openrisc: fix arbitrary kernel memory access via or1k_atomic syscallgrafted

sys_or1k_atomic() (syscall 244 in the "or1k" ABI) takes two user
pointers, v1 and v2, and swaps the words they point to in hand-written
assembly.

    l.lwz   r29,0(r4)
    l.lwz   r27,0(r5)
    l.sw    0(r4),r27
    l.sw    0(r5),r29

The pointers are not checked with access_ok(). The four memory
accesses also have no exception table entries.

A caller passes a kernel address as either pointer, and the syscall
reads from and writes to it directly.

This gives an unprivileged process a kernel read/write primitive. It
overwrites kernel data such as the sys_call_table, gaining code
execution in kernel context.

Check both pointers before entering the critical section. Add fixups
for the four memory accesses so faults on valid but unmapped user
addresses return -EFAULT.

[shorne@gmail.com: fix comment style]
Fixes: 9d02a4283e9c ("OpenRISC: Boot code")
Cc: stable@vger.kernel.org
Signed-off-by: Ali Ahmet Memis <ali@iusegentoo.com>
Signed-off-by: Stafford Horne <shorne@gmail.com>

1 files changed, 70 insertions, 0 deletions

diff --git a/fs/smb/server/auth.h b/fs/smb/server/auth.h
new file mode 100644
index 000000000..f14b7c033
--- /dev/null
+++ b/fs/smb/server/auth.h
@@ -0,0 +1,70 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ *   Copyright (C) 2018 Samsung Electronics Co., Ltd.
+ */
+
+#ifndef __AUTH_H__
+#define __AUTH_H__
+
+#include "ntlmssp.h"
+
+#ifdef CONFIG_SMB_SERVER_KERBEROS5
+#define AUTH_GSS_LENGTH		96
+#define AUTH_GSS_PADDING	0
+#else
+#define AUTH_GSS_LENGTH		74
+#define AUTH_GSS_PADDING	6
+#endif
+
+#define CIFS_HMAC_MD5_HASH_SIZE	(16)
+#define CIFS_NTHASH_SIZE	(16)
+
+/*
+ * Size of the ntlm client response
+ */
+#define CIFS_AUTH_RESP_SIZE		24
+#define CIFS_SMB1_SIGNATURE_SIZE	8
+#define CIFS_SMB1_SESSKEY_SIZE		16
+
+#define KSMBD_AUTH_NTLMSSP	0x0001
+#define KSMBD_AUTH_KRB5		0x0002
+#define KSMBD_AUTH_MSKRB5	0x0004
+#define KSMBD_AUTH_KRB5U2U	0x0008
+
+struct ksmbd_session;
+struct ksmbd_conn;
+struct ksmbd_work;
+struct kvec;
+
+int ksmbd_crypt_message(struct ksmbd_work *work, struct kvec *iov,
+			unsigned int nvec, int enc);
+void ksmbd_copy_gss_neg_header(void *buf);
+int ksmbd_auth_ntlmv2(struct ksmbd_conn *conn, struct ksmbd_session *sess,
+		      struct ntlmv2_resp *ntlmv2, int blen, char *domain_name,
+		      char *cryptkey, char *sess_key);
+int ksmbd_decode_ntlmssp_auth_blob(struct authenticate_message *authblob,
+				   int blob_len, struct ksmbd_conn *conn,
+				   struct ksmbd_session *sess, char *sess_key);
+int ksmbd_decode_ntlmssp_neg_blob(struct negotiate_message *negblob,
+				  int blob_len, struct ksmbd_conn *conn);
+unsigned int
+ksmbd_build_ntlmssp_challenge_blob(struct challenge_message *chgblob,
+				   struct ksmbd_conn *conn);
+int ksmbd_krb5_authenticate(struct ksmbd_session *sess, char *in_blob,
+			    int in_len, char *out_blob, int *out_len,
+			    char *sess_key);
+void ksmbd_sign_smb2_pdu(struct ksmbd_conn *conn, char *key, struct kvec *iov,
+			 int n_vec, char *sig);
+void ksmbd_sign_smb3_pdu(struct ksmbd_conn *conn, char *key, struct kvec *iov,
+			 int n_vec, char *sig);
+int ksmbd_gen_smb30_signingkey(struct ksmbd_session *sess,
+			       struct ksmbd_conn *conn);
+int ksmbd_gen_smb311_signingkey(struct ksmbd_session *sess,
+				struct ksmbd_conn *conn);
+void ksmbd_gen_smb30_encryptionkey(struct ksmbd_conn *conn,
+				   struct ksmbd_session *sess);
+void ksmbd_gen_smb311_encryptionkey(struct ksmbd_conn *conn,
+				    struct ksmbd_session *sess);
+int ksmbd_gen_preauth_integrity_hash(struct ksmbd_conn *conn, char *buf,
+				     __u8 *pi_hash);
+#endif