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, 247 insertions, 0 deletions

diff --git a/crypto/krb5/internal.h b/crypto/krb5/internal.h
new file mode 100644
index 000000000..a59084ffa
--- /dev/null
+++ b/crypto/krb5/internal.h
@@ -0,0 +1,247 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/* Kerberos5 crypto internals
+ *
+ * Copyright (C) 2025 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#include <linux/scatterlist.h>
+#include <crypto/krb5.h>
+#include <crypto/hash.h>
+#include <crypto/skcipher.h>
+
+/*
+ * Profile used for key derivation and encryption.
+ */
+struct krb5_crypto_profile {
+	 /* Pseudo-random function */
+	int (*calc_PRF)(const struct krb5_enctype *krb5,
+			const struct krb5_buffer *protocol_key,
+			const struct krb5_buffer *octet_string,
+			struct krb5_buffer *result,
+			gfp_t gfp);
+
+	/* Checksum key derivation */
+	int (*calc_Kc)(const struct krb5_enctype *krb5,
+		       const struct krb5_buffer *TK,
+		       const struct krb5_buffer *usage_constant,
+		       struct krb5_buffer *Kc,
+		       gfp_t gfp);
+
+	/* Encryption key derivation */
+	int (*calc_Ke)(const struct krb5_enctype *krb5,
+		       const struct krb5_buffer *TK,
+		       const struct krb5_buffer *usage_constant,
+		       struct krb5_buffer *Ke,
+		       gfp_t gfp);
+
+	 /* Integrity key derivation */
+	int (*calc_Ki)(const struct krb5_enctype *krb5,
+		       const struct krb5_buffer *TK,
+		       const struct krb5_buffer *usage_constant,
+		       struct krb5_buffer *Ki,
+		       gfp_t gfp);
+
+	/* Derive the keys needed for an encryption AEAD object. */
+	int (*derive_encrypt_keys)(const struct krb5_enctype *krb5,
+				   const struct krb5_buffer *TK,
+				   unsigned int usage,
+				   struct krb5_buffer *setkey,
+				   gfp_t gfp);
+
+	/* Directly load the keys needed for an encryption AEAD object. */
+	int (*load_encrypt_keys)(const struct krb5_enctype *krb5,
+				 const struct krb5_buffer *Ke,
+				 const struct krb5_buffer *Ki,
+				 struct krb5_buffer *setkey,
+				 gfp_t gfp);
+
+	/* Derive the key needed for a checksum hash object. */
+	int (*derive_checksum_key)(const struct krb5_enctype *krb5,
+				   const struct krb5_buffer *TK,
+				   unsigned int usage,
+				   struct krb5_buffer *setkey,
+				   gfp_t gfp);
+
+	/* Directly load the keys needed for a checksum hash object. */
+	int (*load_checksum_key)(const struct krb5_enctype *krb5,
+				 const struct krb5_buffer *Kc,
+				 struct krb5_buffer *setkey,
+				 gfp_t gfp);
+
+	/* Encrypt data in-place, inserting confounder and checksum. */
+	ssize_t (*encrypt)(const struct krb5_enctype *krb5,
+			   struct crypto_aead *aead,
+			   struct scatterlist *sg, unsigned int nr_sg,
+			   size_t sg_len,
+			   size_t data_offset, size_t data_len,
+			   bool preconfounded);
+
+	/* Decrypt data in-place, removing confounder and checksum */
+	int (*decrypt)(const struct krb5_enctype *krb5,
+		       struct crypto_aead *aead,
+		       struct scatterlist *sg, unsigned int nr_sg,
+		       size_t *_offset, size_t *_len);
+
+	/* Generate a MIC on part of a packet, inserting the checksum */
+	ssize_t (*get_mic)(const struct krb5_enctype *krb5,
+			   struct crypto_shash *shash,
+			   const struct krb5_buffer *metadata,
+			   struct scatterlist *sg, unsigned int nr_sg,
+			   size_t sg_len,
+			   size_t data_offset, size_t data_len);
+
+	/* Verify the MIC on a piece of data, removing the checksum */
+	int (*verify_mic)(const struct krb5_enctype *krb5,
+			  struct crypto_shash *shash,
+			  const struct krb5_buffer *metadata,
+			  struct scatterlist *sg, unsigned int nr_sg,
+			  size_t *_offset, size_t *_len);
+};
+
+/*
+ * Crypto size/alignment rounding convenience macros.
+ */
+#define crypto_roundup(X) ((unsigned int)round_up((X), CRYPTO_MINALIGN))
+
+#define krb5_aead_size(TFM) \
+	crypto_roundup(sizeof(struct aead_request) + crypto_aead_reqsize(TFM))
+#define krb5_aead_ivsize(TFM) \
+	crypto_roundup(crypto_aead_ivsize(TFM))
+#define krb5_shash_size(TFM) \
+	crypto_roundup(sizeof(struct shash_desc) + crypto_shash_descsize(TFM))
+#define krb5_digest_size(TFM) \
+	crypto_roundup(crypto_shash_digestsize(TFM))
+#define round16(x) (((x) + 15) & ~15)
+
+/*
+ * Self-testing data.
