From: Karel Zak <kzak@redhat.com>
Date: Thu, 24 Apr 2025 16:32:35 +0000 (+0200)
Subject: libmount: avoid calling memset() unnecessarily
X-Git-Tag: v2.41.1~37
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=15f72204593e529bff11115e4703c48c4b2c3ea3;p=thirdparty%2Futil-linux.git

libmount: avoid calling memset() unnecessarily

This is primarily to satisfy static analyzers, as memset() is defined
as a non-null function (although it does nothing when bufsiz=0).

Signed-off-by: Karel Zak <kzak@redhat.com>
(cherry picked from commit 9e96e6ed9cce4cbaf3b9ca6e61d0b0ee070685e9)
---

diff --git a/libmount/src/fs_statmount.c b/libmount/src/fs_statmount.c
index a998ee23c..31982f4a2 100644
--- a/libmount/src/fs_statmount.c
+++ b/libmount/src/fs_statmount.c
@@ -360,7 +360,11 @@ int mnt_fs_fetch_statmount(struct libmnt_fs *fs, uint64_t mask)
 
 	if (fs->stmnt) {
 		DBG(FS, ul_debugobj(fs, " reuse libmnt_stmnt"));
-		memset(fs->stmnt->buf, 0, fs->stmnt->bufsiz);
+
+		/* note that sys_statmount (re)allocates the buffer */
+		if (fs->stmnt->buf && fs->stmnt->bufsiz > 0)
+			memset(fs->stmnt->buf, 0, fs->stmnt->bufsiz);
+
 		rc = sys_statmount(fs->uniq_id, 0, mask,
 				   &fs->stmnt->buf, &fs->stmnt->bufsiz, 0);
 		buf = fs->stmnt->buf;