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, 89 insertions, 0 deletions

diff --git a/drivers/remoteproc/qcom_common.h b/drivers/remoteproc/qcom_common.h
new file mode 100644
index 000000000..b07fbaa09
--- /dev/null
+++ b/drivers/remoteproc/qcom_common.h
@@ -0,0 +1,89 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __RPROC_QCOM_COMMON_H__
+#define __RPROC_QCOM_COMMON_H__
+
+#include <linux/remoteproc.h>
+#include "remoteproc_internal.h"
+#include <linux/soc/qcom/qmi.h>
+
+struct qcom_glink_smem;
+struct qcom_sysmon;
+
+struct qcom_rproc_glink {
+	struct rproc_subdev subdev;
+
+	const char *ssr_name;
+
+	struct device *dev;
+	struct device_node *node;
+	struct qcom_glink_smem *edge;
+};
+
+struct qcom_rproc_subdev {
+	struct rproc_subdev subdev;
+
+	struct device *dev;
+	struct device_node *node;
+	struct qcom_smd_edge *edge;
+};
+
+struct qcom_ssr_subsystem;
+
+struct qcom_rproc_ssr {
+	struct rproc_subdev subdev;
+	struct qcom_ssr_subsystem *info;
+};
+
+struct qcom_rproc_pdm {
+	struct rproc_subdev subdev;
+	struct device *dev;
+	int index;
+	struct auxiliary_device *adev;
+};
+
+void qcom_minidump(struct rproc *rproc, unsigned int minidump_id,
+			void (*rproc_dumpfn_t)(struct rproc *rproc,
+				struct rproc_dump_segment *segment, void *dest, size_t offset,
+				size_t size));
+
+void qcom_add_glink_subdev(struct rproc *rproc, struct qcom_rproc_glink *glink,
+			   const char *ssr_name);
+void qcom_remove_glink_subdev(struct rproc *rproc, struct qcom_rproc_glink *glink);
+
+int qcom_register_dump_segments(struct rproc *rproc, const struct firmware *fw);
+
+void qcom_add_smd_subdev(struct rproc *rproc, struct qcom_rproc_subdev *smd);
+void qcom_remove_smd_subdev(struct rproc *rproc, struct qcom_rproc_subdev *smd);
+
+void qcom_add_ssr_subdev(struct rproc *rproc, struct qcom_rproc_ssr *ssr,
+			 const char *ssr_name);
+void qcom_remove_ssr_subdev(struct rproc *rproc, struct qcom_rproc_ssr *ssr);
+
+void qcom_add_pdm_subdev(struct rproc *rproc, struct qcom_rproc_pdm *pdm);
+void qcom_remove_pdm_subdev(struct rproc *rproc, struct qcom_rproc_pdm *pdm);
+
+#if IS_ENABLED(CONFIG_QCOM_SYSMON)
+struct qcom_sysmon *qcom_add_sysmon_subdev(struct rproc *rproc,
+					   const char *name,
+					   int ssctl_instance);
+void qcom_remove_sysmon_subdev(struct qcom_sysmon *sysmon);
+bool qcom_sysmon_shutdown_acked(struct qcom_sysmon *sysmon);
+#else
+static inline struct qcom_sysmon *qcom_add_sysmon_subdev(struct rproc *rproc,
+							 const char *name,
+							 int ssctl_instance)
+{
+	return NULL;
+}
+
+static inline void qcom_remove_sysmon_subdev(struct qcom_sysmon *sysmon)
+{
+}
+
+static inline bool qcom_sysmon_shutdown_acked(struct qcom_sysmon *sysmon)
+{
+	return false;
+}
+#endif
+
+#endif