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, 354 insertions, 0 deletions

diff --git a/net/mac802154/driver-ops.h b/net/mac802154/driver-ops.h
new file mode 100644
index 000000000..a7af3f0dd
--- /dev/null
+++ b/net/mac802154/driver-ops.h
@@ -0,0 +1,354 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __MAC802154_DRIVER_OPS
+#define __MAC802154_DRIVER_OPS
+
+#include <linux/types.h>
+#include <linux/rtnetlink.h>
+
+#include <net/mac802154.h>
+
+#include "ieee802154_i.h"
+#include "trace.h"
+
+static inline int
+drv_xmit_async(struct ieee802154_local *local, struct sk_buff *skb)
+{
+	return local->ops->xmit_async(&local->hw, skb);
+}
+
+static inline int
+drv_xmit_sync(struct ieee802154_local *local, struct sk_buff *skb)
+{
+	might_sleep();
+
+	return local->ops->xmit_sync(&local->hw, skb);
+}
+
+static inline int drv_set_pan_id(struct ieee802154_local *local, __le16 pan_id)
+{
+	struct ieee802154_hw_addr_filt filt;
+	int ret;
+
+	might_sleep();
+
+	if (!local->ops->set_hw_addr_filt) {
+		WARN_ON(1);
+		return -EOPNOTSUPP;
+	}
+
+	filt.pan_id = pan_id;
+
+	trace_802154_drv_set_pan_id(local, pan_id);
+	ret = local->ops->set_hw_addr_filt(&local->hw, &filt,
+					    IEEE802154_AFILT_PANID_CHANGED);
+	trace_802154_drv_return_int(local, ret);
+	return ret;
+}
+
+static inline int
+drv_set_extended_addr(struct ieee802154_local *local, __le64 extended_addr)
+{
+	struct ieee802154_hw_addr_filt filt;
+	int ret;
+
+	might_sleep();
+
+	if (!local->ops->set_hw_addr_filt) {
+		WARN_ON(1);
+		return -EOPNOTSUPP;
+	}
+
+	filt.ieee_addr = extended_addr;
+
+	trace_802154_drv_set_extended_addr(local, extended_addr);
+	ret = local->ops->set_hw_addr_filt(&local->hw, &filt,
+					    IEEE802154_AFILT_IEEEADDR_CHANGED);
+	trace_802154_drv_return_int(local, ret);
+	return ret;
+}
+
+static inline int
+drv_set_short_addr(struct ieee802154_local *local, __le16 short_addr)
+{
+	struct ieee802154_hw_addr_filt filt;
+	int ret;
+
+	might_sleep();
+
+	if (!local->ops->set_hw_addr_filt) {
+		WARN_ON(1);
+		return -EOPNOTSUPP;
+	}
+
+	filt.short_addr = short_addr;
+
+	trace_802154_drv_set_short_addr(local, short_addr);
+	ret = local->ops->set_hw_addr_filt(&local->hw, &filt,
+					    IEEE802154_AFILT_SADDR_CHANGED);
+	trace_802154_drv_return_int(local, ret);
+	return ret;
+}
+
+static inline int
+drv_set_pan_coord(struct ieee802154_local *local, bool is_coord)
+{
+	struct ieee802154_hw_addr_filt filt;
+	int ret;
+
+	might_sleep();
+
+	if (!local->ops->set_hw_addr_filt) {
+		WARN_ON(1);
+		return -EOPNOTSUPP;
+	}
+
+	filt.pan_coord = is_coord;
+
+	trace_802154_drv_set_pan_coord(local, is_coord);
+	ret = local->ops->set_hw_addr_filt(&local->hw, &filt,
+					    IEEE802154_AFILT_PANC_CHANGED);
+	trace_802154_drv_return_int(local, ret);
+	return ret;
+}
+
+static inline int
+drv_set_promiscuous_mode(struct ieee802154_local *local, bool on)
+{
+	int ret;
+
+	might_sleep();
+
+	if (!local->ops->set_promiscuous_mode) {
+		WARN_ON(1);
+		return -EOPNOTSUPP;
+	}
+
+	trace_802154_drv_set_promiscuous_mode(local, on);
+	ret = local->ops->set_promiscuous_mode(&local->hw, on);
+	trace_802154_drv_return_int(local, ret);
+	return ret;
+}
+
+static inline int drv_start(struct ieee802154_local *local,
+			    enum ieee802154_filtering_level level,
+			    const struct ieee802154_hw_addr_filt *addr_filt)
+{
+	int ret;
+
+	might_sleep();
+
+	/* setup receive mode parameters e.g. address mode */
+	if (local->hw.flags & IEEE802154_HW_AFILT) {
+		ret = drv_set_pan_id(local, addr_filt->pan_id);
+		if (ret < 0)
+			return ret;
+
+		ret = drv_set_short_addr(local, addr_filt->short_addr);
+		if (ret < 0)
+			return ret;
+
+		ret = drv_set_extended_addr(local, addr_filt->ieee_addr);
+		if (ret < 0)
+			return ret;
+	}
+
+	switch (level) {
+	case IEEE802154_FILTERING_NONE:
+		fallthrough;
+	case IEEE802154_FILTERING_1_FCS:
+		fallthrough;
+	case IEEE802154_FILTERING_2_PROMISCUOUS:
+		/* TODO: Requires a different receive mode setup e.g.
+		 * at86rf233 hardware.
+		 */
+		fallthrough;
+	case IEEE802154_FILTERING_3_SCAN:
+		if (local->hw.flags & IEEE802154_HW_PROMISCUOUS) {
+			ret = drv_set_promiscuous_mode(local, true);
+			if (ret < 0)
+				return ret;
+		} else {
+			return -EOPNOTSUPP;
+		}
+
+		/* In practice other filtering levels can be requested, but as
+		 * for now most hardware/drivers only support
+		 * IEEE802154_FILTERING_NONE, we fallback to this actual
+		 * filtering level in hardware and make our own additional
+		 * filtering in mac802154 receive path.
