From 37801a36b4d68892ce807264f784d818f8d0d39b Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Christian=20G=C3=B6ttsche?= Date: Thu, 28 Mar 2024 20:16:58 +0100 Subject: [PATCH] selinux: avoid dereference of garbage after mount failure MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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. Cc: stable@vger.kernel.org Fixes: 0619f0f5e36f ("selinux: wrap selinuxfs state") Signed-off-by: Christian Göttsche Signed-off-by: Paul Moore --- 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 0619a1cbbfbe..074d6c2714eb 100644 --- a/security/selinux/selinuxfs.c +++ b/security/selinux/selinuxfs.c @@ -2123,7 +2123,6 @@ 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) @@ -2145,18 +2144,21 @@ 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;