From: "Christian Göttsche" <cgoettsche@seltendoof.de>
To: selinux@vger.kernel.org
Cc: "Christian Göttsche" <cgzones@googlemail.com>
Subject: [PATCH] selinux: avoid dereference of garbage after mount failure
Date: Thu, 28 Mar 2024 20:16:58 +0100 [thread overview]
Message-ID: <20240328191658.210221-1-cgoettsche@seltendoof.de> (raw)
From: Christian Göttsche <cgzones@googlemail.com>
In case kern_mount() fails and returns an error pointer return in the
error branch instead of continuing and dereferencing the error pointer.
While on it drop the never read static variable selinuxfs_mount.
Fixes: 0619f0f5e36f ("selinux: wrap selinuxfs state")
Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
---
security/selinux/selinuxfs.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)
diff --git a/security/selinux/selinuxfs.c b/security/selinux/selinuxfs.c
index d18581d741e8..7e9aa5d151b4 100644
--- a/security/selinux/selinuxfs.c
+++ b/security/selinux/selinuxfs.c
@@ -2125,7 +2125,6 @@ static struct file_system_type sel_fs_type = {
.kill_sb = sel_kill_sb,
};
-static struct vfsmount *selinuxfs_mount __ro_after_init;
struct path selinux_null __ro_after_init;
static int __init init_sel_fs(void)
@@ -2147,18 +2146,21 @@ static int __init init_sel_fs(void)
return err;
}
- selinux_null.mnt = selinuxfs_mount = kern_mount(&sel_fs_type);
- if (IS_ERR(selinuxfs_mount)) {
+ selinux_null.mnt = kern_mount(&sel_fs_type);
+ if (IS_ERR(selinux_null.mnt)) {
pr_err("selinuxfs: could not mount!\n");
- err = PTR_ERR(selinuxfs_mount);
- selinuxfs_mount = NULL;
+ err = PTR_ERR(selinux_null.mnt);
+ selinux_null.mnt = NULL;
+ return err;
}
+
selinux_null.dentry = d_hash_and_lookup(selinux_null.mnt->mnt_root,
&null_name);
if (IS_ERR(selinux_null.dentry)) {
pr_err("selinuxfs: could not lookup null!\n");
err = PTR_ERR(selinux_null.dentry);
selinux_null.dentry = NULL;
+ return err;
}
return err;
--
2.43.0
next reply other threads:[~2024-03-28 19:17 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-28 19:16 Christian Göttsche [this message]
2024-03-29 15:19 ` [PATCH] selinux: avoid dereference of garbage after mount failure Casey Schaufler
2024-04-02 2:05 ` Paul Moore
2024-04-02 10:04 ` Christian Göttsche
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