> -----Original Message----- > From: Sachin Kamat [mailto:sachin.kamat@xxxxxxxxxx] > Sent: Thursday, November 22, 2012 5:19 PM > To: Inki Dae > Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx; jy0922.shim@xxxxxxxxxxx; > patches@xxxxxxxxxx > Subject: Re: [PATCH 1/1] drm/exynos: Fix potential NULL pointer > dereference in exynos_drm_encoder.c > > [snip] > >> >> And NULL pointer checking was already done above like below, > >> >> if (overlay_ops && overlay_ops->disable) > >> >> overlay_ops->disable(manager->dev, zpos); > >> > Correct. But that check is applicable only for that one statement > >> > (overlay_ops->disable(manager->dev, zpos);). > >> > > >> > Similar check needs to be added to below 'if' code too. > >> > >> What are your comments about this? > >> > > > > Left condition first is checked so as I mentioned before, it doesn't > need > > overlay_ops checking because that was checked already. why do you think > > overlay_ops should be checked again? > > > > Consider the case when overlay_ops is NULL. > > if (overlay_ops && overlay_ops->disable) > overlay_ops->disable(manager->dev, zpos); > > It does not enter this condition as overlay_ops is NULL and moves to > the next statement, > if (overlay_ops->wait_for_vblank) where it gets dereferenced. > > Please note we are not returning back from the first condition if > overlay_ops is NULL. > Hence we need to check the condition in second case too. > Ah~ Right. I didn't check it surely. :) Thanks, Inki Dae > -- > With warm regards, > Sachin _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
