Patch "crypto: virtio: Fix dest length calculation in __virtio_crypto_skcipher_do_req()" has been added to the 5.6-stable tree

This is a note to let you know that I've just added the patch titled

crypto: virtio: Fix dest length calculation in __virtio_crypto_skcipher_do_req()

to the 5.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
crypto-virtio-fix-dest-length-calculation-in-__virtio_crypto_skcipher_do_req.patch
and it can be found in the queue-5.6 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From d90ca42012db2863a9a30b564a2ace6016594bda Mon Sep 17 00:00:00 2001
From: "Longpeng(Mike)" <[email protected]>
Date: Tue, 2 Jun 2020 15:05:01 +0800
Subject: crypto: virtio: Fix dest length calculation in __virtio_crypto_skcipher_do_req()

From: Longpeng(Mike) <[email protected]>

commit d90ca42012db2863a9a30b564a2ace6016594bda upstream.

The src/dst length is not aligned with AES_BLOCK_SIZE(which is 16) in some testcases in tcrypto.ko.

For example, the src/dst length of one of cts(cbc(aes))'s testcase is 17, the crypto_virtio driver will set @src_data_len=16 but @dst_data_len=17 in this case and get a wrong at then end.

SRC: pp pp pp pp pp pp pp pp pp pp pp pp pp pp pp pp pp (17 bytes)
EXP: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc pp (17 bytes)
DST: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 00 (pollute the last bytes) (pp: plaintext cc:ciphertext)

Fix this issue by limit the length of dest buffer.

---
 drivers/crypto/virtio/virtio_crypto_algs.c |    1 +
 1 file changed, 1 insertion(+)

@@ -402,6 +402,7 @@ __virtio_crypto_skcipher_do_req(struct v
 		goto free;
 	}
 
+	dst_len = min_t(unsigned int, req->cryptlen, dst_len);
 	pr_debug("virtio_crypto: src_len: %u, dst_len: %llu\n",
 			req->cryptlen, dst_len);
 

Patches currently in stable-queue which might be from [email protected] are

queue-5.6/crypto-virtio-fix-src-dst-scatterlist-calculation-in-__virtio_crypto_skcipher_do_req.patch queue-5.6/crypto-virtio-fix-dest-length-calculation-in-__virtio_crypto_skcipher_do_req.patch queue-5.6/crypto-virtio-fix-use-after-free-in-virtio_crypto_skcipher_finalize_req.patch