[PATCH 5/8] SELinux: Stub in copy-up handling

From: David Howells
Date: Thu Jun 18 2015 - 09:33:22 EST


Provide stubs for union/overlay copy-up handling. The xattr copy up stub
discards lower SELinux xattrs rather than letting them be copied up so that
the security label on the copy doesn't get corrupted.

Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
---

security/selinux/hooks.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)

diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index ffa5a642629a..c5d893e2ff23 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -3200,6 +3200,20 @@ static void selinux_inode_getsecid(const struct inode *inode, u32 *secid)
*secid = isec->sid;
}

+static int selinux_inode_copy_up(struct dentry *src, struct dentry *dst)
+{
+ return 0;
+}
+
+static int selinux_inode_copy_up_xattr(struct dentry *src, struct dentry *dst,
+ const char *name, void *value,
+ size_t *size)
+{
+ if (strcmp(name, XATTR_NAME_SELINUX) == 0)
+ return 1; /* Discard */
+ return 0;
+}
+
/* file security operations */

static int selinux_revalidate_file_permission(struct file *file, int mask)
@@ -5917,6 +5931,8 @@ static struct security_operations selinux_ops = {
.inode_setsecurity = selinux_inode_setsecurity,
.inode_listsecurity = selinux_inode_listsecurity,
.inode_getsecid = selinux_inode_getsecid,
+ .inode_copy_up = selinux_inode_copy_up,
+ .inode_copy_up_xattr = selinux_inode_copy_up_xattr,

.file_permission = selinux_file_permission,
.file_alloc_security = selinux_file_alloc_security,

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