From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from fanzine2.igalia.com (fanzine2.igalia.com [213.97.179.56]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 30CDC48A8A6 for ; Fri, 11 Sep 2026 13:59:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=213.97.179.56 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789135151; cv=none; b=GkV7p3O+hbgNha7y/FsqpXBPV8f4NTuB7eRKoQ2r8YoD7u/2J36nGRUwUnqWtHsu73xUTXUdPDnfH6iW/cSFP0Kgz+fhkNPG1N7MPn3Z13uJH62oUoMGVIkKZEWZq/8IMuf1qIEH9Qd3t+E4WUFQrcsRmNqiWaQ/hKBKoernNCY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789135151; c=relaxed/simple; bh=qyZRqlRVa+te18rp4tHtL2Z96Joq707rpJxoDVai6bE=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=RtNmfu0Eyfx0vxgU1dhcelxuJx0BN1PGIZXUMQSy5lVLKa95PCgWmqG4gYZuWRiveqUfTfhnMePpN2q6G++DE0oJec5YpOnbXfla5UunZrESi0rKnqYQ/EgaMJzJi0ejJDIWf/hXSDzsHMuw8OuPKMl51JY2fk6g6PCoOJf78QU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=igalia.com; spf=pass smtp.mailfrom=igalia.com; dkim=pass (2048-bit key) header.d=igalia.com header.i=@igalia.com header.b=TfDfx0Ki; arc=none smtp.client-ip=213.97.179.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=igalia.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=igalia.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=igalia.com header.i=@igalia.com header.b="TfDfx0Ki" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=igalia.com; s=20170329; h=Content-Transfer-Encoding:Content-Type:From:Cc:To:Subject: MIME-Version:Date:Message-ID:From:Reply-To; bh=NUjN4B4f7lGZ0KhNS6XMFk8J0whNkOXMOPXQ3kaf6lc=; b=TfDfx0KimNdWpbzcT+1nHoreWq k2ETKfEy4meSWlDd9bnTuSRZxGViWyaTTh2bgtAIjk7pHynVaZjo3PZVwYKGz8rtteKmPkpx4KdeB 8TV7drQ0eo79j5FAVnz//7Z4lSM76YWHVJwcFpm0/aXuy+SBOuHAoFskdfwPBzdZ2+oNIa8Yv7pm0 hSVp+0HPnT2Db4+an24NFZjt1mKaT00Q0vgWOuEM+Wf58w6gm+j360WSPCceabNu2IhhX662wU6SL PuhzuZpiyRkr+AEgU6Zh1WUy7wpBtqN8UqC7EPJEGe3VwJYJuI2YCfXgvQ0YmTZ+l/5airPDkW7IR jETV7bxw==; Received: from 113.red-79-144-92.dynamicip.rima-tde.net ([79.144.92.113] helo=[192.168.1.210]) by fanzine2.igalia.com with esmtpsa (Cipher TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_128_GCM:128) (Exim) id 1x51m2-000hUv-IU; Fri, 11 Sep 2026 15:58:38 +0200 Message-ID: <48a67b88-7ad8-4764-bab0-c226e9247dda@igalia.com> Date: Fri, 11 Sep 2026 15:58:36 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v4] drm: Fix drm_pending_vblank_event leak in error path for out_fence_ptr To: Thadeu Lima de Souza Cascardo , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter Cc: dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, kernel-dev@igalia.com, sashiko-bot@kernel.org References: <20260826-drm_pending_vblank_event_leak-v4-1-f8de8b996b9d@igalia.com> Content-Language: en-US From: Melissa Wen In-Reply-To: <20260826-drm_pending_vblank_event_leak-v4-1-f8de8b996b9d@igalia.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 26/08/2026 13:46, Thadeu Lima de Souza Cascardo wrote: > When an out_fence_ptr is provided but DRM_MODE_PAGE_FLIP_EVENT is not > set, a drm_pending_vblank_event will be allocated. If later, there is an > allocation failure or another failure at setup_out_fence(), that event > will not have base.fence set and it will not be released at > complete_signaling(). > > Release the event and set crtc_state->event to NULL just like in the > DRM_MODE_PAGE_FLIP_EVENT case when there is a failure at > drm_event_reserve_init(). That is, prepare_signaling() releases the > event and there is nothing to be done at complete_signaling(). Use > drm_event_cancel_free() as that will also undo drm_event_reserve_init() > in case it has been called. LGTM. Thanks! Reviewed-by: Melissa Wen > > Reported-by: sashiko-bot@kernel.org > Closes: https://sashiko.dev/#/patchset/20260727-drm_crtc_atomic_commit_leak-v1-1-23d9948a9d7c@igalia.com?part=1 > Fixes: 92c715fca907 ("drm/atomic: Fix double free in drm_atomic_state_default_clear") > Signed-off-by: Thadeu Lima de Souza Cascardo > --- > Changes in v4: > - Rename label to err_free_event. > - Use crtc_state->event instead of a local variable e. > - Link to v3: https://patch.msgid.link/20260817-drm_pending_vblank_event_leak-v3-1-7582b24447d0@igalia.com > > Changes in v3: > - Use a label for the common exit pattern. > - Link to v2: https://patch.msgid.link/20260729-drm_pending_vblank_event_leak-v2-1-a5074aae07df@igalia.com > > Changes in v2: > - Fix UAF when DRM_MODE_PAGE_FLIP_EVENT is used. > - Link to v1: https://patch.msgid.link/20260728-drm_pending_vblank_event_leak-v1-1-08429b920b16@igalia.com > --- > drivers/gpu/drm/drm_atomic_uapi.c | 13 ++++++++++--- > 1 file changed, 10 insertions(+), 3 deletions(-) > > diff --git a/drivers/gpu/drm/drm_atomic_uapi.c b/drivers/gpu/drm/drm_atomic_uapi.c > index ae7667d1072d..8c0eea2fed4a 100644 > --- a/drivers/gpu/drm/drm_atomic_uapi.c > +++ b/drivers/gpu/drm/drm_atomic_uapi.c > @@ -1458,10 +1458,12 @@ static int prepare_signaling(struct drm_device *dev, > struct dma_fence *fence; > struct drm_out_fence_state *f; > > + ret = -ENOMEM; > + > f = krealloc(*fence_state, sizeof(**fence_state) * > (*num_fences + 1), GFP_KERNEL); > if (!f) > - return -ENOMEM; > + goto err_free_event; > > memset(&f[*num_fences], 0, sizeof(*f)); > > @@ -1470,12 +1472,12 @@ static int prepare_signaling(struct drm_device *dev, > > fence = drm_crtc_create_fence(crtc); > if (!fence) > - return -ENOMEM; > + goto err_free_event; > > ret = setup_out_fence(&f[(*num_fences)++], fence); > if (ret) { > dma_fence_put(fence); > - return ret; > + goto err_free_event; > } > > crtc_state->event->base.fence = fence; > @@ -1531,6 +1533,11 @@ static int prepare_signaling(struct drm_device *dev, > } > > return 0; > + > +err_free_event: > + drm_event_cancel_free(dev, &crtc_state->event->base); > + crtc_state->event = NULL; > + return ret; > } > > static void complete_signaling(struct drm_device *dev, > > --- > base-commit: 4d4be202165e832d74849b4a68e289a2a377039c > change-id: 20260728-drm_pending_vblank_event_leak-a36cedb296ba > > Best regards, > -- > Thadeu Lima de Souza Cascardo >