Re: [PATCH v3] drm/virtio: share one vbuf cache across all devices

[sashiko-bot@kernel.org]

> virtio_gpu_alloc_vbufs() creates a kmem_cache with the fixed name
> "virtio-gpu-vbufs" for every virtio-gpu device and destroys it from
> virtio_gpu_release(), which only runs once the last drm_device
> reference is dropped.
> 
> Two live virtio-gpu devices are enough to hit this: the second
> kmem_cache_create() call finds the name already taken and
> kmem_cache_sanity_check() WARNs. This reproduces at plain boot with
> two "-device virtio-gpu-pci" on the QEMU command line, no sysfs
> remove/rescan or held-open fd needed.
> 
>   kmem_cache of name 'virtio-gpu-vbufs' already exists
>   WARNING: mm/slab_common.c:111 at __kmem_cache_create_args
>   Call Trace:
>    virtio_gpu_alloc_vbufs
> [ ... ]
> at module init and destroy it at module exit instead of per device.
> 
> Reported-by: syzbot+1b129b44597a126d2d79@syzkaller.appspotmail.com
> Closes: https://syzkaller.appspot.com/bug?extid=1b129b44597a126d2d79
> Signed-off-by: Nguyen Ngoc Thang <ngocthang2710.1999@gmail.com>

Sashiko has reviewed this patch and found no issues. It looks great!

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Sashiko AI review · https://sashiko.dev/#/patchset/20261010150429.17036-1-ngocthang2710.1999@gmail.com?part=1