Re: [PATCH] s390/cio: fix device lifecycle handling in css_alloc_subchannel()

[Vineeth Vijayan]

On 1/30/26 21:47, Salah Triki wrote:
> `css_alloc_subchannel()` calls `device_initialize()` before setting up
> the DMA masks. If `dma_set_coherent_mask()` or `dma_set_mask()` fails,
> the error path frees the subchannel structure directly, bypassing
> the device model reference counting.
>
> Once `device_initialize()` has been called, the embedded struct device
> must be released via `put_device()`, allowing the release callback to
> free the container structure.
>
> Fix the error path by dropping the initial device reference with
> `put_device()` instead of calling `kfree()` directly.
>
> This ensures correct device lifetime handling and avoids potential
> use-after-free or double-free issues.
>
> Fixes: e5dcf0025d7af ("s390/css: move subchannel lock allocation")
>
> Signed-off-by: Salah Triki<salah.triki@xxxxxxxxx>
> ---

Thank you.
this looks good to me.

Reviewed-by: Vineeth Vijayan <vneethv@xxxxxxxxxxxxx>