[intel-lts:4.19/android_s 4156/30000] drivers/gpu/drm/virtio/virtgpu_vq.c:750 virtio_gpu_cmd_get_edids() error: 'cmd_p' dereferencing possible ERR_PTR()

[kernel test robot <lkp@intel.com>]

BCC: lkp@intel.com
CC: oe-kbuild-all@lists.linux.dev

tree:   https://github.com/intel/linux-intel-lts.git 4.19/android_s
head:   84d5fc421289417e51781e27e64fbb0fc44216ae
commit: d4f5248ba0ac929a5d79faf185766987fac4a73b [4156/30000] UPSTREAM: drm/virtio: add edid support
:::::: branch date: 3 weeks ago
:::::: commit date: 5 years ago
config: i386-randconfig-141-20240913 (https://download.01.org/0day-ci/archive/20240922/202409222012.3X1WV06O-lkp@intel.com/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Reported-by: Dan Carpenter <error27@gmail.com>
| Closes: https://lore.kernel.org/r/202409222012.3X1WV06O-lkp@intel.com/

New smatch warnings:
drivers/gpu/drm/virtio/virtgpu_vq.c:750 virtio_gpu_cmd_get_edids() error: 'cmd_p' dereferencing possible ERR_PTR()

Old smatch warnings:
drivers/gpu/drm/virtio/virtgpu_vq.c:381 virtio_gpu_cmd_create_resource() error: 'cmd_p' dereferencing possible ERR_PTR()
drivers/gpu/drm/virtio/virtgpu_vq.c:400 virtio_gpu_cmd_unref_resource() error: 'cmd_p' dereferencing possible ERR_PTR()
drivers/gpu/drm/virtio/virtgpu_vq.c:416 virtio_gpu_cmd_resource_inval_backing() error: 'cmd_p' dereferencing possible ERR_PTR()
drivers/gpu/drm/virtio/virtgpu_vq.c:433 virtio_gpu_cmd_set_scanout() error: 'cmd_p' dereferencing possible ERR_PTR()
drivers/gpu/drm/virtio/virtgpu_vq.c:455 virtio_gpu_cmd_resource_flush() error: 'cmd_p' dereferencing possible ERR_PTR()
drivers/gpu/drm/virtio/virtgpu_vq.c:484 virtio_gpu_cmd_transfer_to_host_2d() error: 'cmd_p' dereferencing possible ERR_PTR()
drivers/gpu/drm/virtio/virtgpu_vq.c:508 virtio_gpu_cmd_resource_attach_backing() error: 'cmd_p' dereferencing possible ERR_PTR()
drivers/gpu/drm/virtio/virtgpu_vq.c:646 virtio_gpu_cmd_get_display_info() error: 'cmd_p' dereferencing possible ERR_PTR()
drivers/gpu/drm/virtio/virtgpu_vq.c:668 virtio_gpu_cmd_get_capset_info() error: 'cmd_p' dereferencing possible ERR_PTR()
drivers/gpu/drm/virtio/virtgpu_vq.c:721 virtio_gpu_cmd_get_capset() error: 'cmd_p' dereferencing possible ERR_PTR()
drivers/gpu/drm/virtio/virtgpu_vq.c:767 virtio_gpu_cmd_context_create() error: 'cmd_p' dereferencing possible ERR_PTR()
drivers/gpu/drm/virtio/virtgpu_vq.c:784 virtio_gpu_cmd_context_destroy() error: 'cmd_p' dereferencing possible ERR_PTR()
drivers/gpu/drm/virtio/virtgpu_vq.c:799 virtio_gpu_cmd_context_attach_resource() error: 'cmd_p' dereferencing possible ERR_PTR()
drivers/gpu/drm/virtio/virtgpu_vq.c:816 virtio_gpu_cmd_context_detach_resource() error: 'cmd_p' dereferencing possible ERR_PTR()
drivers/gpu/drm/virtio/virtgpu_vq.c:834 virtio_gpu_cmd_resource_create_3d() error: 'cmd_p' dereferencing possible ERR_PTR()
drivers/gpu/drm/virtio/virtgpu_vq.c:861 virtio_gpu_cmd_transfer_to_host_3d() error: 'cmd_p' dereferencing possible ERR_PTR()
drivers/gpu/drm/virtio/virtgpu_vq.c:883 virtio_gpu_cmd_transfer_from_host_3d() error: 'cmd_p' dereferencing possible ERR_PTR()
drivers/gpu/drm/virtio/virtgpu_vq.c:906 virtio_gpu_cmd_submit() error: 'cmd_p' dereferencing possible ERR_PTR()
drivers/gpu/drm/virtio/virtgpu_vq.c:934 virtio_gpu_object_attach() error: we previously assumed 'obj->pages' could be null (see line 925)