+ */
+struct krb5_prf_test {
+	u32 etype;
+	const char *name, *key, *octet, *prf;
+};
+
+struct krb5_key_test_one {
+	u32 use;
+	const char *key;
+};
+
+struct krb5_key_test {
+	u32 etype;
+	const char *name, *key;
+	struct krb5_key_test_one Kc, Ke, Ki;
+};
+
+struct krb5_enc_test {
+	u32 etype;
+	u32 usage;
+	const char *name, *plain, *conf, *K0, *Ke, *Ki, *ct;
+};
+
+struct krb5_mic_test {
+	u32 etype;
+	u32 usage;
+	const char *name, *plain, *K0, *Kc, *mic;
+};
+
+/*
+ * krb5_api.c
+ */
+struct crypto_aead *krb5_prepare_encryption(const struct krb5_enctype *krb5,
+					    const struct krb5_buffer *keys,
+					    gfp_t gfp);
+struct crypto_shash *krb5_prepare_checksum(const struct krb5_enctype *krb5,
+					   const struct krb5_buffer *Kc,
+					   gfp_t gfp);
+
+/*
+ * krb5_kdf.c
+ */
+int krb5_derive_Kc(const struct krb5_enctype *krb5, const struct krb5_buffer *TK,
+		   u32 usage, struct krb5_buffer *key, gfp_t gfp);
+int krb5_derive_Ke(const struct krb5_enctype *krb5, const struct krb5_buffer *TK,
+		   u32 usage, struct krb5_buffer *key, gfp_t gfp);
+int krb5_derive_Ki(const struct krb5_enctype *krb5, const struct krb5_buffer *TK,
+		   u32 usage, struct krb5_buffer *key, gfp_t gfp);
+
+/*
+ * rfc3961_simplified.c
+ */
+extern const struct krb5_crypto_profile rfc3961_simplified_profile;
+
+int crypto_shash_update_sg(struct shash_desc *desc, struct scatterlist *sg,
+			   size_t offset, size_t len);
+int authenc_derive_encrypt_keys(const struct krb5_enctype *krb5,
+				const struct krb5_buffer *TK,
+				unsigned int usage,
+				struct krb5_buffer *setkey,
+				gfp_t gfp);
+int authenc_load_encrypt_keys(const struct krb5_enctype *krb5,
+			      const struct krb5_buffer *Ke,
+			      const struct krb5_buffer *Ki,
+			      struct krb5_buffer *setkey,
+			      gfp_t gfp);
+int rfc3961_derive_checksum_key(const struct krb5_enctype *krb5,
+				const struct krb5_buffer *TK,
+				unsigned int usage,
+				struct krb5_buffer *setkey,
+				gfp_t gfp);
+int rfc3961_load_checksum_key(const struct krb5_enctype *krb5,
+			      const struct krb5_buffer *Kc,
+			      struct krb5_buffer *setkey,
+			      gfp_t gfp);
+ssize_t krb5_aead_encrypt(const struct krb5_enctype *krb5,
+			  struct crypto_aead *aead,
+			  struct scatterlist *sg, unsigned int nr_sg, size_t sg_len,
+			  size_t data_offset, size_t data_len,
+			  bool preconfounded);
+int krb5_aead_decrypt(const struct krb5_enctype *krb5,
+		      struct crypto_aead *aead,
+		      struct scatterlist *sg, unsigned int nr_sg,
+		      size_t *_offset, size_t *_len);
+ssize_t rfc3961_get_mic(const struct krb5_enctype *krb5,
+			struct crypto_shash *shash,
+			const struct krb5_buffer *metadata,
+			struct scatterlist *sg, unsigned int nr_sg, size_t sg_len,
+			size_t data_offset, size_t data_len);
+int rfc3961_verify_mic(const struct krb5_enctype *krb5,
+		       struct crypto_shash *shash,
+		       const struct krb5_buffer *metadata,
+		       struct scatterlist *sg, unsigned int nr_sg,
+		       size_t *_offset, size_t *_len);
+
+/*
+ * rfc3962_aes.c
+ */
+extern const struct krb5_enctype krb5_aes128_cts_hmac_sha1_96;
+extern const struct krb5_enctype krb5_aes256_cts_hmac_sha1_96;
+
+/*
+ * rfc6803_camellia.c
+ */
+extern const struct krb5_enctype krb5_camellia128_cts_cmac;
+extern const struct krb5_enctype krb5_camellia256_cts_cmac;
+
+/*
+ * rfc8009_aes2.c
+ */
+extern const struct krb5_enctype krb5_aes128_cts_hmac_sha256_128;
+extern const struct krb5_enctype krb5_aes256_cts_hmac_sha384_192;
+
+/*
+ * selftest.c
+ */
+#ifdef CONFIG_CRYPTO_KRB5_SELFTESTS
+int krb5_selftest(void);
+#else
+static inline int krb5_selftest(void) { return 0; }
+#endif
+
+/*
+ * selftest_data.c
+ */
+extern const struct krb5_prf_test krb5_prf_tests[];
+extern const struct krb5_key_test krb5_key_tests[];
+extern const struct krb5_enc_test krb5_enc_tests[];
+extern const struct krb5_mic_test krb5_mic_tests[];