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, 104 insertions, 0 deletions

diff --git a/drivers/crypto/qce/common.h b/drivers/crypto/qce/common.h
new file mode 100644
index 000000000..02e63ad9f
--- /dev/null
+++ b/drivers/crypto/qce/common.h
@@ -0,0 +1,104 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2010-2014, The Linux Foundation. All rights reserved.
+ */
+
+#ifndef _COMMON_H_
+#define _COMMON_H_
+
+#include <linux/crypto.h>
+#include <linux/types.h>
+#include <crypto/aes.h>
+#include <crypto/hash.h>
+#include <crypto/internal/skcipher.h>
+#include <crypto/internal/aead.h>
+
+/* xts du size */
+#define QCE_SECTOR_SIZE			512
+
+/* key size in bytes */
+#define QCE_SHA_HMAC_KEY_SIZE		64
+#define QCE_MAX_CIPHER_KEY_SIZE		AES_KEYSIZE_256
+
+/* IV length in bytes */
+#define QCE_AES_IV_LENGTH		AES_BLOCK_SIZE
+/* max of AES_BLOCK_SIZE, DES3_EDE_BLOCK_SIZE */
+#define QCE_MAX_IV_SIZE			AES_BLOCK_SIZE
+
+/* maximum nonce bytes  */
+#define QCE_MAX_NONCE			16
+#define QCE_MAX_NONCE_WORDS		(QCE_MAX_NONCE / sizeof(u32))
+
+/* burst size alignment requirement */
+#define QCE_MAX_ALIGN_SIZE		64
+
+/* cipher algorithms */
+#define QCE_ALG_DES			BIT(0)
+#define QCE_ALG_3DES			BIT(1)
+#define QCE_ALG_AES			BIT(2)
+
+/* hash and hmac algorithms */
+#define QCE_HASH_SHA1			BIT(3)
+#define QCE_HASH_SHA256			BIT(4)
+#define QCE_HASH_SHA1_HMAC		BIT(5)
+#define QCE_HASH_SHA256_HMAC		BIT(6)
+#define QCE_HASH_AES_CMAC		BIT(7)
+
+/* cipher modes */
+#define QCE_MODE_CBC			BIT(8)
+#define QCE_MODE_ECB			BIT(9)
+#define QCE_MODE_CTR			BIT(10)
+#define QCE_MODE_XTS			BIT(11)
+#define QCE_MODE_CCM			BIT(12)
+#define QCE_MODE_MASK			GENMASK(12, 8)
+
+#define QCE_MODE_CCM_RFC4309		BIT(13)
+
+/* cipher encryption/decryption operations */
+#define QCE_ENCRYPT			BIT(30)
+#define QCE_DECRYPT			BIT(31)
+
+#define IS_DES(flags)			(flags & QCE_ALG_DES)
+#define IS_3DES(flags)			(flags & QCE_ALG_3DES)
+#define IS_AES(flags)			(flags & QCE_ALG_AES)
+
+#define IS_SHA1(flags)			(flags & QCE_HASH_SHA1)
+#define IS_SHA256(flags)		(flags & QCE_HASH_SHA256)
+#define IS_SHA1_HMAC(flags)		(flags & QCE_HASH_SHA1_HMAC)
+#define IS_SHA256_HMAC(flags)		(flags & QCE_HASH_SHA256_HMAC)
+#define IS_CMAC(flags)			(flags & QCE_HASH_AES_CMAC)
+#define IS_SHA(flags)			(IS_SHA1(flags) || IS_SHA256(flags))
+#define IS_SHA_HMAC(flags)		\
+		(IS_SHA1_HMAC(flags) || IS_SHA256_HMAC(flags))
+
+#define IS_CBC(mode)			(mode & QCE_MODE_CBC)
+#define IS_ECB(mode)			(mode & QCE_MODE_ECB)
+#define IS_CTR(mode)			(mode & QCE_MODE_CTR)
+#define IS_XTS(mode)			(mode & QCE_MODE_XTS)
+#define IS_CCM(mode)			(mode & QCE_MODE_CCM)
+#define IS_CCM_RFC4309(mode)		((mode) & QCE_MODE_CCM_RFC4309)
+
+#define IS_ENCRYPT(dir)			(dir & QCE_ENCRYPT)
+#define IS_DECRYPT(dir)			(dir & QCE_DECRYPT)
+
+struct qce_alg_template {
+	struct list_head entry;
+	u32 crypto_alg_type;
+	unsigned long alg_flags;
+	const u32 *std_iv;
+	union {
+		struct skcipher_alg skcipher;
+		struct ahash_alg ahash;
+		struct aead_alg aead;
+	} alg;
+	struct qce_device *qce;
+	const u8 *hash_zero;
+	const u32 digest_size;
+};
+
+void qce_cpu_to_be32p_array(__be32 *dst, const u8 *src, unsigned int len);
+int qce_check_status(struct qce_device *qce, u32 *status);
+void qce_get_version(struct qce_device *qce, u32 *major, u32 *minor, u32 *step);
+int qce_start(struct crypto_async_request *async_req, u32 type);
+
+#endif /* _COMMON_H_ */