[hardknott][PATCH 12/13] avahi: apply fix for CVE-2021-3468
From: Anuj Mittal <hidden>
Date: 2021-06-22 09:51:11
Subsystem:
the rest · Maintainer:
Linus Torvalds
From: Ross Burton <redacted> This patch isn't yet upstream but it has been submitted and other distros are shipping it. Signed-off-by: Ross Burton <redacted> Signed-off-by: Richard Purdie <redacted> (cherry picked from commit ea33a4a2df4600a55b268e9d57e7396c30f3d123) Signed-off-by: Anuj Mittal <redacted> --- meta/recipes-connectivity/avahi/avahi_0.8.bb | 1 + .../avahi/files/handle-hup.patch | 41 +++++++++++++++++++ 2 files changed, 42 insertions(+) create mode 100644 meta/recipes-connectivity/avahi/files/handle-hup.patch
diff --git a/meta/recipes-connectivity/avahi/avahi_0.8.bb b/meta/recipes-connectivity/avahi/avahi_0.8.bb
index 23c0e8d823..a07cdbd03c 100644
--- a/meta/recipes-connectivity/avahi/avahi_0.8.bb
+++ b/meta/recipes-connectivity/avahi/avahi_0.8.bb@@ -24,6 +24,7 @@ SRC_URI = "https://github.com/lathiat/avahi/releases/download/v${PV}/avahi-${PV} file://99avahi-autoipd \ file://initscript.patch \ file://0001-Fix-opening-etc-resolv.conf-error.patch \ + file://handle-hup.patch \ " UPSTREAM_CHECK_URI = "https://github.com/lathiat/avahi/releases/"
diff --git a/meta/recipes-connectivity/avahi/files/handle-hup.patch b/meta/recipes-connectivity/avahi/files/handle-hup.patch
new file mode 100644
index 0000000000..26632e5443
--- /dev/null
+++ b/meta/recipes-connectivity/avahi/files/handle-hup.patch@@ -0,0 +1,41 @@ +CVE: CVE-2021-3468 +Upstream-Status: Submitted [https://github.com/lathiat/avahi/pull/330] +Signed-off-by: Ross Burton <ross.burton@arm.com> + +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) |
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2.31.1