blob: 9532f1c960a1f84a1fd48062d10affc03e2a6714 [file] [log] [blame]
From d5dc975dc65a44a1fa8c1e8ce7c7adcdbf8c73ba Mon Sep 17 00:00:00 2001
From: "Longpeng(Mike)" <>
Date: Tue, 2 Jun 2020 15:05:00 +0800
Subject: [PATCH] crypto: virtio: Fix use-after-free in
commit 8c855f0720ff006d75d0a2512c7f6c4f60ff60ee upstream.
The system'll crash when the users insmod crypto/tcrypto.ko with mode=155
( testing "authenc(hmac(sha1),cbc(aes))" ). It's caused by reuse the memory
of request structure.
In crypto_authenc_init_tfm(), the reqsize is set to:
[PART 1] sizeof(authenc_request_ctx) +
[PART 2] ictx->reqoff +
[PART 3] MAX(ahash part, skcipher part)
and the 'PART 3' is used by both ahash and skcipher in turn.
When the virtio_crypto driver finish skcipher req, it'll call ->complete
callback(in crypto_finalize_skcipher_request) and then free its
resources whose pointers are recorded in 'skcipher parts'.
However, the ->complete is 'crypto_authenc_encrypt_done' in this case,
it will use the 'ahash part' of the request and change its content,
so virtio_crypto driver will get the wrong pointer after ->complete
finish and mistakenly free some other's memory. So the system will crash
when these memory will be used again.
The resources which need to be cleaned up are not used any more. But the
pointers of these resources may be changed in the function
"crypto_finalize_skcipher_request". Thus release specific resources before
calling this function.
Fixes: dbaf0624ffa5 ("crypto: add virtio-crypto driver")
Reported-by: LABBE Corentin <>
Cc: Gonglei <>
Cc: Herbert Xu <>
Cc: "Michael S. Tsirkin" <>
Cc: Jason Wang <>
Cc: "David S. Miller" <>
Acked-by: Gonglei <>
Signed-off-by: Longpeng(Mike) <>
Signed-off-by: Michael S. Tsirkin <>
Signed-off-by: Paul Gortmaker <>
diff --git a/drivers/crypto/virtio/virtio_crypto_algs.c b/drivers/crypto/virtio/virtio_crypto_algs.c
index a489809a339e..6ca9535c34a3 100644
--- a/drivers/crypto/virtio/virtio_crypto_algs.c
+++ b/drivers/crypto/virtio/virtio_crypto_algs.c
@@ -582,10 +582,11 @@ static void virtio_crypto_ablkcipher_finalize_req(
scatterwalk_map_and_copy(req->info, req->dst,
req->nbytes - AES_BLOCK_SIZE,
- crypto_finalize_ablkcipher_request(vc_sym_req->base.dataq->engine,
- req, err);
+ crypto_finalize_ablkcipher_request(vc_sym_req->base.dataq->engine,
+ req, err);
static struct virtio_crypto_algo virtio_crypto_algs[] = { {