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 698BBD65C43 for ; Wed, 17 Dec 2025 12:57:58 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 03F1E10E087; Wed, 17 Dec 2025 12:57:58 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="OQ6J8Hff"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.9]) by gabe.freedesktop.org (Postfix) with ESMTPS id 8F2CE10E087 for ; Wed, 17 Dec 2025 12:57:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1765976277; x=1797512277; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=edGf3gpQFeuvMvCpqdY/Xm6EAiqhq6jDx/S818uVFAE=; b=OQ6J8Hffn/+a4c90QK3M90CTHzYg9Ob2eew8WRfoo06bWXcysTOUAmMb z7W9/yp2Wq2DoqNGajEJ9oOHenjI42oSAmN8He85S5PUMIiO86KsPrDM2 D+4R6IRfrewb0Yndx/2yvwx0JKA/NLfvfMRu2+8D1nlCB6T/SF29z/82l QdDUEQNsL/VwtdopAW+kw1EX5OXU/TD5KulXEcRd7WKVZJDRhU8gb1q7S qhuYz7ErrDhPFtPtMZqrGjgjOUMrLr+qHCWXBoL6UhiOoP0wvcOVybJfQ 1dNyodo+ejqKtRlCrl5vdgqZQVTXNBf3JIHDgdRR11NlfM6f+r00O6CIs Q==; X-CSE-ConnectionGUID: 2vN/3wyHQ2ClPmZxaWVPZw== X-CSE-MsgGUID: d1yl9bkQQLSO4Mi+ZSmhlg== X-IronPort-AV: E=McAfee;i="6800,10657,11645"; a="90571080" X-IronPort-AV: E=Sophos;i="6.21,155,1763452800"; d="scan'208";a="90571080" Received: from orviesa006.jf.intel.com ([10.64.159.146]) by orvoesa101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Dec 2025 04:57:56 -0800 X-CSE-ConnectionGUID: Hh+rOCigQq6SzvE6OmGxLw== X-CSE-MsgGUID: H15dc30OQzWJUiZvBazp4A== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.21,155,1763452800"; d="scan'208";a="197401204" Received: from fpallare-mobl4.ger.corp.intel.com (HELO [10.245.245.182]) ([10.245.245.182]) by orviesa006-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Dec 2025 04:57:56 -0800 Message-ID: Date: Wed, 17 Dec 2025 12:57:52 +0000 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2] drm/xe: Fix NULL pointer dereference in xe_exec_ioctl To: =?UTF-8?Q?Tapani_P=C3=A4lli?= , intel-xe@lists.freedesktop.org Cc: matthew.brost@intel.com References: <20251217123209.430427-1-tapani.palli@intel.com> Content-Language: en-GB From: Matthew Auld In-Reply-To: <20251217123209.430427-1-tapani.palli@intel.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-BeenThere: intel-xe@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel Xe graphics driver List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-xe-bounces@lists.freedesktop.org Sender: "Intel-xe" On 17/12/2025 12:32, Tapani Pälli wrote: > Helper function xe_sync_needs_wait expects sync->fence when accessing > flags, patch makes sure we call only when sync->fence exists. > > v2: move null checking to xe_sync_needs_wait and make > xe_sync_entry_wait utilize this helper (Matthew Auld) > > Fixes NULL pointer dereference seen with Vulkan workloads: > > [ 118.410401] RIP: 0010:xe_sync_needs_wait+0x27/0x50 [xe] > > Fixes: 4ac9048d0501 ("drm/xe: Wait on in-syncs when swicthing to dma-fence mode") > Signed-off-by: Tapani Pälli > --- > drivers/gpu/drm/xe/xe_sync.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/xe/xe_sync.c b/drivers/gpu/drm/xe/xe_sync.c > index ee1344a880b9..2b6c2e2527ae 100644 > --- a/drivers/gpu/drm/xe/xe_sync.c > +++ b/drivers/gpu/drm/xe/xe_sync.c > @@ -241,7 +241,8 @@ int xe_sync_entry_wait(struct xe_sync_entry *sync) > if (sync->flags & DRM_XE_SYNC_FLAG_SIGNAL) > return 0; ^^ I think we can drop this bit, since below will now check it? > > - return dma_fence_wait(sync->fence, true); > + return xe_sync_needs_wait(sync) ? > + dma_fence_wait(sync->fence, true) : 0; > } > > /** > @@ -252,7 +253,7 @@ int xe_sync_entry_wait(struct xe_sync_entry *sync) > */ > bool xe_sync_needs_wait(struct xe_sync_entry *sync) > { > - return !(sync->flags & DRM_XE_SYNC_FLAG_SIGNAL) && > + return !(sync->flags & DRM_XE_SYNC_FLAG_SIGNAL) && sync->fence && > !test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &sync->fence->flags); Here I think we can maybe simplify: sync->fence && !test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &sync->fence->flags) Since sync->fence != NULL must imply an in-fence which will always be !signal for the flags anyway? > } >