From c8e222616c7e98305bdc861db3ccac520bc29921 Mon Sep 17 00:00:00 2001 From: Jonathan Lebon Date: Thu, 28 May 2020 10:39:40 -0400 Subject: selinux: allow reading labels before policy is loaded This patch does for `getxattr` what commit 3e3e24b42043 ("selinux: allow labeling before policy is loaded") did for `setxattr`; it allows querying the current SELinux label on disk before the policy is loaded. One of the motivations described in that commit message also drives this patch: for Fedora CoreOS (and eventually RHEL CoreOS), we want to be able to move the root filesystem for example, from xfs to ext4 on RAID, on first boot, at initrd time.[1] Because such an operation works at the filesystem level, we need to be able to read the SELinux labels first from the original root, and apply them to the files of the new root. The previous commit enabled the second part of this process; this commit enables the first part. [1] https://github.com/coreos/fedora-coreos-tracker/issues/94 Acked-by: Stephen Smalley Signed-off-by: Jonathan Lebon Signed-off-by: Paul Moore --- security/selinux/hooks.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index efa6108b1ce9..ca901025802a 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -3332,7 +3332,12 @@ static int selinux_inode_getsecurity(struct inode *inode, const char *name, void char *context = NULL; struct inode_security_struct *isec; - if (strcmp(name, XATTR_SELINUX_SUFFIX)) + /* + * If we're not initialized yet, then we can't validate contexts, so + * just let vfs_getxattr fall back to using the on-disk xattr. + */ + if (!selinux_initialized(&selinux_state) || + strcmp(name, XATTR_SELINUX_SUFFIX)) return -EOPNOTSUPP; /* -- cgit 1.2.3-1.el7