On Fri, Apr 05, 2024 at 11:39:33PM +0300, Dmitry Baryshkov wrote: > On Fri, 5 Apr 2024 at 22:17, Ville Syrjälä > <ville.syrjala@xxxxxxxxxxxxxxx> wrote: > > > > On Fri, Apr 05, 2024 at 06:24:01AM +0300, Dmitry Baryshkov wrote: > > > On Thu, Apr 04, 2024 at 11:33:25PM +0300, Ville Syrjala wrote: > > > > From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > > > > > > > > The modes[] array contains pointers to modes on the connectors' > > > > mode lists, which are protected by dev->mode_config.mutex. > > > > Thus we need to extend modes[] the same protection or by the > > > > time we use it the elements may already be pointing to > > > > freed/reused memory. > > > > > > > > Cc: stable@xxxxxxxxxxxxxxx > > > > Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/10583 > > > > Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > > > > > > Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx> > > > > > > I tried looking for the proper Fixes tag, but it looks like it might be > > > something like 386516744ba4 ("drm/fb: fix fbdev object model + cleanup properly.") > > > > The history is rather messy. I think it was originally completely > > lockless and broken, and got fixed piecemeal later in these: > > commit 7394371d8569 ("drm: Take lock around probes for drm_fb_helper_hotplug_event") > > commit 966a6a13c666 ("drm: Hold mode_config.lock to prevent hotplug whilst setting up crtcs") > > > > commit e13a05831050 ("drm/fb-helper: Stop using mode_config.mutex for internals") > > looks to me like where the race might have been re-introduced. > > But didn't do a thorough analysis so not 100% sure. It's all > > rather ancient history by now so a Fixes tag doesn't seem all > > that useful anyway. > > Well, you have added stable to cc list, so you expect to have this > patch backported. Then it should either have a kernel version as a > 'starting' point or a Fixes tag to assist the sable team. It'll get backported just fine without either. -- Ville Syrjälä Intel
