Attached patch to Fix build warning: cifs-utils/mount.cifs.c:1726:
warning: the use of `mktemp' is dangerous, better use `mkstemp' or `mkdtemp'
Use of mktemp() has been deprecated (e.g. due to security issues with
symlink races), and instead mkstemp is often recommended. Change
the use of mktemp to mkstemp in del_mtab in cifs-utils
Fixes: f46dd7661cfb ("mount.cifs: Properly update mtab during remount")
Opinions? Better way to address it?
--
Thanks,
Steve
From f85c0c63adb4422b300770bfc2d844742e0fccd7 Mon Sep 17 00:00:00 2001
From: Steve French <stfrench@xxxxxxxxxxxxx>
Date: Mon, 20 Jan 2025 18:34:38 -0600
Subject: [PATCH] cifs-utils: avoid using mktemp when updating mtab
Fix build warning: cifs-utils/mount.cifs.c:1726:
warning: the use of `mktemp' is dangerous, better use `mkstemp' or `mkdtemp'
Use of mktemp() has been deprecated (e.g. due to security issues with
symlink races), and instead mkstemp is often recommended. Change
the use of mktemp to mkstemp in del_mtab in cifs-utils
Fixes: f46dd7661cfb ("mount.cifs: Properly update mtab during remount")
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
---
mount.cifs.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/mount.cifs.c b/mount.cifs.c
index e46693e..7605130 100644
--- a/mount.cifs.c
+++ b/mount.cifs.c
@@ -41,6 +41,7 @@
#include <mntent.h>
#include <fcntl.h>
#include <limits.h>
+#include <stdbool.h>
#include <paths.h>
#include <libgen.h>
#include <time.h>
@@ -1688,7 +1689,7 @@ add_mtab_exit:
static int
del_mtab(char *mountpoint)
{
- int len, tmprc, rc = 0;
+ int len, tmprc, rc = 0, tmpfd;
FILE *mnttmp, *mntmtab;
struct mntent *mountent;
char *mtabfile, *mtabdir, *mtabtmpfile = NULL;
@@ -1723,8 +1724,9 @@ del_mtab(char *mountpoint)
goto del_mtab_exit;
}
- mtabtmpfile = mktemp(mtabtmpfile);
- if (!mtabtmpfile) {
+ // Use mkstemp instead of mktemp
+ tmpfd = mkstemp(mtabtmpfile);
+ if (tmpfd == -1) {
fprintf(stderr, "del_mtab: cannot setup tmp file destination\n");
rc = EX_FILEIO;
goto del_mtab_exit;
@@ -1734,13 +1736,15 @@ del_mtab(char *mountpoint)
if (!mntmtab) {
fprintf(stderr, "del_mtab: could not update mount table\n");
rc = EX_FILEIO;
+ close(tmpfd);
goto del_mtab_exit;
}
- mnttmp = setmntent(mtabtmpfile, "w");
+ mnttmp = fdopen(tmpfd, "w");
if (!mnttmp) {
fprintf(stderr, "del_mtab: could not update mount table\n");
endmntent(mntmtab);
+ close(tmpfd);
rc = EX_FILEIO;
goto del_mtab_exit;
}
--
2.43.0
