hw/display/virtio-gpu.c | 28 +++++++++++----------------- 1 file changed, 11 insertions(+), 17 deletions(-)
Hi Philippe,
I am really sorry for the late review; I totally missed it until now.
Please find my comments inline.
From: Marc-André Lureau <marcandre.lureau@gmail.com>
Sent: Wednesday, July 07, 2021 4:05 AM
To: Philippe Mathieu-Daudé <philmd@redhat.com>; Kasireddy, Vivek <vivek.kasireddy@intel.com>
Cc: QEMU <qemu-devel@nongnu.org>; Gerd Hoffmann <kraxel@redhat.com>; Michael S. Tsirkin <mst@redhat.com>
Subject: Re: [RFC PATCH] hw/display/virtio-gpu: Fix memory leak (CID 1453811)
Hi
On Mon, May 31, 2021 at 2:20 PM Philippe Mathieu-Daudé <philmd@redhat.com<mailto:philmd@redhat.com>> wrote:
To avoid leaking memory on the error path, reorder the
code as:
- check the parameters first
- check resource already existing
- finally allocate memory
Reported-by: Coverity (CID 1453811: RESOURCE_LEAK)
Fixes: e0933d91b1c ("virtio-gpu: Add virtio_gpu_resource_create_blob")
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com<mailto:philmd@redhat.com>>
---
RFC because the s->iov check is dubious.
Yes, that looks wrong. Before the patch, the condition is always false / dead code.
Furthermore, the init_udmabuf seems to really make sense when iov != NULL and remapping takes place.
Vivek, please review
thanks
---
hw/display/virtio-gpu.c | 28 +++++++++++-----------------
1 file changed, 11 insertions(+), 17 deletions(-)
diff --git a/hw/display/virtio-gpu.c b/hw/display/virtio-gpu.c
index 4d549377cbc..8d047007bbb 100644
--- a/hw/display/virtio-gpu.c
+++ b/hw/display/virtio-gpu.c
@@ -340,8 +340,15 @@ static void virtio_gpu_resource_create_blob(VirtIOGPU *g,
return;
}
- res = virtio_gpu_find_resource(g, cblob.resource_id);
- if (res) {
+ if (cblob.blob_mem != VIRTIO_GPU_BLOB_MEM_GUEST &&
+ cblob.blob_flags != VIRTIO_GPU_BLOB_FLAG_USE_SHAREABLE) {
+ qemu_log_mask(LOG_GUEST_ERROR, "%s: invalid memory type\n",
+ __func__);
+ cmd->error = VIRTIO_GPU_RESP_ERR_INVALID_PARAMETER;
+ return;
+ }
+
+ if (virtio_gpu_find_resource(g, cblob.resource_id)) {
qemu_log_mask(LOG_GUEST_ERROR, "%s: resource already exists %d\n",
__func__, cblob.resource_id);
cmd->error = VIRTIO_GPU_RESP_ERR_INVALID_RESOURCE_ID;
@@ -352,25 +359,12 @@ static void virtio_gpu_resource_create_blob(VirtIOGPU *g,
res->resource_id = cblob.resource_id;
res->blob_size = cblob.size;
- if (cblob.blob_mem != VIRTIO_GPU_BLOB_MEM_GUEST &&
- cblob.blob_flags != VIRTIO_GPU_BLOB_FLAG_USE_SHAREABLE) {
- qemu_log_mask(LOG_GUEST_ERROR, "%s: invalid memory type\n",
- __func__);
- cmd->error = VIRTIO_GPU_RESP_ERR_INVALID_PARAMETER;
- g_free(res);
- return;
- }
-
- if (res->iov) {
- cmd->error = VIRTIO_GPU_RESP_ERR_UNSPEC;
- return;
- }
[Kasireddy, Vivek] Yeah, removing this makes sense. Basically,
resource_create_blob = resource_create + attach_backing and I was trying to do what
attach_backing was doing but this conditional does not make sense for create_blob as
we just created the resource few lines above.
-
ret = virtio_gpu_create_mapping_iov(g, cblob.nr_entries, sizeof(cblob),
cmd, &res->addrs, &res->iov,
&res->iov_cnt);
- if (ret != 0) {
+ if (ret != 0 || res->iov) {
[Kasireddy, Vivek] Would be redundant to check for res->iov as iov == NULL case will be covered by ret != 0.
With this change,
Reviewed-by: Vivek Kasireddy <vivek.kasireddy@intel.com<mailto:vivek.kasireddy@intel.com>>
Thanks,
Vivek
cmd->error = VIRTIO_GPU_RESP_ERR_UNSPEC;
+ g_free(res);
return;
}
--
2.26.3
--
Marc-André Lureau
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