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, 137 insertions, 0 deletions

diff --git a/security/selinux/include/netlabel.h b/security/selinux/include/netlabel.h
new file mode 100644
index 000000000..5731c0dcd
--- /dev/null
+++ b/security/selinux/include/netlabel.h
@@ -0,0 +1,137 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * SELinux interface to the NetLabel subsystem
+ *
+ * Author: Paul Moore <paul@paul-moore.com>
+ */
+
+/*
+ * (c) Copyright Hewlett-Packard Development Company, L.P., 2006
+ */
+
+#ifndef _SELINUX_NETLABEL_H_
+#define _SELINUX_NETLABEL_H_
+
+#include <linux/types.h>
+#include <linux/fs.h>
+#include <linux/net.h>
+#include <linux/skbuff.h>
+#include <net/sock.h>
+#include <net/request_sock.h>
+#include <net/sctp/structs.h>
+
+#include "avc.h"
+#include "objsec.h"
+
+#ifdef CONFIG_NETLABEL
+void selinux_netlbl_cache_invalidate(void);
+
+void selinux_netlbl_err(struct sk_buff *skb, u16 family, int error,
+			int gateway);
+
+void selinux_netlbl_sk_security_free(struct sk_security_struct *sksec);
+void selinux_netlbl_sk_security_reset(struct sk_security_struct *sksec);
+
+int selinux_netlbl_skbuff_getsid(struct sk_buff *skb, u16 family, u32 *type,
+				 u32 *sid);
+int selinux_netlbl_skbuff_setsid(struct sk_buff *skb, u16 family, u32 sid);
+int selinux_netlbl_sctp_assoc_request(struct sctp_association *asoc,
+				      struct sk_buff *skb);
+int selinux_netlbl_inet_conn_request(struct request_sock *req, u16 family);
+void selinux_netlbl_inet_csk_clone(struct sock *sk, u16 family);
+void selinux_netlbl_sctp_sk_clone(struct sock *sk, struct sock *newsk);
+int selinux_netlbl_socket_post_create(struct sock *sk, u16 family);
+int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec,
+				struct sk_buff *skb, u16 family,
+				struct common_audit_data *ad);
+int selinux_netlbl_socket_setsockopt(struct socket *sock, int level,
+				     int optname);
+int selinux_netlbl_socket_connect(struct sock *sk, struct sockaddr *addr);
+int selinux_netlbl_socket_connect_locked(struct sock *sk,
+					 struct sockaddr *addr);
+
+#else
+static inline void selinux_netlbl_cache_invalidate(void)
+{
+	return;
+}
+
+static inline void selinux_netlbl_err(struct sk_buff *skb, u16 family,
+				      int error, int gateway)
+{
+	return;
+}
+
+static inline void
+selinux_netlbl_sk_security_free(struct sk_security_struct *sksec)
+{
+	return;
+}
+
+static inline void
+selinux_netlbl_sk_security_reset(struct sk_security_struct *sksec)
+{
+	return;
+}
+
+static inline int selinux_netlbl_skbuff_getsid(struct sk_buff *skb, u16 family,
+					       u32 *type, u32 *sid)
+{
+	*type = NETLBL_NLTYPE_NONE;
+	*sid = SECSID_NULL;
+	return 0;
+}
+static inline int selinux_netlbl_skbuff_setsid(struct sk_buff *skb, u16 family,
+					       u32 sid)
+{
+	return 0;
+}
+
+static inline int
+selinux_netlbl_sctp_assoc_request(struct sctp_association *asoc,
+				  struct sk_buff *skb)
+{
+	return 0;
+}
+static inline int selinux_netlbl_inet_conn_request(struct request_sock *req,
+						   u16 family)
+{
+	return 0;
+}
+static inline void selinux_netlbl_inet_csk_clone(struct sock *sk, u16 family)
+{
+	return;
+}
+static inline void selinux_netlbl_sctp_sk_clone(struct sock *sk,
+						struct sock *newsk)
+{
+	return;
+}
+static inline int selinux_netlbl_socket_post_create(struct sock *sk, u16 family)
+{
+	return 0;
+}
+static inline int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec,
+					      struct sk_buff *skb, u16 family,
+					      struct common_audit_data *ad)
+{
+	return 0;
+}
+static inline int selinux_netlbl_socket_setsockopt(struct socket *sock,
+						   int level, int optname)
+{
+	return 0;
+}
+static inline int selinux_netlbl_socket_connect(struct sock *sk,
+						struct sockaddr *addr)
+{
+	return 0;
+}
+static inline int selinux_netlbl_socket_connect_locked(struct sock *sk,
+						       struct sockaddr *addr)
+{
+	return 0;
+}
+#endif /* CONFIG_NETLABEL */
+
+#endif