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, 112 insertions, 0 deletions

diff --git a/net/mac80211/rate.h b/net/mac80211/rate.h
new file mode 100644
index 000000000..5e4bde598
--- /dev/null
+++ b/net/mac80211/rate.h
@@ -0,0 +1,112 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright 2002-2005, Instant802 Networks, Inc.
+ * Copyright 2005, Devicescape Software, Inc.
+ * Copyright (c) 2006 Jiri Benc <jbenc@suse.cz>
+ * Copyright (C) 2022, 2024 Intel Corporation
+ */
+
+#ifndef IEEE80211_RATE_H
+#define IEEE80211_RATE_H
+
+#include <linux/netdevice.h>
+#include <linux/skbuff.h>
+#include <linux/types.h>
+#include <net/mac80211.h>
+#include "ieee80211_i.h"
+#include "sta_info.h"
+#include "driver-ops.h"
+
+struct rate_control_ref {
+	const struct rate_control_ops *ops;
+	void *priv;
+};
+
+void rate_control_get_rate(struct ieee80211_sub_if_data *sdata,
+			   struct sta_info *sta,
+			   struct ieee80211_tx_rate_control *txrc);
+
+void rate_control_tx_status(struct ieee80211_local *local,
+			    struct ieee80211_tx_status *st);
+
+void rate_control_rate_init(struct link_sta_info *link_sta);
+void rate_control_rate_init_all_links(struct sta_info *sta);
+void rate_control_rate_update(struct ieee80211_local *local,
+			      struct ieee80211_supported_band *sband,
+			      struct link_sta_info *link_sta,
+			      u32 changed);
+
+static inline void *rate_control_alloc_sta(struct rate_control_ref *ref,
+					   struct sta_info *sta, gfp_t gfp)
+{
+	spin_lock_init(&sta->rate_ctrl_lock);
+	return ref->ops->alloc_sta(ref->priv, &sta->sta, gfp);
+}
+
+static inline void rate_control_free_sta(struct sta_info *sta)
+{
+	struct rate_control_ref *ref = sta->rate_ctrl;
+	struct ieee80211_sta *ista = &sta->sta;
+	void *priv_sta = sta->rate_ctrl_priv;
+
+	ref->ops->free_sta(ref->priv, ista, priv_sta);
+}
+
+static inline void rate_control_add_sta_debugfs(struct sta_info *sta)
+{
+#ifdef CONFIG_MAC80211_DEBUGFS
+	struct rate_control_ref *ref = sta->rate_ctrl;
+	if (ref && sta->debugfs_dir && ref->ops->add_sta_debugfs)
+		ref->ops->add_sta_debugfs(ref->priv, sta->rate_ctrl_priv,
+					  sta->debugfs_dir);
+#endif
+}
+
+extern const struct debugfs_short_fops rcname_ops;
+
+static inline void rate_control_add_debugfs(struct ieee80211_local *local)
+{
+#ifdef CONFIG_MAC80211_DEBUGFS
+	struct dentry *debugfsdir;
+
+	if (!local->rate_ctrl)
+		return;
+
+	if (!local->rate_ctrl->ops->add_debugfs)
+		return;
+
+	debugfsdir = debugfs_create_dir("rc", local->hw.wiphy->debugfsdir);
+	local->debugfs.rcdir = debugfsdir;
+	debugfs_create_file("name", 0400, debugfsdir,
+			    local->rate_ctrl, &rcname_ops);
+
+	local->rate_ctrl->ops->add_debugfs(&local->hw, local->rate_ctrl->priv,
+					   debugfsdir);
+#endif
+}
+
+void ieee80211_check_rate_mask(struct ieee80211_link_data *link);
+
+/* Get a reference to the rate control algorithm. If `name' is NULL, get the
+ * first available algorithm. */
+int ieee80211_init_rate_ctrl_alg(struct ieee80211_local *local,
+				 const char *name);
+void rate_control_deinitialize(struct ieee80211_local *local);
+
+
+/* Rate control algorithms */
+#ifdef CONFIG_MAC80211_RC_MINSTREL
+int rc80211_minstrel_init(void);
+void rc80211_minstrel_exit(void);
+#else
+static inline int rc80211_minstrel_init(void)
+{
+	return 0;
+}
+static inline void rc80211_minstrel_exit(void)
+{
+}
+#endif
+
+
+#endif /* IEEE80211_RATE_H */