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, 447 insertions, 0 deletions

diff --git a/net/dsa/trace.h b/net/dsa/trace.h
new file mode 100644
index 000000000..83f3e5f78
--- /dev/null
+++ b/net/dsa/trace.h
@@ -0,0 +1,447 @@
+/* SPDX-License-Identifier: GPL-2.0
+ * Copyright 2022-2023 NXP
+ */
+
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM	dsa
+
+#if !defined(_NET_DSA_TRACE_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _NET_DSA_TRACE_H
+
+#include <net/dsa.h>
+#include <net/switchdev.h>
+#include <linux/etherdevice.h>
+#include <linux/if_bridge.h>
+#include <linux/refcount.h>
+#include <linux/tracepoint.h>
+
+/* Enough to fit "bridge %s num %d" where num has 3 digits */
+#define DSA_DB_BUFSIZ	(IFNAMSIZ + 16)
+
+void dsa_db_print(const struct dsa_db *db, char buf[DSA_DB_BUFSIZ]);
+const char *dsa_port_kind(const struct dsa_port *dp);
+
+DECLARE_EVENT_CLASS(dsa_port_addr_op_hw,
+
+	TP_PROTO(const struct dsa_port *dp, const unsigned char *addr, u16 vid,
+		 const struct dsa_db *db, int err),
+
+	TP_ARGS(dp, addr, vid, db, err),
+
+	TP_STRUCT__entry(
+		__string(dev, dev_name(dp->ds->dev))
+		__string(kind, dsa_port_kind(dp))
+		__field(int, port)
+		__array(unsigned char, addr, ETH_ALEN)
+		__field(u16, vid)
+		__array(char, db_buf, DSA_DB_BUFSIZ)
+		__field(int, err)
+	),
+
+	TP_fast_assign(
+		__assign_str(dev);
+		__assign_str(kind);
+		__entry->port = dp->index;
+		ether_addr_copy(__entry->addr, addr);
+		__entry->vid = vid;
+		dsa_db_print(db, __entry->db_buf);
+		__entry->err = err;
+	),
+
+	TP_printk("%s %s port %d addr %pM vid %u db \"%s\" err %d",
+		  __get_str(dev), __get_str(kind), __entry->port, __entry->addr,
+		  __entry->vid, __entry->db_buf, __entry->err)
+);
+
+/* Add unicast/multicast address to hardware, either on user ports
+ * (where no refcounting is kept), or on shared ports when the entry
+ * is first seen and its refcount is 1.
+ */
+DEFINE_EVENT(dsa_port_addr_op_hw, dsa_fdb_add_hw,
+	     TP_PROTO(const struct dsa_port *dp, const unsigned char *addr,
+		      u16 vid, const struct dsa_db *db, int err),
+	     TP_ARGS(dp, addr, vid, db, err));
+
+DEFINE_EVENT(dsa_port_addr_op_hw, dsa_mdb_add_hw,
+	     TP_PROTO(const struct dsa_port *dp, const unsigned char *addr,
+		      u16 vid, const struct dsa_db *db, int err),
+	     TP_ARGS(dp, addr, vid, db, err));
+
+/* Delete unicast/multicast address from hardware, either on user ports or
+ * when the refcount on shared ports reaches 0
+ */
+DEFINE_EVENT(dsa_port_addr_op_hw, dsa_fdb_del_hw,
+	     TP_PROTO(const struct dsa_port *dp, const unsigned char *addr,
+		      u16 vid, const struct dsa_db *db, int err),
+	     TP_ARGS(dp, addr, vid, db, err));
+
+DEFINE_EVENT(dsa_port_addr_op_hw, dsa_mdb_del_hw,
+	     TP_PROTO(const struct dsa_port *dp, const unsigned char *addr,
+		      u16 vid, const struct dsa_db *db, int err),
+	     TP_ARGS(dp, addr, vid, db, err));
+
+DECLARE_EVENT_CLASS(dsa_port_addr_op_refcount,
+
+	TP_PROTO(const struct dsa_port *dp, const unsigned char *addr, u16 vid,
+		 const struct dsa_db *db, const refcount_t *refcount),
+
+	TP_ARGS(dp, addr, vid, db, refcount),
+
+	TP_STRUCT__entry(
+		__string(dev, dev_name(dp->ds->dev))
+		__string(kind, dsa_port_kind(dp))
+		__field(int, port)
+		__array(unsigned char, addr, ETH_ALEN)
+		__field(u16, vid)
+		__array(char, db_buf, DSA_DB_BUFSIZ)
