From: Xiaomeng Tong <xiam0nd.tong@gmail.com> stable inclusion from stable-v5.10.137 commit 259773fc874258606c0121767a4a27466ff337eb category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I60PLB Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ Upstream commit bd63f11f4c3c46afec07d821f74736161ff6e526 ] 'cache_ent' could be set NULL inside virtio_gpu_cmd_get_capset() and it will lead to a NULL dereference by a lately use of it (i.e., ptr = cache_ent->caps_cache). Fix it with a NULL check. Fixes: 62fb7a5e10962 ("virtio-gpu: add 3d/virgl support") Signed-off-by: Xiaomeng Tong <xiam0nd.tong@gmail.com> Reviewed-by: Chia-I Wu <olvaffe@gmail.com> Link: http://patchwork.freedesktop.org/patch/msgid/20220327050945.1614-1-xiam0nd.t... [ kraxel: minor codestyle fixup ] Signed-off-by: Gerd Hoffmann <kraxel@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> Reviewed-by: Wei Li <liwei391@huawei.com> --- drivers/gpu/drm/virtio/virtgpu_ioctl.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/virtio/virtgpu_ioctl.c b/drivers/gpu/drm/virtio/virtgpu_ioctl.c index c8da7adc6b30..33b8ebab178a 100644 --- a/drivers/gpu/drm/virtio/virtgpu_ioctl.c +++ b/drivers/gpu/drm/virtio/virtgpu_ioctl.c @@ -470,8 +470,10 @@ static int virtio_gpu_get_caps_ioctl(struct drm_device *dev, spin_unlock(&vgdev->display_info_lock); /* not in cache - need to talk to hw */ - virtio_gpu_cmd_get_capset(vgdev, found_valid, args->cap_set_ver, - &cache_ent); + ret = virtio_gpu_cmd_get_capset(vgdev, found_valid, args->cap_set_ver, + &cache_ent); + if (ret) + return ret; virtio_gpu_notify(vgdev); copy_exit: -- 2.20.1