From: Karel Zak <kzak@redhat.com>
Date: Wed, 2 Jul 2025 09:48:22 +0000 (+0200)
Subject: lsblk: fix possible use-after-free
X-Git-Tag: v2.41.2-rc1~31
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=0000a5d6fb6826fb44da5fdffb9c8b918dd54078;p=thirdparty%2Futil-linux.git

lsblk: fix possible use-after-free

Signed-off-by: Karel Zak <kzak@redhat.com>
(cherry picked from commit 02955d9434396df4019132351d8264b74811dc3f)
---

diff --git a/misc-utils/lsblk.c b/misc-utils/lsblk.c
index 3c14ca26a..6940de088 100644
--- a/misc-utils/lsblk.c
+++ b/misc-utils/lsblk.c
@@ -483,9 +483,12 @@ static char *get_type(struct lsblk_device *dev)
 		char *md_level = NULL;
 
 		ul_path_read_string(dev->sysfs, &md_level, "md/level");
-		res = (md_level && *md_level) ? md_level : xstrdup("md");
-		free(md_level);
-
+		if (md_level && *md_level)
+			res = md_level;
+		else {
+			free(md_level);		/* may be unused empty string */
+			res = xstrdup("md");
+		}
 	} else {
 		const char *type = NULL;
 		int x = 0;