+		__field(unsigned int, refcount)
+	),
+
+	TP_fast_assign(
+		__assign_str(dev);
+		__assign_str(kind);
+		__entry->port = dp->index;
+		ether_addr_copy(__entry->addr, addr);
+		__entry->vid = vid;
+		dsa_db_print(db, __entry->db_buf);
+		__entry->refcount = refcount_read(refcount);
+	),
+
+	TP_printk("%s %s port %d addr %pM vid %u db \"%s\" refcount %u",
+		  __get_str(dev), __get_str(kind), __entry->port, __entry->addr,
+		  __entry->vid, __entry->db_buf, __entry->refcount)
+);
+
+/* Bump the refcount of an existing unicast/multicast address on shared ports */
+DEFINE_EVENT(dsa_port_addr_op_refcount, dsa_fdb_add_bump,
+	     TP_PROTO(const struct dsa_port *dp, const unsigned char *addr,
+		      u16 vid, const struct dsa_db *db,
+		      const refcount_t *refcount),
+	     TP_ARGS(dp, addr, vid, db, refcount));
+
+DEFINE_EVENT(dsa_port_addr_op_refcount, dsa_mdb_add_bump,
+	     TP_PROTO(const struct dsa_port *dp, const unsigned char *addr,
+		      u16 vid, const struct dsa_db *db,
+		      const refcount_t *refcount),
+	     TP_ARGS(dp, addr, vid, db, refcount));
+
+/* Drop the refcount of a multicast address that we still keep on
+ * shared ports
+ */
+DEFINE_EVENT(dsa_port_addr_op_refcount, dsa_fdb_del_drop,
+	     TP_PROTO(const struct dsa_port *dp, const unsigned char *addr,
+		      u16 vid, const struct dsa_db *db,
+		      const refcount_t *refcount),
+	     TP_ARGS(dp, addr, vid, db, refcount));
+
+DEFINE_EVENT(dsa_port_addr_op_refcount, dsa_mdb_del_drop,
+	     TP_PROTO(const struct dsa_port *dp, const unsigned char *addr,
+		      u16 vid, const struct dsa_db *db,
+		      const refcount_t *refcount),
+	     TP_ARGS(dp, addr, vid, db, refcount));
+
+DECLARE_EVENT_CLASS(dsa_port_addr_del_not_found,
+
+	TP_PROTO(const struct dsa_port *dp, const unsigned char *addr, u16 vid,
+		 const struct dsa_db *db),
+
+	TP_ARGS(dp, addr, vid, db),
+
+	TP_STRUCT__entry(
+		__string(dev, dev_name(dp->ds->dev))
+		__string(kind, dsa_port_kind(dp))
+		__field(int, port)
+		__array(unsigned char, addr, ETH_ALEN)
+		__field(u16, vid)
+		__array(char, db_buf, DSA_DB_BUFSIZ)
+	),
+
+	TP_fast_assign(
+		__assign_str(dev);
+		__assign_str(kind);
+		__entry->port = dp->index;
+		ether_addr_copy(__entry->addr, addr);
+		__entry->vid = vid;
+		dsa_db_print(db, __entry->db_buf);
+	),
+
+	TP_printk("%s %s port %d addr %pM vid %u db \"%s\"",
+		  __get_str(dev), __get_str(kind), __entry->port,
+		  __entry->addr, __entry->vid, __entry->db_buf)
+);
+
+/* Attempt to delete a unicast/multicast address on shared ports for which
+ * the delete operation was called more times than the addition
+ */
+DEFINE_EVENT(dsa_port_addr_del_not_found, dsa_fdb_del_not_found,
+	     TP_PROTO(const struct dsa_port *dp, const unsigned char *addr,
+		      u16 vid, const struct dsa_db *db),
+	     TP_ARGS(dp, addr, vid, db));
+
+DEFINE_EVENT(dsa_port_addr_del_not_found, dsa_mdb_del_not_found,
+	     TP_PROTO(const struct dsa_port *dp, const unsigned char *addr,
+		      u16 vid, const struct dsa_db *db),
+	     TP_ARGS(dp, addr, vid, db));
+
+TRACE_EVENT(dsa_lag_fdb_add_hw,
+
+	TP_PROTO(const struct net_device *lag_dev, const unsigned char *addr,
+		 u16 vid, const struct dsa_db *db, int err),
+
+	TP_ARGS(lag_dev, addr, vid, db, err),
+
+	TP_STRUCT__entry(
+		__string(dev, lag_dev->name)
+		__array(unsigned char, addr, ETH_ALEN)
+		__field(u16, vid)
