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authorVivek Goyal <vgoyal@redhat.com>2016-07-13 10:44:50 -0400
committerPaul Moore <paul@paul-moore.com>2016-08-08 20:43:59 -0400
commit19472b69d639d58415866bf127d5f9005038c105 (patch)
treede7f757f15275283bc3153bb368cb305d8081993
parent121ab822ef21914adac2fa3730efeeb8fd762473 (diff)
downloadlinux-19472b69d639d58415866bf127d5f9005038c105.tar.bz2
selinux: Implementation for inode_copy_up_xattr() hook
When a file is copied up in overlay, we have already created file on upper/ with right label and there is no need to copy up selinux label/xattr from lower file to upper file. In fact in case of context mount, we don't want to copy up label as newly created file got its label from context= 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>
-rw-r--r--security/selinux/hooks.c16
1 files changed, 16 insertions, 0 deletions
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 40597ed00ba9..a2d510895ff3 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -3313,6 +3313,21 @@ static int selinux_inode_copy_up(struct dentry *src, struct cred **new)
return 0;
}
+static int selinux_inode_copy_up_xattr(const char *name)
+{
+ /* The copy_up hook above sets the initial context on an inode, but we
+ * don't then want to overwrite it by blindly copying all the lower
+ * xattrs up. Instead, we have to filter out SELinux-related xattrs.
+ */
+ if (strcmp(name, XATTR_NAME_SELINUX) == 0)
+ return 1; /* Discard */
+ /*
+ * Any other attribute apart from SELINUX is not claimed, supported
+ * by selinux.
+ */
+ return -EOPNOTSUPP;
+}
+
/* file security operations */
static int selinux_revalidate_file_permission(struct file *file, int mask)
@@ -6109,6 +6124,7 @@ static struct security_hook_list selinux_hooks[] = {
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(inode_copy_up_xattr, selinux_inode_copy_up_xattr),
LSM_HOOK_INIT(file_permission, selinux_file_permission),
LSM_HOOK_INIT(file_alloc_security, selinux_file_alloc_security),