AVAHI_IF_UNSPEC, AVAHI_PROTO_UNSPEC, flags, "test.local", AVAHI_DNS_CLASS_IN, AVAHI_DNS_TYPE_CNAME, 120, "\0", 1); ++ assert(r == expected); ++ ++ avahi_address_parse("224.0.0.251", AVAHI_PROTO_UNSPEC, &a); ++ r = avahi_entry_group_add_address(g, AVAHI_IF_UNSPEC, AVAHI_PROTO_UNSPEC, flags, "test.local", &a); ++ assert(r == expected); ++ ++ r = avahi_entry_group_add_service_strlst(g, AVAHI_IF_UNSPEC, AVAHI_PROTO_UNSPEC, flags, "test", "_http._tcp", NULL, NULL, 80, l); ++ assert(r == expected); ++ ++ r = avahi_entry_group_update_service_txt_strlst(g, AVAHI_IF_UNSPEC, AVAHI_PROTO_UNSPEC, flags, "test", "_http._tcp", NULL, l); ++ assert(r == expected); ++ ++ r = avahi_entry_group_add_service_subtype(g, AVAHI_IF_UNSPEC, AVAHI_PROTO_UNSPEC, flags, "test", "_http._tcp", NULL, "_magic._sub._http._tcp"); ++ assert(r == expected); ++} ++ + int main (AVAHI_GCC_UNUSED int argc, AVAHI_GCC_UNUSED char *argv[]) { + AvahiClient *avahi; + AvahiEntryGroup *group, *group2; +@@ -261,6 +283,9 @@ int main (AVAHI_GCC_UNUSED int argc, AVAHI_GCC_UNUSED char *argv[]) { + error = avahi_entry_group_add_record (group, AVAHI_IF_UNSPEC, AVAHI_PROTO_UNSPEC, 0, "TestX", 0x01, 0x10, 120, "", 0); + assert(error != AVAHI_OK); + ++ test_refuse_publish_flags(group, AVAHI_PUBLISH_USE_WIDE_AREA, AVAHI_ERR_NOT_SUPPORTED); ++ test_refuse_publish_flags(group, AVAHI_PUBLISH_USE_WIDE_AREA|AVAHI_PUBLISH_USE_MULTICAST, AVAHI_ERR_INVALID_FLAGS); ++ + avahi_entry_group_commit (group); + + domain = avahi_domain_browser_new (avahi, AVAHI_IF_UNSPEC, AVAHI_PROTO_UNSPEC, NULL, AVAHI_DOMAIN_BROWSER_BROWSE, 0, avahi_domain_browser_callback, (char*) "omghai3u"); +diff --git a/avahi-core/avahi-test.c b/avahi-core/avahi-test.c +index 2a7872b..2bae82b 100644 +--- a/avahi-core/avahi-test.c ++++ b/avahi-core/avahi-test.c +@@ -30,6 +30,7 @@ + #include + #include + ++#include + #include + #include + #include +@@ -150,6 +151,7 @@ static void remove_entries(void) { + static void create_entries(int new_name) { + AvahiAddress a; + AvahiRecord *r; ++ int error; + + remove_entries(); + +@@ -181,7 +183,15 @@ static void create_entries(int new_name) { + goto fail; + } + +- if (avahi_server_add_dns_server_address(server, group, AVAHI_IF_UNSPEC, AVAHI_PROTO_UNSPEC, 0, NULL, AVAHI_DNS_SERVER_RESOLVE, avahi_address_parse("192.168.50.1", AVAHI_PROTO_UNSPEC, &a), 53) < 0) { ++ avahi_address_parse("192.168.50.1", AVAHI_PROTO_UNSPEC, &a); ++ ++ error = avahi_server_add_dns_server_address(server, group, AVAHI_IF_UNSPEC, AVAHI_PROTO_UNSPEC, AVAHI_PUBLISH_USE_WIDE_AREA, NULL, AVAHI_DNS_SERVER_RESOLVE, &a, 53); ++ assert(error == AVAHI_ERR_NOT_SUPPORTED); ++ ++ error = avahi_server_add_dns_server_address(server, group, AVAHI_IF_UNSPEC, AVAHI_PROTO_UNSPEC, AVAHI_PUBLISH_USE_WIDE_AREA|AVAHI_PUBLISH_USE_MULTICAST, NULL, AVAHI_DNS_SERVER_RESOLVE, &a, 53); ++ assert(error == AVAHI_ERR_INVALID_FLAGS); ++ ++ if (avahi_server_add_dns_server_address(server, group, AVAHI_IF_UNSPEC, AVAHI_PROTO_UNSPEC, 0, NULL, AVAHI_DNS_SERVER_RESOLVE, &a, 53) < 0) { + avahi_log_error("Failed to add new DNS Server address"); + goto fail; + } +-- +2.45.4 + + +From 57746739749f4b7706a0c833f7b62f2da51e6de3 Mon Sep 17 00:00:00 2001 +From: Evgeny Vereshchagin +Date: Wed, 1 Apr 2026 12:18:33 +0000 +Subject: [PATCH 3/3] build: bump + +-- +2.45.4 + diff --git a/SPECS/avahi/avahi.spec b/SPECS/avahi/avahi.spec index b2ffc517b8d..02efafbc68b 100644 --- a/SPECS/avahi/avahi.spec +++ b/SPECS/avahi/avahi.spec @@ -3,7 +3,7 @@ Summary: Local network service discovery Name: avahi Version: 0.8 -Release: 7%{?dist} +Release: 8%{?dist} License: LGPLv2+ Vendor: Microsoft Corporation Distribution: Azure Linux @@ -23,6 +23,7 @@ Patch10: CVE-2025-68276.patch Patch11: CVE-2025-68468.patch Patch12: CVE-2025-68471.patch Patch13: CVE-2026-24401.patch +Patch14: CVE-2026-34933.patch BuildRequires: automake BuildRequires: dbus-devel >= 0.90 BuildRequires: dbus-glib-devel >= 0.70 @@ -430,6 +431,9 @@ exit 0 %endif %changelog +* Thu Apr 09 2026 Azure Linux Security Servicing Account - 0.8-8 +- Patch for CVE-2026-34933 + * Tue Jan 27 2026 Azure Linux Security Servicing Account - 0.8-7 - Patch for CVE-2026-24401