From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 25EC2C77B7C for ; Fri, 5 May 2023 10:28:28 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 055EE10E5BB; Fri, 5 May 2023 10:28:27 +0000 (UTC) Received: from mga07.intel.com (mga07.intel.com [134.134.136.100]) by gabe.freedesktop.org (Postfix) with ESMTPS id 619CE10E5BB for ; Fri, 5 May 2023 10:28:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1683282504; x=1714818504; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=rl9L74pZRkN76s3QX9JPwh6SxcmjQs7F95dVJ85FAQI=; b=cV/Y4w1NM/OSMN5CSe9WhNPyZAITYJ07pg1IWvvxmwkXe7xj/TE6gIyb krytjOFyRct5dGxfj46du8Lm82Ba120+pyCTeueKULx3nAvQxZ6TgZ0z4 +2IBhmF1n6n1tCgLExOqEt0lXFCTtnFMtfeH/7SIlY120eTSQedYXtUeA LIgkxNsbHM9mNu5LQWP6JX2uNHsHNamMqGdYo7AF/sKpe5pKqQL9blAOB Xe6mGw1cyiyl7HK0conFEUIbshNrLKahSUfZ3f0XE8pb2feCuMzb17BPR haKkk9/So3b8KlzeA/ugxBpYovNhqwBNXtzvT1mRraG05L8B+e47kzFfx g==; X-IronPort-AV: E=McAfee;i="6600,9927,10700"; a="414713723" X-IronPort-AV: E=Sophos;i="5.99,251,1677571200"; d="scan'208";a="414713723" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 May 2023 03:28:22 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10700"; a="762396246" X-IronPort-AV: E=Sophos;i="5.99,251,1677571200"; d="scan'208";a="762396246" Received: from unknown (HELO intel.com) ([10.237.72.65]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 May 2023 03:28:21 -0700 Date: Fri, 5 May 2023 13:28:15 +0300 From: "Lisovskiy, Stanislav" To: Andrzej Hajda Message-ID: References: <20230505082212.27089-1-stanislav.lisovskiy@intel.com> <701bcdab-0070-1b3e-580b-b7bcd7c1e315@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <701bcdab-0070-1b3e-580b-b7bcd7c1e315@intel.com> Subject: Re: [Intel-gfx] [PATCH] drm/i915: Fix NULL ptr deref by checking new_crtc_state X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: intel-gfx@lists.freedesktop.org Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On Fri, May 05, 2023 at 11:29:22AM +0200, Andrzej Hajda wrote: > On 05.05.2023 10:22, Stanislav Lisovskiy wrote: > > intel_atomic_get_new_crtc_state can return NULL, unless crtc state wasn't > > obtained previously with intel_atomic_get_crtc_state, so we must check it > > for NULLness here, just as in many other places, where we can't guarantee > > that intel_atomic_get_crtc_state was called. > > We are currently getting NULL ptr deref because of that, so this fix was > > confirmed to help. > > > > Fixes: 74a75dc90869 ("drm/i915/display: move plane prepare/cleanup to intel_atomic_plane.c") > > Signed-off-by: Stanislav Lisovskiy > > I wonder if it wouldn't be safer to move the check to > intel_crtc_needs_modeset, up to you. > > Reviewed-by: Andrzej Hajda Hi Andrzej, Thank you for the review, I would probably still prefer to leave that check to the calling site, because depending on new_crtc_state availability calling site might need to do different actions, so it anyway has to be dealt with. Stan > > Regards > Andrzej > > > --- > > drivers/gpu/drm/i915/display/intel_atomic_plane.c | 4 ++-- > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/gpu/drm/i915/display/intel_atomic_plane.c b/drivers/gpu/drm/i915/display/intel_atomic_plane.c > > index 9f670dcfe76e..4125ee07a271 100644 > > --- a/drivers/gpu/drm/i915/display/intel_atomic_plane.c > > +++ b/drivers/gpu/drm/i915/display/intel_atomic_plane.c > > @@ -1029,7 +1029,7 @@ intel_prepare_plane_fb(struct drm_plane *_plane, > > int ret; > > if (old_obj) { > > - const struct intel_crtc_state *crtc_state = > > + const struct intel_crtc_state *new_crtc_state = > > intel_atomic_get_new_crtc_state(state, > > to_intel_crtc(old_plane_state->hw.crtc)); > > @@ -1044,7 +1044,7 @@ intel_prepare_plane_fb(struct drm_plane *_plane, > > * This should only fail upon a hung GPU, in which case we > > * can safely continue. > > */ > > - if (intel_crtc_needs_modeset(crtc_state)) { > > + if (new_crtc_state && intel_crtc_needs_modeset(new_crtc_state)) { > > ret = i915_sw_fence_await_reservation(&state->commit_ready, > > old_obj->base.resv, > > false, 0, >