Re: [PATCH] parisc: led: fix reference leak on failed device registration

[Helge Deller]

Hi Jiri,

On 4/23/26 07:24, Jiri Slaby wrote:
> On 17. 04. 26, 11:39, Helge Deller wrote:
> > On 4/15/26 19:05, Guangshuo Li wrote:
> > > When platform_device_register() fails in startup_leds(), the embedded
> > > struct device in platform_leds has already been initialized by
> > > device_initialize(), but the failure path only reports the error and
> > > does not drop the device reference for the current platform device:
> > >
> > >    startup_leds()
> > >      -> platform_device_register(&platform_leds)
> > >         -> device_initialize(&platform_leds.dev)
> > >         -> setup_pdev_dma_masks(&platform_leds)
> > >         -> platform_device_add(&platform_leds)
> > >
> > > This leads to a reference leak when platform_device_register() fails.
> > > Fix this by calling platform_device_put() after reporting the error.
> > >
> > > The issue was identified by a static analysis tool I developed and
> > > confirmed by manual review.
> > >
> > > Fixes: 789e527adfc33 ("parisc: led: Rewrite LED/LCD driver to utilizize Linux LED subsystem")
> > > Cc: stable@xxxxxxxxxxxxxxx
> > > Signed-off-by: Guangshuo Li <lgs201920130244@xxxxxxxxx>
> > > ---
> > >   drivers/parisc/led.c | 6 ++++--
> > >   1 file changed, 4 insertions(+), 2 deletions(-)
> >
> > applied.
> > Thanks!
> > Helge
>
> Unless the static pcmtst_pdev has ->type->release or ->release set, the patch triggers a warning upon put().
>
> platform_device_register() should be fixed instead.

Thanks for the notice! I'm going to revert that patch.

Just yesterday I refused to apply the other patches for fbdev and suggested
to fix platform_device_register() instead. See:
https://marc.info/?l=linux-fbdev&m=177687117206684&w=2

> See also:
> https://patchew.org/linux/20260415174159.3625777-1-lgs201920130244@xxxxxxxxx/
Thanks!
Helge