From: Gonglei Date: Thu, 22 Dec 2016 03:01:28 +0000 (+0800) Subject: virtio-crypto: zeroize the key material before free X-Git-Tag: qemu-xen-4.10.0-rc1~579^2~21 X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=02ed3e7c1665205ddae052774d6f26c71d3d9b30;p=qemu-xen.git virtio-crypto: zeroize the key material before free Common practice with sensitive information (key material, passwords, etc). Prevents sensitive information from being exposed by accident later in coredumps, memory disclosure bugs when heap memory is reused, etc. Sensitive information is sometimes also held in mlocked pages to prevent it being swapped to disk but that's not being done here. Let's zeroize the memory of CryptoDevBackendSymOpInfo structure pointed for key material security. [Thanks to Stefan for help with crafting the commit message] Signed-off-by: Gonglei Reviewed-by: Stefan Hajnoczi Reviewed-by: Eric Blake Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- diff --git a/hw/virtio/virtio-crypto.c b/hw/virtio/virtio-crypto.c index fc30bc3ddc..296472fc6e 100644 --- a/hw/virtio/virtio-crypto.c +++ b/hw/virtio/virtio-crypto.c @@ -337,7 +337,18 @@ static void virtio_crypto_free_request(VirtIOCryptoReq *req) { if (req) { if (req->flags == CRYPTODEV_BACKEND_ALG_SYM) { - g_free(req->u.sym_op_info); + size_t max_len; + CryptoDevBackendSymOpInfo *op_info = req->u.sym_op_info; + + max_len = op_info->iv_len + + op_info->aad_len + + op_info->src_len + + op_info->dst_len + + op_info->digest_result_len; + + /* Zeroize and free request data structure */ + memset(op_info, 0, sizeof(*op_info) + max_len); + g_free(op_info); } g_free(req); }