Greg Kroah-Hartman
2020-Jun-16 15:34 UTC
[PATCH 5.7 094/163] crypto: virtio: Fix use-after-free in virtio_crypto_skcipher_finalize_req()
From: Longpeng(Mike) <longpeng2 at huawei.com> 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 <clabbe at baylibre.com> Cc: Gonglei <arei.gonglei at huawei.com> Cc: Herbert Xu <herbert at gondor.apana.org.au> Cc: "Michael S. Tsirkin" <mst at redhat.com> Cc: Jason Wang <jasowang at redhat.com> Cc: "David S. Miller" <davem at davemloft.net> Cc: virtualization at lists.linux-foundation.org Cc: linux-kernel at vger.kernel.org Cc: stable at vger.kernel.org Link: https://lore.kernel.org/r/20200123101000.GB24255 at Red Acked-by: Gonglei <arei.gonglei at huawei.com> Signed-off-by: Longpeng(Mike) <longpeng2 at huawei.com> Link: https://lore.kernel.org/r/20200602070501.2023-3-longpeng2 at huawei.com Signed-off-by: Michael S. Tsirkin <mst at redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org> --- drivers/crypto/virtio/virtio_crypto_algs.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/drivers/crypto/virtio/virtio_crypto_algs.c +++ b/drivers/crypto/virtio/virtio_crypto_algs.c @@ -578,10 +578,11 @@ static void virtio_crypto_skcipher_final scatterwalk_map_and_copy(req->iv, req->dst, req->cryptlen - AES_BLOCK_SIZE, AES_BLOCK_SIZE, 0); - crypto_finalize_skcipher_request(vc_sym_req->base.dataq->engine, - req, err); kzfree(vc_sym_req->iv); virtcrypto_clear_request(&vc_sym_req->base); + + crypto_finalize_skcipher_request(vc_sym_req->base.dataq->engine, + req, err); } static struct virtio_crypto_algo virtio_crypto_algs[] = { {
Apparently Analagous Threads
- Patch "crypto: virtio: Fix use-after-free in virtio_crypto_skcipher_finalize_req()" has been added to the 5.7-stable tree
- [PATCH 5.6 099/161] crypto: virtio: Fix use-after-free in virtio_crypto_skcipher_finalize_req()
- Patch "crypto: virtio: Fix use-after-free in virtio_crypto_skcipher_finalize_req()" has been added to the 5.6-stable tree
- [PATCH v2 2/2] crypto: virtio: Fix use-after-free in virtio_crypto_skcipher_finalize_req()
- [PATCH 4.14 049/190] crypto: virtio: Fix use-after-free in virtio_crypto_skcipher_finalize_req()