crypto: morus640 - Fix out-of-bounds access

We must load the block from the temporary variable here, not directly
from the input.

Also add forgotten zeroing-out of the uninitialized part of the
temporary block (as is done correctly in morus1280.c).

Fixes: 396be41f16fd ("crypto: morus - Add generic MORUS AEAD implementations")
Reported-by: syzbot+1fafa9c4cf42df33f716@syzkaller.appspotmail.com
Reported-by: syzbot+d82643ba80bf6937cd44@syzkaller.appspotmail.com
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 2 insertions, 1 deletions

diff --git a/crypto/morus640.c b/crypto/morus640.c
index 9fbcde307daf..5eede3749e64 100644
--- a/crypto/morus640.c
+++ b/crypto/morus640.c
@@ -274,8 +274,9 @@ static void crypto_morus640_decrypt_chunk(struct morus640_state *state, u8 *dst,
                 union morus640_block_in tail;
 
                 memcpy(tail.bytes, src, size);
+                memset(tail.bytes + size, 0, MORUS640_BLOCK_SIZE - size);
 
-                crypto_morus640_load_a(&m, src);
+                crypto_morus640_load_a(&m, tail.bytes);
                 crypto_morus640_core(state, &m);
                 crypto_morus640_store_a(tail.bytes, &m);
                 memset(tail.bytes + size, 0, MORUS640_BLOCK_SIZE - size);