avahi: fix CVE-2023-38470

A vulnerability was found in Avahi. A reachable assertion exists
in the avahi_escape_label() function.

(From OE-Core rev: 93b4489c84f5f21e3fbcd66a39d50b5d64001a58)

Signed-off-by: Meenali Gupta <meenali.gupta@windriver.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

2 files changed, 60 insertions, 0 deletions

diff --git a/meta/recipes-connectivity/avahi/avahi_0.8.bb b/meta/recipes-connectivity/avahi/avahi_0.8.bb
index 90b33ba81b..a0b31a4697 100644
--- a/meta/recipes-connectivity/avahi/avahi_0.8.bb
+++ b/meta/recipes-connectivity/avahi/avahi_0.8.bb
@@ -27,6 +27,7 @@ SRC_URI = "${GITHUB_BASE_URI}/download/v${PV}/avahi-${PV}.tar.gz \
            file://local-ping.patch \
            file://invalid-service.patch \
            file://CVE-2023-38469.patch \
+           file://CVE-2023-38470.patch \
            "
 
 GITHUB_BASE_URI = "https://github.com/lathiat/avahi/releases/"
diff --git a/meta/recipes-connectivity/avahi/files/CVE-2023-38470.patch b/meta/recipes-connectivity/avahi/files/CVE-2023-38470.patch
new file mode 100644
index 0000000000..91f9e677ac
--- /dev/null
+++ b/meta/recipes-connectivity/avahi/files/CVE-2023-38470.patch
@@ -0,0 +1,59 @@
+From af7bfad67ca53a7c4042a4a2d85456b847e9f249 Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Petr=20Men=C5=A1=C3=ADk?= <pemensik@redhat.com>
+Date: Tue, 11 Apr 2023 15:29:59 +0200
+Subject: [PATCH] avahi: Ensure each label is at least one byte long
+
+The only allowed exception is single dot, where it should return empty
+string.
+
+Fixes #454.
+
+Upstream-Status: Backport [https://github.com/lathiat/avahi/commit/94cb6489114636940ac683515417990b55b5d66c]
+CVE: CVE-2023-38470
+
+Signed-off-by: Meenali Gupta <meenali.gupta@windriver.com>
+---
+ avahi-common/domain-test.c | 14 ++++++++++++++
+ avahi-common/domain.c      |  2 +-
+ 2 files changed, 15 insertions(+), 1 deletion(-)
+
+diff --git a/avahi-common/domain-test.c b/avahi-common/domain-test.c
+index cf763ec..3acc1c1 100644
+--- a/avahi-common/domain-test.c
++++ b/avahi-common/domain-test.c
+@@ -45,6 +45,20 @@ int main(AVAHI_GCC_UNUSED int argc, AVAHI_GCC_UNUSED char *argv[]) {
+     printf("%s\n", s = avahi_normalize_name_strdup("fo\\\\o\\..f oo."));
+     avahi_free(s);
+
++    printf("%s\n", s = avahi_normalize_name_strdup("."));
++    avahi_free(s);
++
++    s = avahi_normalize_name_strdup(",.=.}.=.?-.}.=.?.?.}.}.?.?.?.z.?.?.}.}."
++                   "}.?.?.?.r.=.=.}.=.?.}}.}.?.?.?.zM.=.=.?.?.}.}.?.?.}.}.}"
++                   ".?.?.?.r.=.=.}.=.?.}}.}.?.?.?.zM.=.=.?.?.}.}.?.?.?.zM.?`"
++                   "?.}.}.}.?.?.?.r.=.?.}.=.?.?.}.?.?.?.}.=.?.?.}??.}.}.?.?."
++                   "?.z.?.?.}.}.}.?.?.?.r.=.=.}.=.?.}}.}.?.?.?.zM.?`?.}.}.}."
++                   "??.?.zM.?`?.}.}.}.?.?.?.r.=.?.}.=.?.?.}.?.?.?.}.=.?.?.}?"
++                   "?.}.}.?.?.?.z.?.?.}.}.}.?.?.?.r.=.=.}.=.?.}}.}.?.?.?.zM."
++                   "?`?.}.}.}.?.?.?.r.=.=.?.?`.?.?}.}.}.?.?.?.r.=.?.}.=.?.?."
++                   "}.?.?.?.}.=.?.?.}");
++    assert(s == NULL);
++
+     printf("%i\n", avahi_domain_equal("\\065aa bbb\\.\\046cc.cc\\\\.dee.fff.", "Aaa BBB\\.\\.cc.cc\\\\.dee.fff"));
+     printf("%i\n", avahi_domain_equal("A", "a"));
+
+diff --git a/avahi-common/domain.c b/avahi-common/domain.c
+index 3b1ab68..e66d241 100644
+--- a/avahi-common/domain.c
++++ b/avahi-common/domain.c
+@@ -201,7 +201,7 @@ char *avahi_normalize_name(const char *s, char *ret_s, size_t size) {
+         }
+
+         if (!empty) {
+-            if (size < 1)
++            if (size < 2)
+                 return NULL;
+
+             *(r++) = '.';
+--
+2.40.0