selinux: Implementation for inode_copy_up() hook
A file is being copied up for overlay file system. Prepare a new set of
creds and set create_sid appropriately so that new file is created with
appropriate label.
Overlay inode has right label for both context and non-context mount
cases. In case of non-context mount, overlay inode will have the label
of lower file and in case of context mount, overlay inode will have
the label from context= mount option.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <paul@paul-moore.com>
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 880f953..40597ed 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -3293,6 +3293,26 @@
*secid = isec->sid;
}
+static int selinux_inode_copy_up(struct dentry *src, struct cred **new)
+{
+ u32 sid;
+ struct task_security_struct *tsec;
+ struct cred *new_creds = *new;
+
+ if (new_creds == NULL) {
+ new_creds = prepare_creds();
+ if (!new_creds)
+ return -ENOMEM;
+ }
+
+ tsec = new_creds->security;
+ /* Get label from overlay inode and set it in create_sid */
+ selinux_inode_getsecid(d_inode(src), &sid);
+ tsec->create_sid = sid;
+ *new = new_creds;
+ return 0;
+}
+
/* file security operations */
static int selinux_revalidate_file_permission(struct file *file, int mask)
@@ -6088,6 +6108,7 @@
LSM_HOOK_INIT(inode_setsecurity, selinux_inode_setsecurity),
LSM_HOOK_INIT(inode_listsecurity, selinux_inode_listsecurity),
LSM_HOOK_INIT(inode_getsecid, selinux_inode_getsecid),
+ LSM_HOOK_INIT(inode_copy_up, selinux_inode_copy_up),
LSM_HOOK_INIT(file_permission, selinux_file_permission),
LSM_HOOK_INIT(file_alloc_security, selinux_file_alloc_security),
