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author | Stefan Hajnoczi <stefanha@redhat.com> | 2020-09-17 10:44:55 +0100 |
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committer | Stefan Hajnoczi <stefanha@redhat.com> | 2020-09-23 13:41:58 +0100 |
commit | 8080747748f143c71076e1fd9951ca40900da574 (patch) | |
tree | b6760b3ab8cf0c495f18e335b6a88694d6983a93 /hw/virtio | |
parent | 7bd04a041addcdef6a03e6498aafaea55ca6e88b (diff) | |
download | qemu-8080747748f143c71076e1fd9951ca40900da574.zip qemu-8080747748f143c71076e1fd9951ca40900da574.tar.gz qemu-8080747748f143c71076e1fd9951ca40900da574.tar.bz2 |
virtio-crypto: don't modify elem->in/out_sg
A number of iov_discard_front/back() operations are made by
virtio-crypto. The elem->in/out_sg iovec arrays are modified by these
operations, resulting virtqueue_unmap_sg() calls on different addresses
than were originally mapped.
This is problematic because dirty memory may not be logged correctly,
MemoryRegion refcounts may be leaked, and the non-RAM bounce buffer can
be leaked.
Take a copy of the elem->in/out_sg arrays so that the originals are
preserved. The iov_discard_undo() API could be used instead (with better
performance) but requires careful auditing of the code, so do the simple
thing instead.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Li Qiang <liq3ea@gmail.com>
Message-Id: <20200917094455.822379-4-stefanha@redhat.com>
Diffstat (limited to 'hw/virtio')
-rw-r--r-- | hw/virtio/virtio-crypto.c | 17 |
1 files changed, 14 insertions, 3 deletions
diff --git a/hw/virtio/virtio-crypto.c b/hw/virtio/virtio-crypto.c index 6da12e3..54f9bbb 100644 --- a/hw/virtio/virtio-crypto.c +++ b/hw/virtio/virtio-crypto.c @@ -228,6 +228,8 @@ static void virtio_crypto_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq) size_t s; for (;;) { + g_autofree struct iovec *out_iov_copy = NULL; + elem = virtqueue_pop(vq, sizeof(VirtQueueElement)); if (!elem) { break; @@ -240,9 +242,12 @@ static void virtio_crypto_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq) } out_num = elem->out_num; - out_iov = elem->out_sg; + out_iov_copy = g_memdup(elem->out_sg, sizeof(out_iov[0]) * out_num); + out_iov = out_iov_copy; + in_num = elem->in_num; in_iov = elem->in_sg; + if (unlikely(iov_to_buf(out_iov, out_num, 0, &ctrl, sizeof(ctrl)) != sizeof(ctrl))) { virtio_error(vdev, "virtio-crypto request ctrl_hdr too short"); @@ -582,6 +587,8 @@ virtio_crypto_handle_request(VirtIOCryptoReq *request) int queue_index = virtio_crypto_vq2q(virtio_get_queue_index(request->vq)); struct virtio_crypto_op_data_req req; int ret; + g_autofree struct iovec *in_iov_copy = NULL; + g_autofree struct iovec *out_iov_copy = NULL; struct iovec *in_iov; struct iovec *out_iov; unsigned in_num; @@ -598,9 +605,13 @@ virtio_crypto_handle_request(VirtIOCryptoReq *request) } out_num = elem->out_num; - out_iov = elem->out_sg; + out_iov_copy = g_memdup(elem->out_sg, sizeof(out_iov[0]) * out_num); + out_iov = out_iov_copy; + in_num = elem->in_num; - in_iov = elem->in_sg; + in_iov_copy = g_memdup(elem->in_sg, sizeof(in_iov[0]) * in_num); + in_iov = in_iov_copy; + if (unlikely(iov_to_buf(out_iov, out_num, 0, &req, sizeof(req)) != sizeof(req))) { virtio_error(vdev, "virtio-crypto request outhdr too short"); |