diff -Nru alsa-lib-1.2.2/debian/changelog alsa-lib-1.2.2/debian/changelog
--- alsa-lib-1.2.2/debian/changelog	2021-04-07 03:33:31.000000000 +0800
+++ alsa-lib-1.2.2/debian/changelog	2021-11-01 15:25:07.000000000 +0800
@@ -1,3 +1,12 @@
+alsa-lib (1.2.2-2.1ubuntu2.5) focal; urgency=medium
+
+  * d/p/0001-ucm-fix-regexec-REG_NOMATCH-state-handling-for-defin.patch
+    - ucm: Fix a Regex parser bug, when there is no match, need to
+    set err to 0, otherwise, the caller will get a wrong match instead of
+    no match. (LP: #1949329)
+
+ -- Hui Wang <hui.wang@canonical.com>  Mon, 01 Nov 2021 15:25:07 +0800
+
 alsa-lib (1.2.2-2.1ubuntu2.4) focal; urgency=medium
 
   * d/p/0001-conf-USB-add-Cmedia-Audio-to-USB-Audio.pcm.iec958_de.patch:
diff -Nru alsa-lib-1.2.2/debian/patches/0001-ucm-fix-regexec-REG_NOMATCH-state-handling-for-defin.patch alsa-lib-1.2.2/debian/patches/0001-ucm-fix-regexec-REG_NOMATCH-state-handling-for-defin.patch
--- alsa-lib-1.2.2/debian/patches/0001-ucm-fix-regexec-REG_NOMATCH-state-handling-for-defin.patch	1970-01-01 08:00:00.000000000 +0800
+++ alsa-lib-1.2.2/debian/patches/0001-ucm-fix-regexec-REG_NOMATCH-state-handling-for-defin.patch	2021-11-01 15:24:34.000000000 +0800
@@ -0,0 +1,27 @@
+From 414e4a759b2946d2f60746ed104d425be4ddb9fc Mon Sep 17 00:00:00 2001
+From: Jaroslav Kysela <perex@perex.cz>
+Date: Wed, 12 May 2021 09:53:18 +0200
+Subject: [PATCH] ucm: fix regexec() REG_NOMATCH state handling for define
+ regex
+
+Signed-off-by: Jaroslav Kysela <perex@perex.cz>
+---
+ src/ucm/ucm_regex.c | 2 ++
+ 1 file changed, 2 insertions(+)
+
+diff --git a/src/ucm/ucm_regex.c b/src/ucm/ucm_regex.c
+index be8f277a..1471f076 100644
+--- a/src/ucm/ucm_regex.c
++++ b/src/ucm/ucm_regex.c
+@@ -166,6 +166,8 @@ int uc_mgr_define_regex(snd_use_case_mgr_t *uc_mgr, const char *name,
+ 	err = regexec(&re, s, ARRAY_SIZE(match), match, 0);
+ 	if (err < 0)
+ 		err = -errno;
++	else if (err == REG_NOMATCH)
++		err = 0;
+ 	else
+ 		err = set_variables(uc_mgr, s, ARRAY_SIZE(match), match, name);
+ 	free(s);
+-- 
+2.25.1
+
diff -Nru alsa-lib-1.2.2/debian/patches/series alsa-lib-1.2.2/debian/patches/series
--- alsa-lib-1.2.2/debian/patches/series	2021-04-07 03:33:22.000000000 +0800
+++ alsa-lib-1.2.2/debian/patches/series	2021-11-01 15:25:02.000000000 +0800
@@ -56,3 +56,4 @@
 0001-ucm-handle-correctly-Linked-configuration.patch
 0001-control-ctlparse-fix-enum-values-in-or.patch
 0001-conf-USB-add-Cmedia-Audio-to-USB-Audio.pcm.iec95.patch
+0001-ucm-fix-regexec-REG_NOMATCH-state-handling-for-defin.patch