Re: [PATCH 3/6] soc: qcom: pmic_glink_altmode: fix drm bridge use-after-free

2024-02-22 Thread Dmitry Baryshkov
On Sat, 17 Feb 2024 at 17:03, Johan Hovold wrote: > > A recent DRM series purporting to simplify support for "transparent > bridges" and handling of probe deferrals ironically exposed a > use-after-free issue on pmic_glink_altmode probe deferral. > > This has manifested itself as the display

Re: [PATCH 3/6] soc: qcom: pmic_glink_altmode: fix drm bridge use-after-free

2024-02-21 Thread Bjorn Andersson
On Sat, Feb 17, 2024 at 04:02:25PM +0100, Johan Hovold wrote: > A recent DRM series purporting to simplify support for "transparent > bridges" and handling of probe deferrals ironically exposed a > use-after-free issue on pmic_glink_altmode probe deferral. > > This has manifested itself as the

Re: [3/6] soc: qcom: pmic_glink_altmode: fix drm bridge use-after-free

2024-02-20 Thread Markus Elfring
>> The function call “fwnode_handle_put(fwnode)” is used in multiple if >> branches. >> https://elixir.bootlin.com/linux/v6.8-rc5/source/drivers/soc/qcom/pmic_glink_altmode.c#L435 >> >> I suggest to add a jump target so that a bit of exception handling >> can be better reused at the end of this

Re: [PATCH 3/6] soc: qcom: pmic_glink_altmode: fix drm bridge use-after-free

2024-02-20 Thread Johan Hovold
On Tue, Feb 20, 2024 at 11:55:57AM +0100, Markus Elfring wrote: > … > > Specifically, the dp-hpd bridge is currently registered before all > > resources have been acquired which means that it can also be > > deregistered on probe deferrals. > > > > In the meantime there is a race window where the

Re: [PATCH 3/6] soc: qcom: pmic_glink_altmode: fix drm bridge use-after-free

2024-02-20 Thread Markus Elfring
… > Specifically, the dp-hpd bridge is currently registered before all > resources have been acquired which means that it can also be > deregistered on probe deferrals. > > In the meantime there is a race window where the new aux bridge driver > (or PHY driver previously) may have looked up the

Re: [PATCH 3/6] soc: qcom: pmic_glink_altmode: fix drm bridge use-after-free

2024-02-20 Thread Markus Elfring
… > Specifically, the dp-hpd bridge is currently registered before all > resources have been acquired which means that it can also be > deregistered on probe deferrals. > > In the meantime there is a race window where the new aux bridge driver > (or PHY driver previously) may have looked up the

[PATCH 3/6] soc: qcom: pmic_glink_altmode: fix drm bridge use-after-free

2024-02-17 Thread Johan Hovold
A recent DRM series purporting to simplify support for "transparent bridges" and handling of probe deferrals ironically exposed a use-after-free issue on pmic_glink_altmode probe deferral. This has manifested itself as the display subsystem occasionally failing to initialise and NULL-pointer