[PATCH 4.19 064/267] crypto: virtio: Fix use-after-free in virtio_crypto_skcipher_finalize_req()

[PATCH 4.19 064/267] crypto: virtio: Fix use-after-free in virtio_crypto_skcipher_finalize_req()

[Greg Kroah-Hartman]

From: Longpeng(Mike) <longpeng2@huawei.com>

[ Upstream commit 8c855f0720ff006d75d0a2512c7f6c4f60ff60ee ]

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 <clabbe@baylibre.com>
Cc: Gonglei <arei.gonglei@huawei.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: virtualization@lists.linux-foundation.org
Cc: linux-kernel@vger.kernel.org
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20200123101000.GB24255@Red
Acked-by: Gonglei <arei.gonglei@huawei.com>
Signed-off-by: Longpeng(Mike) <longpeng2@huawei.com>
Link: https://lore.kernel.org/r/20200602070501.2023-3-longpeng2@huawei.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/crypto/virtio/virtio_crypto_algs.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/crypto/virtio/virtio_crypto_algs.c b/drivers/crypto/virtio/virtio_crypto_algs.c
index 38432721069f..9348060cc32f 100644
--- a/drivers/crypto/virtio/virtio_crypto_algs.c
+++ b/drivers/crypto/virtio/virtio_crypto_algs.c
@@ -594,10 +594,11 @@ static void virtio_crypto_ablkcipher_finalize_req(
 		scatterwalk_map_and_copy(req->info, req->dst,
 					 req->nbytes - AES_BLOCK_SIZE,
 					 AES_BLOCK_SIZE, 0);
-	crypto_finalize_ablkcipher_request(vc_sym_req->base.dataq->engine,
-					   req, err);
 	kzfree(vc_sym_req->iv);
 	virtcrypto_clear_request(&vc_sym_req->base);
+
+	crypto_finalize_ablkcipher_request(vc_sym_req->base.dataq->engine,
+					   req, err);
 }
 
 static struct virtio_crypto_algo virtio_crypto_algs[] = { {
-- 
2.25.1

[PATCH 4.19 065/267] crypto: virtio: Fix src/dst scatterlist calculation in __virtio_crypto_skcipher_do_req()

[Greg Kroah-Hartman]

From: Longpeng(Mike) <longpeng2@huawei.com>

[ Upstream commit b02989f37fc5e865ceeee9070907e4493b3a21e2 ]

The system will crash when the users insmod crypto/tcrypt.ko with mode=38
( testing "cts(cbc(aes))" ).

Usually the next entry of one sg will be @sg@ + 1, but if this sg element
is part of a chained scatterlist, it could jump to the start of a new
scatterlist array. Fix it by sg_next() on calculation of src/dst
scatterlist.

Fixes: dbaf0624ffa5 ("crypto: add virtio-crypto driver")
Reported-by: LABBE Corentin <clabbe@baylibre.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: virtualization@lists.linux-foundation.org
Cc: linux-kernel@vger.kernel.org
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20200123101000.GB24255@Red
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Signed-off-by: Longpeng(Mike) <longpeng2@huawei.com>
Link: https://lore.kernel.org/r/20200602070501.2023-2-longpeng2@huawei.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/crypto/virtio/virtio_crypto_algs.c | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/drivers/crypto/virtio/virtio_crypto_algs.c b/drivers/crypto/virtio/virtio_crypto_algs.c
index 9348060cc32f..e9a8485c4929 100644
--- a/drivers/crypto/virtio/virtio_crypto_algs.c
+++ b/drivers/crypto/virtio/virtio_crypto_algs.c
@@ -367,13 +367,18 @@ __virtio_crypto_ablkcipher_do_req(struct virtio_crypto_sym_request *vc_sym_req,
 	int err;
 	unsigned long flags;
 	struct scatterlist outhdr, iv_sg, status_sg, **sgs;
-	int i;
 	u64 dst_len;
 	unsigned int num_out = 0, num_in = 0;
 	int sg_total;
 	uint8_t *iv;
+	struct scatterlist *sg;
 
 	src_nents = sg_nents_for_len(req->src, req->nbytes);
+	if (src_nents < 0) {
+		pr_err("Invalid number of src SG.\n");
+		return src_nents;
+	}
+
 	dst_nents = sg_nents(req->dst);
 
 	pr_debug("virtio_crypto: Number of sgs (src_nents: %d, dst_nents: %d)\n",
@@ -459,12 +464,12 @@ __virtio_crypto_ablkcipher_do_req(struct virtio_crypto_sym_request *vc_sym_req,
 	vc_sym_req->iv = iv;
 
 	/* Source data */
-	for (i = 0; i < src_nents; i++)
-		sgs[num_out++] = &req->src[i];
+	for (sg = req->src; src_nents; sg = sg_next(sg), src_nents--)
+		sgs[num_out++] = sg;
 
 	/* Destination data */
-	for (i = 0; i < dst_nents; i++)
-		sgs[num_out + num_in++] = &req->dst[i];
+	for (sg = req->dst; sg; sg = sg_next(sg))
+		sgs[num_out + num_in++] = sg;
 
 	/* Status */
 	sg_init_one(&status_sg, &vc_req->status, sizeof(vc_req->status));
-- 
2.25.1

[PATCH 4.19 066/267] crypto: virtio: Fix dest length calculation in __virtio_crypto_skcipher_do_req()

[Greg Kroah-Hartman]

From: Longpeng(Mike) <longpeng2@huawei.com>

[ Upstream commit d90ca42012db2863a9a30b564a2ace6016594bda ]

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.

Fixes: dbaf0624ffa5 ("crypto: add virtio-crypto driver")
Cc: Gonglei <arei.gonglei@huawei.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: virtualization@lists.linux-foundation.org
Cc: linux-kernel@vger.kernel.org
Cc: stable@vger.kernel.org
Signed-off-by: Longpeng(Mike) <longpeng2@huawei.com>
Link: https://lore.kernel.org/r/20200602070501.2023-4-longpeng2@huawei.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/crypto/virtio/virtio_crypto_algs.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/crypto/virtio/virtio_crypto_algs.c b/drivers/crypto/virtio/virtio_crypto_algs.c
index e9a8485c4929..ab4700e4b409 100644
--- a/drivers/crypto/virtio/virtio_crypto_algs.c
+++ b/drivers/crypto/virtio/virtio_crypto_algs.c
@@ -424,6 +424,7 @@ __virtio_crypto_ablkcipher_do_req(struct virtio_crypto_sym_request *vc_sym_req,
 		goto free;
 	}
 
+	dst_len = min_t(unsigned int, req->nbytes, dst_len);
 	pr_debug("virtio_crypto: src_len: %u, dst_len: %llu\n",
 			req->nbytes, dst_len);
 
-- 
2.25.1