+		__array(char, db_buf, DSA_DB_BUFSIZ)
+		__field(int, err)
+	),
+
+	TP_fast_assign(
+		__assign_str(dev);
+		ether_addr_copy(__entry->addr, addr);
+		__entry->vid = vid;
+		dsa_db_print(db, __entry->db_buf);
+		__entry->err = err;
+	),
+
+	TP_printk("%s addr %pM vid %u db \"%s\" err %d",
+		  __get_str(dev), __entry->addr, __entry->vid,
+		  __entry->db_buf, __entry->err)
+);
+
+TRACE_EVENT(dsa_lag_fdb_add_bump,
+
+	TP_PROTO(const struct net_device *lag_dev, const unsigned char *addr,
+		 u16 vid, const struct dsa_db *db, const refcount_t *refcount),
+
+	TP_ARGS(lag_dev, addr, vid, db, refcount),
+
+	TP_STRUCT__entry(
+		__string(dev, lag_dev->name)
+		__array(unsigned char, addr, ETH_ALEN)
+		__field(u16, vid)
+		__array(char, db_buf, DSA_DB_BUFSIZ)
+		__field(unsigned int, refcount)
+	),
+
+	TP_fast_assign(
+		__assign_str(dev);
+		ether_addr_copy(__entry->addr, addr);
+		__entry->vid = vid;
+		dsa_db_print(db, __entry->db_buf);
+		__entry->refcount = refcount_read(refcount);
+	),
+
+	TP_printk("%s addr %pM vid %u db \"%s\" refcount %u",
+		  __get_str(dev), __entry->addr, __entry->vid,
+		  __entry->db_buf, __entry->refcount)
+);
+
+TRACE_EVENT(dsa_lag_fdb_del_hw,
+
+	TP_PROTO(const struct net_device *lag_dev, const unsigned char *addr,
+		 u16 vid, const struct dsa_db *db, int err),
+
+	TP_ARGS(lag_dev, addr, vid, db, err),
+
+	TP_STRUCT__entry(
+		__string(dev, lag_dev->name)
+		__array(unsigned char, addr, ETH_ALEN)
+		__field(u16, vid)
+		__array(char, db_buf, DSA_DB_BUFSIZ)
+		__field(int, err)
+	),
+
+	TP_fast_assign(
+		__assign_str(dev);
+		ether_addr_copy(__entry->addr, addr);
+		__entry->vid = vid;
+		dsa_db_print(db, __entry->db_buf);
+		__entry->err = err;
+	),
+
+	TP_printk("%s addr %pM vid %u db \"%s\" err %d",
+		  __get_str(dev), __entry->addr, __entry->vid,
+		  __entry->db_buf, __entry->err)
+);
+
+TRACE_EVENT(dsa_lag_fdb_del_drop,
+
+	TP_PROTO(const struct net_device *lag_dev, const unsigned char *addr,
+		 u16 vid, const struct dsa_db *db, const refcount_t *refcount),
+
+	TP_ARGS(lag_dev, addr, vid, db, refcount),
+
+	TP_STRUCT__entry(
+		__string(dev, lag_dev->name)
+		__array(unsigned char, addr, ETH_ALEN)
+		__field(u16, vid)
+		__array(char, db_buf, DSA_DB_BUFSIZ)
+		__field(unsigned int, refcount)
+	),
+
+	TP_fast_assign(
+		__assign_str(dev);
+		ether_addr_copy(__entry->addr, addr);
+		__entry->vid = vid;
+		dsa_db_print(db, __entry->db_buf);
+		__entry->refcount = refcount_read(refcount);
+	),
+
+	TP_printk("%s addr %pM vid %u db \"%s\" refcount %u",
+		  __get_str(dev), __entry->addr, __entry->vid,
+		  __entry->db_buf, __entry->refcount)
+);
+
+TRACE_EVENT(dsa_lag_fdb_del_not_found,
+
+	TP_PROTO(const struct net_device *lag_dev, const unsigned char *addr,
+		 u16 vid, const struct dsa_db *db),
+
+	TP_ARGS(lag_dev, addr, vid, db),
+
+	TP_STRUCT__entry(
+		__string(dev, lag_dev->name)
+		__array(unsigned char, addr, ETH_ALEN)
+		__field(u16, vid)
+		__array(char, db_buf, DSA_DB_BUFSIZ)
+	),
+
+	TP_fast_assign(
+		__assign_str(dev);
+		ether_addr_copy(__entry->addr, addr);
+		__entry->vid = vid;
+		dsa_db_print(db, __entry->db_buf);
+	),
+
+	TP_printk("%s addr %pM vid %u db \"%s\"",
+		  __get_str(dev), __entry->addr, __entry->vid, __entry->db_buf)
+);
+
+DECLARE_EVENT_CLASS(dsa_vlan_op_hw,
+
+	TP_PROTO(const struct dsa_port *dp,
+		 const struct switchdev_obj_port_vlan *vlan, int err),
+
+	TP_ARGS(dp, vlan, err),
