fix cve-2021-3468

avahi.spec

@@ -3,7 +3,7 @@
 
 Name:             avahi
 Version:          0.8
-Release:          5
+Release:          6
 Summary:          Avahi is a local network service discovery
 License:          LGPLv2+
 URL:              http://avahi.org
@@ -17,6 +17,8 @@ Patch3:           0003-fix-requires-in-pc-file.patch
 Patch4:           0004-fix-bytestring-decoding-for-proper-display.patch
 Patch5:           0005-avahi_dns_packet_consume_uint32-fix-potential-undefi.patch
 
+Patch6001:        backport-CVE-2021-3468.patch
+
 BuildRequires:    gcc automake libtool desktop-file-utils gtk2-devel glib2-devel
 BuildRequires:    libcap-devel expat-devel gdbm-devel
 BuildRequires:    intltool perl-XML-Parser xmltoman systemd libevent-devel
@@ -518,6 +520,12 @@ fi
 %{_mandir}/man8/*
 
 %changelog
+* Tue Jun 15 2021 wangkerong <wangkerong@huawei.com> - 0.8-6
+- Type:CVE
+- ID:CVE-2021-3468
+- SUG:NA
+- DESC:fix CVE-2021-3468
+
 * Thu May 20 2021 hanhui <hanhui15@huawei.com> - 0.8-5
 - Type:enhancement
 - ID:NA

backport-CVE-2021-3468.patch

@@ -0,0 +1,37 @@
+From 447affe29991ee99c6b9732fc5f2c1048a611d3b Mon Sep 17 00:00:00 2001
+From: Riccardo Schirone <sirmy15@gmail.com>
+Date: Fri, 26 Mar 2021 11:50:24 +0100
+Subject: [PATCH] Avoid infinite-loop in avahi-daemon by handling HUP event in
+ client_work
+
+If a client fills the input buffer, client_work() disables the
+AVAHI_WATCH_IN event, thus preventing the function from executing the
+`read` syscall the next times it is called. However, if the client then
+terminates the connection, the socket file descriptor receives a HUP
+event, which is not handled, thus the kernel keeps marking the HUP event
+as occurring. While iterating over the file descriptors that triggered
+an event, the client file descriptor will keep having the HUP event and
+the client_work() function is always called with AVAHI_WATCH_HUP but
+without nothing being done, thus entering an infinite loop.
+
+See https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=984938
+---
+ avahi-daemon/simple-protocol.c | 5 +++++
+ 1 file changed, 5 insertions(+)
+
+diff --git a/avahi-daemon/simple-protocol.c b/avahi-daemon/simple-protocol.c
+index 3e0ebb11..6c0274d6 100644
+--- a/avahi-daemon/simple-protocol.c
++++ b/avahi-daemon/simple-protocol.c
+@@ -424,6 +424,11 @@ static void client_work(AvahiWatch *watch, AVAHI_GCC_UNUSED int fd, AvahiWatchEv
+         }
+     }
+ 
++    if (events & AVAHI_WATCH_HUP) {
++        client_free(c);
++        return;
++    }
++
+     c->server->poll_api->watch_update(
+         watch,
+         (c->outbuf_length > 0 ? AVAHI_WATCH_OUT : 0) |