From 486b4f7426e49998c79dff63c698c4ad8c988ec6 Mon Sep 17 00:00:00 2001 From: Michal Sekletar Date: Thu, 17 Aug 2023 17:30:55 +0200 Subject: [PATCH] Fix CVE-2021-3468 Resolves: #1944092 --- ...oop-in-avahi-daemon-by-handling-HUP-.patch | 40 +++++++++++++++++++ avahi.spec | 6 ++- 2 files changed, 45 insertions(+), 1 deletion(-) create mode 100644 0001-Avoid-infinite-loop-in-avahi-daemon-by-handling-HUP-.patch diff --git a/0001-Avoid-infinite-loop-in-avahi-daemon-by-handling-HUP-.patch b/0001-Avoid-infinite-loop-in-avahi-daemon-by-handling-HUP-.patch new file mode 100644 index 0000000..12b9444 --- /dev/null +++ b/0001-Avoid-infinite-loop-in-avahi-daemon-by-handling-HUP-.patch @@ -0,0 +1,40 @@ +From 447affe29991ee99c6b9732fc5f2c1048a611d3b Mon Sep 17 00:00:00 2001 +From: Riccardo Schirone +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 3e0ebb1..6c0274d 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) | +-- +2.40.0 + diff --git a/avahi.spec b/avahi.spec index e60c24b..8fc34db 100644 --- a/avahi.spec +++ b/avahi.spec @@ -48,7 +48,7 @@ Name: avahi Version: 0.8 -Release: 12%{?dist} +Release: 13%{?dist} Summary: Local network service discovery License: LGPLv2+ URL: http://avahi.org @@ -132,6 +132,7 @@ Patch8: 0008-Ship-avahi-discover-1-bssh-1-and-bvnc-1-also-for-GTK.patch Patch9: 0009-fix-requires-in-pc-file.patch Patch10: 0010-fix-bytestring-decoding-for-proper-display.patch Patch11: 0011-avahi_dns_packet_consume_uint32-fix-potential-undefi.patch +Patch12: 0001-Avoid-infinite-loop-in-avahi-daemon-by-handling-HUP-.patch ## downstream patches Patch100: avahi-0.6.30-mono-libdir.patch @@ -827,6 +828,9 @@ exit 0 %changelog +* Thu Aug 17 2023 Michal Sekletar - 0.8-13 +- Fix CVE-2021-3468 (#1944092) + * Mon Feb 21 2022 Michal Sekletár - 0.8-12 - make sure we get compiled with -fstack-protector-strong (#2044643)