+
+	TP_STRUCT__entry(
+		__string(dev, dev_name(dp->ds->dev))
+		__string(kind, dsa_port_kind(dp))
+		__field(int, port)
+		__field(u16, vid)
+		__field(u16, flags)
+		__field(bool, changed)
+		__field(int, err)
+	),
+
+	TP_fast_assign(
+		__assign_str(dev);
+		__assign_str(kind);
+		__entry->port = dp->index;
+		__entry->vid = vlan->vid;
+		__entry->flags = vlan->flags;
+		__entry->changed = vlan->changed;
+		__entry->err = err;
+	),
+
+	TP_printk("%s %s port %d vid %u%s%s%s",
+		  __get_str(dev), __get_str(kind), __entry->port, __entry->vid,
+		  __entry->flags & BRIDGE_VLAN_INFO_PVID ? " pvid" : "",
+		  __entry->flags & BRIDGE_VLAN_INFO_UNTAGGED ? " untagged" : "",
+		  __entry->changed ? " (changed)" : "")
+);
+
+DEFINE_EVENT(dsa_vlan_op_hw, dsa_vlan_add_hw,
+	     TP_PROTO(const struct dsa_port *dp,
+		      const struct switchdev_obj_port_vlan *vlan, int err),
+	     TP_ARGS(dp, vlan, err));
+
+DEFINE_EVENT(dsa_vlan_op_hw, dsa_vlan_del_hw,
+	     TP_PROTO(const struct dsa_port *dp,
+		      const struct switchdev_obj_port_vlan *vlan, int err),
+	     TP_ARGS(dp, vlan, err));
+
+DECLARE_EVENT_CLASS(dsa_vlan_op_refcount,
+
+	TP_PROTO(const struct dsa_port *dp,
+		 const struct switchdev_obj_port_vlan *vlan,
+		 const refcount_t *refcount),
+
+	TP_ARGS(dp, vlan, refcount),
+
+	TP_STRUCT__entry(
+		__string(dev, dev_name(dp->ds->dev))
+		__string(kind, dsa_port_kind(dp))
+		__field(int, port)
+		__field(u16, vid)
+		__field(u16, flags)
+		__field(bool, changed)
+		__field(unsigned int, refcount)
+	),
+
+	TP_fast_assign(
+		__assign_str(dev);
+		__assign_str(kind);
+		__entry->port = dp->index;
+		__entry->vid = vlan->vid;
+		__entry->flags = vlan->flags;
+		__entry->changed = vlan->changed;
+		__entry->refcount = refcount_read(refcount);
+	),
+
+	TP_printk("%s %s port %d vid %u%s%s%s refcount %u",
+		  __get_str(dev), __get_str(kind), __entry->port, __entry->vid,
+		  __entry->flags & BRIDGE_VLAN_INFO_PVID ? " pvid" : "",
+		  __entry->flags & BRIDGE_VLAN_INFO_UNTAGGED ? " untagged" : "",
+		  __entry->changed ? " (changed)" : "", __entry->refcount)
+);
+
+DEFINE_EVENT(dsa_vlan_op_refcount, dsa_vlan_add_bump,
+	     TP_PROTO(const struct dsa_port *dp,
+		      const struct switchdev_obj_port_vlan *vlan,
+		      const refcount_t *refcount),
+	     TP_ARGS(dp, vlan, refcount));
+
+DEFINE_EVENT(dsa_vlan_op_refcount, dsa_vlan_del_drop,
+	     TP_PROTO(const struct dsa_port *dp,
+		      const struct switchdev_obj_port_vlan *vlan,
+		      const refcount_t *refcount),
+	     TP_ARGS(dp, vlan, refcount));
+
+TRACE_EVENT(dsa_vlan_del_not_found,
+
+	TP_PROTO(const struct dsa_port *dp,
+		 const struct switchdev_obj_port_vlan *vlan),
+
+	TP_ARGS(dp, vlan),
+
+	TP_STRUCT__entry(
+		__string(dev, dev_name(dp->ds->dev))
+		__string(kind, dsa_port_kind(dp))
+		__field(int, port)
+		__field(u16, vid)
+	),
+
+	TP_fast_assign(
+		__assign_str(dev);
+		__assign_str(kind);
+		__entry->port = dp->index;
+		__entry->vid = vlan->vid;
+	),
+
+	TP_printk("%s %s port %d vid %u",
+		  __get_str(dev), __get_str(kind), __entry->port, __entry->vid)
+);
+
+#endif /* _NET_DSA_TRACE_H */
+
+/* We don't want to use include/trace/events */
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH .
+#undef TRACE_INCLUDE_FILE
+#define TRACE_INCLUDE_FILE	trace
+/* This part must be outside protection */
+#include <trace/define_trace.h>