From: Christian Göttsche Date: Thu, 28 Mar 2024 19:16:58 +0000 (+0100) Subject: selinux: avoid dereference of garbage after mount failure X-Git-Tag: v6.6.26~184 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=477ed6789eb9f3f4d3568bb977f90c863c12724e;p=thirdparty%2Fkernel%2Fstable.git selinux: avoid dereference of garbage after mount failure commit 37801a36b4d68892ce807264f784d818f8d0d39b upstream. 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 Signed-off-by: Greg Kroah-Hartman --- diff --git a/security/selinux/selinuxfs.c b/security/selinux/selinuxfs.c index 6fa640263216f..2c23a5a286086 100644 --- a/security/selinux/selinuxfs.c +++ b/security/selinux/selinuxfs.c @@ -2135,7 +2135,6 @@ 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) @@ -2157,18 +2156,21 @@ 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;