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, 50 insertions, 0 deletions

diff --git a/include/net/tcp_states.h b/include/net/tcp_states.h
new file mode 100644
index 000000000..d60e8148f
--- /dev/null
+++ b/include/net/tcp_states.h
@@ -0,0 +1,50 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * INET		An implementation of the TCP/IP protocol suite for the LINUX
+ *		operating system.  INET is implemented using the  BSD Socket
+ *		interface as the means of communication with the user level.
+ *
+ *		Definitions for the TCP protocol sk_state field.
+ */
+#ifndef _LINUX_TCP_STATES_H
+#define _LINUX_TCP_STATES_H
+
+enum {
+	TCP_ESTABLISHED = 1,
+	TCP_SYN_SENT,
+	TCP_SYN_RECV,
+	TCP_FIN_WAIT1,
+	TCP_FIN_WAIT2,
+	TCP_TIME_WAIT,
+	TCP_CLOSE,
+	TCP_CLOSE_WAIT,
+	TCP_LAST_ACK,
+	TCP_LISTEN,
+	TCP_CLOSING,	/* Now a valid state */
+	TCP_NEW_SYN_RECV,
+	TCP_BOUND_INACTIVE, /* Pseudo-state for inet_diag */
+
+	TCP_MAX_STATES	/* Leave at the end! */
+};
+
+#define TCP_STATE_MASK	0xF
+
+#define TCP_ACTION_FIN	(1 << TCP_CLOSE)
+
+enum {
+	TCPF_ESTABLISHED = (1 << TCP_ESTABLISHED),
+	TCPF_SYN_SENT	 = (1 << TCP_SYN_SENT),
+	TCPF_SYN_RECV	 = (1 << TCP_SYN_RECV),
+	TCPF_FIN_WAIT1	 = (1 << TCP_FIN_WAIT1),
+	TCPF_FIN_WAIT2	 = (1 << TCP_FIN_WAIT2),
+	TCPF_TIME_WAIT	 = (1 << TCP_TIME_WAIT),
+	TCPF_CLOSE	 = (1 << TCP_CLOSE),
+	TCPF_CLOSE_WAIT	 = (1 << TCP_CLOSE_WAIT),
+	TCPF_LAST_ACK	 = (1 << TCP_LAST_ACK),
+	TCPF_LISTEN	 = (1 << TCP_LISTEN),
+	TCPF_CLOSING	 = (1 << TCP_CLOSING),
+	TCPF_NEW_SYN_RECV = (1 << TCP_NEW_SYN_RECV),
+	TCPF_BOUND_INACTIVE = (1 << TCP_BOUND_INACTIVE),
+};
+
+#endif	/* _LINUX_TCP_STATES_H */