From: Tobias Stoeckmann <tobias@stoeckmann.org>
Date: Wed, 8 Apr 2026 19:48:13 +0000 (+0200)
Subject: libblkid: Fix parse_dev debug output
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d799ef7ef34a96d8fe356362c7139b331e197dc6;p=thirdparty%2Futil-linux.git

libblkid: Fix parse_dev debug output

A parse_dev debug line erroneously uses %*s instead of %.*s. While this
does not lead to out of boundary access because the line is properly
NUL-escaped by fgets, the output is incorrect.

Simply replace the ending char with NUL for debug, since the line is
modified a few lines below anyway. This offers more safety for
refactoring in the future if fgets is ever replaced with getline,
possibly leading to lines longer than INT_MAX.

Signed-off-by: Tobias Stoeckmann <tobias@stoeckmann.org>
---

diff --git a/libblkid/src/read.c b/libblkid/src/read.c
index 898ec3e4e..b922c5642 100644
--- a/libblkid/src/read.c
+++ b/libblkid/src/read.c
@@ -187,8 +187,12 @@ static int parse_dev(blkid_cache cache, blkid_dev *dev, char **cp)
 	start = skip_over_blank(start + 1);
 	end = skip_over_word(start);
 
-	DBG(READ, ul_debug("device should be %*s",
-			       (int)(end - start), start));
+	ON_DBG(READ, {
+		char c = *end;
+		*end = '\0';
+		ul_debug("device should be %s", start);
+		*end = c;
+	});
 
 	if (**cp == '>')
 		*cp = end;