vim +/cmd_p +750 drivers/gpu/drm/virtio/virtgpu_vq.c

62fb7a5e10962a Gerd Hoffmann 2014-10-28  729  
d4f5248ba0ac92 Gerd Hoffmann 2018-10-30  730  int virtio_gpu_cmd_get_edids(struct virtio_gpu_device *vgdev)
d4f5248ba0ac92 Gerd Hoffmann 2018-10-30  731  {
d4f5248ba0ac92 Gerd Hoffmann 2018-10-30  732  	struct virtio_gpu_cmd_get_edid *cmd_p;
d4f5248ba0ac92 Gerd Hoffmann 2018-10-30  733  	struct virtio_gpu_vbuffer *vbuf;
d4f5248ba0ac92 Gerd Hoffmann 2018-10-30  734  	void *resp_buf;
d4f5248ba0ac92 Gerd Hoffmann 2018-10-30  735  	int scanout;
d4f5248ba0ac92 Gerd Hoffmann 2018-10-30  736  
d4f5248ba0ac92 Gerd Hoffmann 2018-10-30  737  	if (WARN_ON(!vgdev->has_edid))
d4f5248ba0ac92 Gerd Hoffmann 2018-10-30  738  		return -EINVAL;
d4f5248ba0ac92 Gerd Hoffmann 2018-10-30  739  
d4f5248ba0ac92 Gerd Hoffmann 2018-10-30  740  	for (scanout = 0; scanout < vgdev->num_scanouts; scanout++) {
d4f5248ba0ac92 Gerd Hoffmann 2018-10-30  741  		resp_buf = kzalloc(sizeof(struct virtio_gpu_resp_edid),
d4f5248ba0ac92 Gerd Hoffmann 2018-10-30  742  				   GFP_KERNEL);
d4f5248ba0ac92 Gerd Hoffmann 2018-10-30  743  		if (!resp_buf)
d4f5248ba0ac92 Gerd Hoffmann 2018-10-30  744  			return -ENOMEM;
d4f5248ba0ac92 Gerd Hoffmann 2018-10-30  745  
d4f5248ba0ac92 Gerd Hoffmann 2018-10-30  746  		cmd_p = virtio_gpu_alloc_cmd_resp
d4f5248ba0ac92 Gerd Hoffmann 2018-10-30  747  			(vgdev, &virtio_gpu_cmd_get_edid_cb, &vbuf,
d4f5248ba0ac92 Gerd Hoffmann 2018-10-30  748  			 sizeof(*cmd_p), sizeof(struct virtio_gpu_resp_edid),
d4f5248ba0ac92 Gerd Hoffmann 2018-10-30  749  			 resp_buf);
d4f5248ba0ac92 Gerd Hoffmann 2018-10-30 @750  		cmd_p->hdr.type = cpu_to_le32(VIRTIO_GPU_CMD_GET_EDID);
d4f5248ba0ac92 Gerd Hoffmann 2018-10-30  751  		cmd_p->scanout = cpu_to_le32(scanout);
d4f5248ba0ac92 Gerd Hoffmann 2018-10-30  752  		virtio_gpu_queue_ctrl_buffer(vgdev, vbuf);
d4f5248ba0ac92 Gerd Hoffmann 2018-10-30  753  	}
d4f5248ba0ac92 Gerd Hoffmann 2018-10-30  754  
d4f5248ba0ac92 Gerd Hoffmann 2018-10-30  755  	return 0;
d4f5248ba0ac92 Gerd Hoffmann 2018-10-30  756  }
d4f5248ba0ac92 Gerd Hoffmann 2018-10-30  757  

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