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, 23 insertions, 0 deletions

diff --git a/net/mac80211/aead_api.h b/net/mac80211/aead_api.h
new file mode 100644
index 000000000..7d463b809
--- /dev/null
+++ b/net/mac80211/aead_api.h
@@ -0,0 +1,23 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef _AEAD_API_H
+#define _AEAD_API_H
+
+#include <crypto/aead.h>
+#include <linux/crypto.h>
+
+struct crypto_aead *
+aead_key_setup_encrypt(const char *alg, const u8 key[],
+		       size_t key_len, size_t mic_len);
+
+int aead_encrypt(struct crypto_aead *tfm, u8 *b_0, u8 *aad,
+		 size_t aad_len, u8 *data,
+		 size_t data_len, u8 *mic);
+
+int aead_decrypt(struct crypto_aead *tfm, u8 *b_0, u8 *aad,
+		 size_t aad_len, u8 *data,
+		 size_t data_len, u8 *mic);
+
+void aead_key_free(struct crypto_aead *tfm);
+
+#endif /* _AEAD_API_H */