+		 *
+		 * TODO: Move this logic to the device drivers as hardware may
+		 * support more higher level filters. Hardware may also require
+		 * a different order how register are set, which could currently
+		 * be buggy, so all received parameters need to be moved to the
+		 * start() callback and let the driver go into the mode before
+		 * it will turn on receive handling.
+		 */
+		local->phy->filtering = IEEE802154_FILTERING_NONE;
+		break;
+	case IEEE802154_FILTERING_4_FRAME_FIELDS:
+		/* Do not error out if IEEE802154_HW_PROMISCUOUS because we
+		 * expect the hardware to operate at the level
+		 * IEEE802154_FILTERING_4_FRAME_FIELDS anyway.
+		 */
+		if (local->hw.flags & IEEE802154_HW_PROMISCUOUS) {
+			ret = drv_set_promiscuous_mode(local, false);
+			if (ret < 0)
+				return ret;
+		}
+
+		local->phy->filtering = IEEE802154_FILTERING_4_FRAME_FIELDS;
+		break;
+	default:
+		WARN_ON(1);
+		return -EINVAL;
+	}
+
+	trace_802154_drv_start(local);
+	local->started = true;
+	smp_mb();
+	ret = local->ops->start(&local->hw);
+	trace_802154_drv_return_int(local, ret);
+	return ret;
+}
+
+static inline void drv_stop(struct ieee802154_local *local)
+{
+	might_sleep();
+
+	trace_802154_drv_stop(local);
+	local->ops->stop(&local->hw);
+	trace_802154_drv_return_void(local);
+
+	/* sync away all work on the tasklet before clearing started */
+	tasklet_disable(&local->tasklet);
+	tasklet_enable(&local->tasklet);
+
+	barrier();
+
+	local->started = false;
+}
+
+static inline int
+drv_set_channel(struct ieee802154_local *local, u8 page, u8 channel)
+{
+	int ret;
+
+	might_sleep();
+
+	trace_802154_drv_set_channel(local, page, channel);
+	ret = local->ops->set_channel(&local->hw, page, channel);
+	trace_802154_drv_return_int(local, ret);
+	return ret;
+}
+
+static inline int drv_set_tx_power(struct ieee802154_local *local, s32 mbm)
+{
+	int ret;
+
+	might_sleep();
+
+	if (!local->ops->set_txpower) {
+		WARN_ON(1);
+		return -EOPNOTSUPP;
+	}
+
+	trace_802154_drv_set_tx_power(local, mbm);
+	ret = local->ops->set_txpower(&local->hw, mbm);
+	trace_802154_drv_return_int(local, ret);
+	return ret;
+}
+
+static inline int drv_set_cca_mode(struct ieee802154_local *local,
+				   const struct wpan_phy_cca *cca)
+{
+	int ret;
+
+	might_sleep();
+
+	if (!local->ops->set_cca_mode) {
+		WARN_ON(1);
+		return -EOPNOTSUPP;
+	}
+
+	trace_802154_drv_set_cca_mode(local, cca);
+	ret = local->ops->set_cca_mode(&local->hw, cca);
+	trace_802154_drv_return_int(local, ret);
+	return ret;
+}
+
+static inline int drv_set_lbt_mode(struct ieee802154_local *local, bool mode)
+{
+	int ret;
+
+	might_sleep();
+
+	if (!local->ops->set_lbt) {
+		WARN_ON(1);
+		return -EOPNOTSUPP;
+	}
+
+	trace_802154_drv_set_lbt_mode(local, mode);
+	ret = local->ops->set_lbt(&local->hw, mode);
+	trace_802154_drv_return_int(local, ret);
+	return ret;
+}
+
+static inline int
+drv_set_cca_ed_level(struct ieee802154_local *local, s32 mbm)
+{
+	int ret;
+
+	might_sleep();
+
+	if (!local->ops->set_cca_ed_level) {
+		WARN_ON(1);
+		return -EOPNOTSUPP;
+	}
+
+	trace_802154_drv_set_cca_ed_level(local, mbm);
+	ret = local->ops->set_cca_ed_level(&local->hw, mbm);
+	trace_802154_drv_return_int(local, ret);
+	return ret;
+}
+
+static inline int
+drv_set_csma_params(struct ieee802154_local *local, u8 min_be, u8 max_be,
+		    u8 max_csma_backoffs)
+{
+	int ret;
+
+	might_sleep();
+
+	if (!local->ops->set_csma_params) {
+		WARN_ON(1);
+		return -EOPNOTSUPP;
+	}
+
+	trace_802154_drv_set_csma_params(local, min_be, max_be,
+					 max_csma_backoffs);
+	ret = local->ops->set_csma_params(&local->hw, min_be, max_be,
+					   max_csma_backoffs);
+	trace_802154_drv_return_int(local, ret);
+	return ret;
+}
+
+static inline int
+drv_set_max_frame_retries(struct ieee802154_local *local, s8 max_frame_retries)
+{
+	int ret;
+
+	might_sleep();
+
+	if (!local->ops->set_frame_retries) {
+		WARN_ON(1);
+		return -EOPNOTSUPP;
+	}
+
+	trace_802154_drv_set_max_frame_retries(local, max_frame_retries);
+	ret = local->ops->set_frame_retries(&local->hw, max_frame_retries);
+	trace_802154_drv_return_int(local, ret);
+	return ret;
+}
+
+#endif /* __MAC802154_DRIVER_OPS */