[OE-core][kirkstone 08/16] avahi: fix CVE-2023-38473

Steve Sakoman
2023-11-22T02:31:34Z

From: Meenali Gupta <meenali.gupta@windriver.com>

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

Signed-off-by: Meenali Gupta <meenali.gupta@windriver.com>
Signed-off-by: Steve Sakoman <steve@sakoman.com>
---
meta/recipes-connectivity/avahi/avahi_0.8.bb | 1 +
.../avahi/files/CVE-2023-38473.patch | 108 ++++++++++++++++++
2 files changed, 109 insertions(+)
create mode 100644 meta/recipes-connectivity/avahi/files/CVE-2023-38473.patch

diff --git a/meta/recipes-connectivity/avahi/avahi_0.8.bb b/meta/recipes-connectivity/avahi/avahi_0.8.bb
index 23801a7e54..af5284a252 100644
--- a/meta/recipes-connectivity/avahi/avahi_0.8.bb
+++ b/meta/recipes-connectivity/avahi/avahi_0.8.bb
@@ -30,6 +30,7 @@ SRC_URI = "https://github.com/lathiat/avahi/releases/download/v${PV}/avahi-${PV}
file://CVE-2023-38470.patch \
file://CVE-2023-38469.patch \
file://CVE-2023-38472.patch \
+ file://CVE-2023-38473.patch \
"

UPSTREAM_CHECK_URI = "https://github.com/lathiat/avahi/releases/"
diff --git a/meta/recipes-connectivity/avahi/files/CVE-2023-38473.patch b/meta/recipes-connectivity/avahi/files/CVE-2023-38473.patch
new file mode 100644
index 0000000000..8a372a072a
--- /dev/null
+++ b/meta/recipes-connectivity/avahi/files/CVE-2023-38473.patch
@@ -0,0 +1,108 @@
+From b448c9f771bada14ae8de175695a9729f8646797 Mon Sep 17 00:00:00 2001
+From: Michal Sekletar <msekleta@redhat.com>
+Date: Wed, 11 Oct 2023 17:45:44 +0200
+Subject: [PATCH]common: derive alternative host name from its
+ unescaped version
+
+Normalization of input makes sure we don't have to deal with special
+cases like unescaped dot at the end of label.
+
+Upstream-Status: Backport [https://github.com/lathiat/avahi/commit/b448c9f771bada14ae8de175695a9729f8646797]
+CVE: CVE-2023-38473
+
+Signed-off-by: Meenali Gupta <meenali.gupta@windriver.com>
+---
+ avahi-common/alternative-test.c | 3 +++
+ avahi-common/alternative.c | 27 +++++++++++++++++++--------
+ 2 files changed, 22 insertions(+), 8 deletions(-)
+
+diff --git a/avahi-common/alternative-test.c b/avahi-common/alternative-test.c
+index 9255435..681fc15 100644
+--- a/avahi-common/alternative-test.c
++++ b/avahi-common/alternative-test.c
+@@ -31,6 +31,9 @@ int main(AVAHI_GCC_UNUSED int argc, AVAHI_GCC_UNUSED char *argv[]) {
+ const char* const test_strings[] = {
+ "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX",
+ "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXüüüüüüü",
++ ").",
++ "\\.",
++ "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA\\\\",
+ "gurke",
+ "-",
+ " #",
+diff --git a/avahi-common/alternative.c b/avahi-common/alternative.c
+index b3d39f0..a094e6d 100644
+--- a/avahi-common/alternative.c
++++ b/avahi-common/alternative.c
+@@ -49,15 +49,20 @@ static void drop_incomplete_utf8(char *c) {
+ }
+
+ char *avahi_alternative_host_name(const char *s) {
++ char label[AVAHI_LABEL_MAX], alternative[AVAHI_LABEL_MAX*4+1];
++ char *alt, *r, *ret;
+ const char *e;
+- char *r;
++ size_t len;
+
+ assert(s);
+
+ if (!avahi_is_valid_host_name(s))
+ return NULL;
+
+- if ((e = strrchr(s, '-'))) {
++ if (!avahi_unescape_label(&s, label, sizeof(label)))
++ return NULL;
++
++ if ((e = strrchr(label, '-'))) {
+ const char *p;
+
+ e++;
+@@ -74,19 +79,18 @@ char *avahi_alternative_host_name(const char *s) {
+
+ if (e) {
+ char *c, *m;
+- size_t l;
+ int n;
+
+ n = atoi(e)+1;
+ if (!(m = avahi_strdup_printf("%i", n)))
+ return NULL;
+
+- l = e-s-1;
++ len = e-label-1;
+
+- if (l >= AVAHI_LABEL_MAX-1-strlen(m)-1)
+- l = AVAHI_LABEL_MAX-1-strlen(m)-1;
++ if (len >= AVAHI_LABEL_MAX-1-strlen(m)-1)
++ len = AVAHI_LABEL_MAX-1-strlen(m)-1;
+
+- if (!(c = avahi_strndup(s, l))) {
++ if (!(c = avahi_strndup(label, len))) {
+ avahi_free(m);
+ return NULL;
+ }
+@@ -100,7 +104,7 @@ char *avahi_alternative_host_name(const char *s) {
+ } else {
+ char *c;
+
+- if (!(c = avahi_strndup(s, AVAHI_LABEL_MAX-1-2)))
++ if (!(c = avahi_strndup(label, AVAHI_LABEL_MAX-1-2)))
+ return NULL;
+
+ drop_incomplete_utf8(c);
+@@ -109,6 +113,13 @@ char *avahi_alternative_host_name(const char *s) {
+ avahi_free(c);
+ }
+
++ alt = alternative;
++ len = sizeof(alternative);
++ ret = avahi_escape_label(r, strlen(r), &alt, &len);
++
++ avahi_free(r);
++ r = avahi_strdup(ret);
++
+ assert(avahi_is_valid_host_name(r));
+
+ return r;
+--
+2.40.0
--
2.34.1