1From af7bfad67ca53a7c4042a4a2d85456b847e9f249 Mon Sep 17 00:00:00 2001
2From: =?UTF-8?q?Petr=20Men=C5=A1=C3=ADk?= <pemensik@redhat.com>
3Date: Tue, 11 Apr 2023 15:29:59 +0200
4Subject: [PATCH] avahi: Ensure each label is at least one byte long
5
6The only allowed exception is single dot, where it should return empty
7string.
8
9Fixes #454.
10
11Upstream-Status: Backport [https://github.com/lathiat/avahi/commit/94cb6489114636940ac683515417990b55b5d66c]
12CVE: CVE-2023-38470
13
14Signed-off-by: Meenali Gupta <meenali.gupta@windriver.com>
15---
16 avahi-common/domain-test.c | 14 ++++++++++++++
17 avahi-common/domain.c      |  2 +-
18 2 files changed, 15 insertions(+), 1 deletion(-)
19
20diff --git a/avahi-common/domain-test.c b/avahi-common/domain-test.c
21index cf763ec..3acc1c1 100644
22--- a/avahi-common/domain-test.c
23+++ b/avahi-common/domain-test.c
24@@ -45,6 +45,20 @@ int main(AVAHI_GCC_UNUSED int argc, AVAHI_GCC_UNUSED char *argv[]) {
25     printf("%s\n", s = avahi_normalize_name_strdup("fo\\\\o\\..f oo."));
26     avahi_free(s);
27
28+    printf("%s\n", s = avahi_normalize_name_strdup("."));
29+    avahi_free(s);
30+
31+    s = avahi_normalize_name_strdup(",.=.}.=.?-.}.=.?.?.}.}.?.?.?.z.?.?.}.}."
32+		    "}.?.?.?.r.=.=.}.=.?.}}.}.?.?.?.zM.=.=.?.?.}.}.?.?.}.}.}"
33+		    ".?.?.?.r.=.=.}.=.?.}}.}.?.?.?.zM.=.=.?.?.}.}.?.?.?.zM.?`"
34+		    "?.}.}.}.?.?.?.r.=.?.}.=.?.?.}.?.?.?.}.=.?.?.}??.}.}.?.?."
35+		    "?.z.?.?.}.}.}.?.?.?.r.=.=.}.=.?.}}.}.?.?.?.zM.?`?.}.}.}."
36+		    "??.?.zM.?`?.}.}.}.?.?.?.r.=.?.}.=.?.?.}.?.?.?.}.=.?.?.}?"
37+		    "?.}.}.?.?.?.z.?.?.}.}.}.?.?.?.r.=.=.}.=.?.}}.}.?.?.?.zM."
38+		    "?`?.}.}.}.?.?.?.r.=.=.?.?`.?.?}.}.}.?.?.?.r.=.?.}.=.?.?."
39+		    "}.?.?.?.}.=.?.?.}");
40+    assert(s == NULL);
41+
42     printf("%i\n", avahi_domain_equal("\\065aa bbb\\.\\046cc.cc\\\\.dee.fff.", "Aaa BBB\\.\\.cc.cc\\\\.dee.fff"));
43     printf("%i\n", avahi_domain_equal("A", "a"));
44
45diff --git a/avahi-common/domain.c b/avahi-common/domain.c
46index 3b1ab68..e66d241 100644
47--- a/avahi-common/domain.c
48+++ b/avahi-common/domain.c
49@@ -201,7 +201,7 @@ char *avahi_normalize_name(const char *s, char *ret_s, size_t size) {
50         }
51
52         if (!empty) {
53-            if (size < 1)
54+            if (size < 2)
55                 return NULL;
56
57             *(r++) = '.';
58--
592.40.0
60