From: Dongwon Kim <[email protected]> When a virtio-gpu resource is destroyed, any associated udmabuf must be properly torn down. Currently, the code may leave dangling references to dmabuf file descriptors in the scanout primary buffers.
This patch updates virtio_gpu_fini_udmabuf to: 1. Iterate through all active scanouts. 2. Identify dmabufs that match the resource's file descriptor. 3. Close the dmabuf and invalidate the resource's FD reference to prevent use-after-free or double-close scenarios. 4. Finally, trigger the underlying udmabuf destruction. This ensures that the display backend does not attempt to access memory or FDs that have been released by the guest or the host. Cc: Gerd Hoffmann <[email protected]> Cc: Marc-André Lureau <[email protected]> Signed-off-by: Vivek Kasireddy <[email protected]> Signed-off-by: Dongwon Kim <[email protected]> --- include/hw/virtio/virtio-gpu.h | 3 ++- hw/display/virtio-gpu-udmabuf.c | 25 ++++++++++++++++++------- hw/display/virtio-gpu.c | 2 +- 3 files changed, 21 insertions(+), 9 deletions(-) diff --git a/include/hw/virtio/virtio-gpu.h b/include/hw/virtio/virtio-gpu.h index 58e0f91fda..65312f869d 100644 --- a/include/hw/virtio/virtio-gpu.h +++ b/include/hw/virtio/virtio-gpu.h @@ -357,7 +357,8 @@ bool virtio_gpu_scanout_blob_to_fb(struct virtio_gpu_framebuffer *fb, /* virtio-gpu-udmabuf.c */ bool virtio_gpu_have_udmabuf(void); void virtio_gpu_init_udmabuf(struct virtio_gpu_simple_resource *res); -void virtio_gpu_fini_udmabuf(struct virtio_gpu_simple_resource *res); +void virtio_gpu_fini_udmabuf(VirtIOGPU *g, + struct virtio_gpu_simple_resource *res); int virtio_gpu_update_dmabuf(VirtIOGPU *g, uint32_t scanout_id, struct virtio_gpu_simple_resource *res, diff --git a/hw/display/virtio-gpu-udmabuf.c b/hw/display/virtio-gpu-udmabuf.c index d804f321aa..bd5b44f5fb 100644 --- a/hw/display/virtio-gpu-udmabuf.c +++ b/hw/display/virtio-gpu-udmabuf.c @@ -151,13 +151,6 @@ void virtio_gpu_init_udmabuf(struct virtio_gpu_simple_resource *res) res->blob = pdata; } -void virtio_gpu_fini_udmabuf(struct virtio_gpu_simple_resource *res) -{ - if (res->remapped) { - virtio_gpu_destroy_udmabuf(res); - } -} - static void virtio_gpu_free_dmabuf(VirtIOGPU *g, VGPUDMABuf *dmabuf) { struct virtio_gpu_scanout *scanout; @@ -169,6 +162,24 @@ static void virtio_gpu_free_dmabuf(VirtIOGPU *g, VGPUDMABuf *dmabuf) g_free(dmabuf); } +void virtio_gpu_fini_udmabuf(VirtIOGPU *g, struct virtio_gpu_simple_resource *res) +{ + int max_outputs = g->parent_obj.conf.max_outputs; + int i; + + for (i = 0; i < max_outputs; i++) { + VGPUDMABuf *dmabuf = g->dmabuf.primary[i]; + + if (dmabuf && (res->dmabuf_fd != -1) && + qemu_dmabuf_get_fds(dmabuf->buf, NULL)[0] == res->dmabuf_fd) { + qemu_dmabuf_close(dmabuf->buf); + res->dmabuf_fd = -1; + } + } + + virtio_gpu_destroy_udmabuf(res); +} + static VGPUDMABuf *virtio_gpu_create_dmabuf(VirtIOGPU *g, uint32_t scanout_id, diff --git a/hw/display/virtio-gpu.c b/hw/display/virtio-gpu.c index 643e91ca2a..b2af861f0d 100644 --- a/hw/display/virtio-gpu.c +++ b/hw/display/virtio-gpu.c @@ -902,7 +902,7 @@ void virtio_gpu_cleanup_mapping(VirtIOGPU *g, res->addrs = NULL; if (res->blob) { - virtio_gpu_fini_udmabuf(res); + virtio_gpu_fini_udmabuf(g, res); } } -- 2.43.0
