cifs: make cifs_copy_sid handle a source sid with variable size subauth arrays

...and lift the restriction in id_to_sid upcall that the size must be
at least as big as a full cifs_sid.

Reviewed-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/fs/cifs/cifsacl.h b/fs/cifs/cifsacl.h
index 18c7521273a7..7e52f19f996f 100644
--- a/fs/cifs/cifsacl.h
+++ b/fs/cifs/cifsacl.h
@@ -64,6 +64,9 @@ struct cifs_sid {
         __le32 sub_auth[NUM_SUBAUTHS]; /* sub_auth[num_subauth] */
 } __attribute__((packed));
 
+/* size of a struct cifs_sid, sans sub_auth array */
+#define CIFS_SID_BASE_SIZE (1 + 1 + NUM_AUTHS)
+
 struct cifs_acl {
         __le16 revision; /* revision level */
         __le16 size;