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>

diff --git a/crypto/morus640.c b/crypto/morus640.c
index 9fbcde3..5eede37 100644 (file)
--- 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);