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, 52 insertions, 0 deletions

diff --git a/drivers/crypto/caam/compat.h b/drivers/crypto/caam/compat.h
new file mode 100644
index 000000000..c4f797641
--- /dev/null
+++ b/drivers/crypto/caam/compat.h
@@ -0,0 +1,52 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright 2008-2011 Freescale Semiconductor, Inc.
+ */
+
+#ifndef CAAM_COMPAT_H
+#define CAAM_COMPAT_H
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/device.h>
+#include <linux/interrupt.h>
+#include <linux/crypto.h>
+#include <linux/hash.h>
+#include <linux/hw_random.h>
+#include <linux/of_platform.h>
+#include <linux/dma-mapping.h>
+#include <linux/io.h>
+#include <linux/iommu.h>
+#include <linux/spinlock.h>
+#include <linux/rtnetlink.h>
+#include <linux/in.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/debugfs.h>
+#include <linux/circ_buf.h>
+#include <linux/clk.h>
+#include <net/xfrm.h>
+
+#include <crypto/algapi.h>
+#include <crypto/null.h>
+#include <crypto/aes.h>
+#include <crypto/ctr.h>
+#include <crypto/internal/des.h>
+#include <crypto/gcm.h>
+#include <crypto/sha1.h>
+#include <crypto/sha2.h>
+#include <crypto/md5.h>
+#include <crypto/chacha.h>
+#include <crypto/poly1305.h>
+#include <crypto/internal/aead.h>
+#include <crypto/authenc.h>
+#include <crypto/akcipher.h>
+#include <crypto/scatterwalk.h>
+#include <crypto/skcipher.h>
+#include <crypto/internal/skcipher.h>
+#include <crypto/internal/hash.h>
+#include <crypto/internal/rsa.h>
+#include <crypto/internal/akcipher.h>
+
+#endif /* !defined(CAAM_COMPAT_H) */