From nobody Mon Sep 28 05:00:53 2026 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 81CCA3BFE38 for ; Wed, 26 Aug 2026 11:47:15 +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=1787744840; cv=none; b=uqOyKZDBspqWjAbDcbDYq/peGGpQbi6JahmEm2M+639wfK4/GvOjY3nM+siebF0Tti7q+l6BlE3KstDdWpiPLZq8U2I0dsdGnMxbmML1pvD12bIF6aCy4y6gnF0hoCwxKKzWbjUBb8d9ywHekVP5i5DTaHM80SrQNN04Sln8q+g= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787744840; c=relaxed/simple; bh=Kl2zqF1k9v02JQ2bkbqHZklZjGBY3oXZmTa6rpngl9Q=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:To:Cc; b=Vn+zco3StQ0DxwJLQnI7ejt4VDf0WMINekXvZVhQNVvp1kYyCwZCYXyTDhdEu8ZNStOJ+Uyc7DfmVT0+7VQRfkzNbJ6330tyxNgSzzsQu3SlraW11t/Mhfpfh7tG5qDdG7qe2Oqu6xLXakNt8BnUqvEWxBH0NwKC4sAxagFbMYo= 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=nkeYywBj; 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="nkeYywBj" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=igalia.com; s=20170329; h=Cc:To:Message-Id:Content-Transfer-Encoding:Content-Type: MIME-Version:Subject:Date:From:From:Reply-To; bh=mDBT0y4CQaDDC0iV3ivBJAKjXjAA2GuZiocMc8fGFFs=; b=nkeYywBjnLAG9XQvSrzvj/vM81 AC0D3khBYW52boaKC6MbgWS6UGYVPRWDTNvmBsj+ZCaLnbGFKNIegs9H/+S0439XkznEFDT5m4Mm/ nbcqsdxKur6T737/V6SggLaZJx56VrpLnGR9+/0w6ipP9NX8U/+ofWd/Kb31WGq19tB1+3CG+PIOr KrNP09qeri4Ue2XbdoFCpIURx0oB24kS5zRqP9ZOvWZ+7Iu+3a0aFqIyGHSHMpxa7pWnIL8polS4s 6rRbGxrDRYNBIJpyphEv0RJB1nnOROiiFhghAjNtogp9UM4GDAfkKMGUynR99/z7FPjRZa4HlKuZx 9jt67Fxw==; Received: from 179-125-75-211-dinamico.pombonet.net.br ([179.125.75.211] helo=[127.0.0.1]) by fanzine2.igalia.com with esmtpsa (Cipher TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim) id 1wzC5y-009WKN-VD; Wed, 26 Aug 2026 13:47:07 +0200 From: Thadeu Lima de Souza Cascardo Date: Wed, 26 Aug 2026 08:46:58 -0300 Subject: [PATCH v4] drm: Fix drm_pending_vblank_event leak in error path for out_fence_ptr Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20260826-drm_pending_vblank_event_leak-v4-1-f8de8b996b9d@igalia.com> X-B4-Tracking: v=1; b=H4sIADHSjmoC/43OwU7DMBAE0F+pfMbI3rhx0hP/gapoHW/TpalT2 akFqvLvOOUAiEM5jjR6MzeRKDIlsdvcRKTMiadQgnnaiP6IYSDJvmQBCmploZE+nrsLBc9h6LI bMZw6yhTmbiQ8SazqnryDtnYoinGJdOD3u/+6/8rp6t6on1d0bRw5zVP8uB/Ieu39dytrqaVqD LSuBeV0/cIDjozP/XQW61iGn1z7iIPC4VZZg0jK+sMfrvrmGm0fcVXh7LYBB8YY69UvblmWTxy GiSh7AQAA X-Change-ID: 20260728-drm_pending_vblank_event_leak-a36cedb296ba To: Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter Cc: dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Melissa Wen , kernel-dev@igalia.com, sashiko-bot@kernel.org, Thadeu Lima de Souza Cascardo X-Mailer: b4 0.16-dev-62088 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. Reported-by: sashiko-bot@kernel.org Closes: https://sashiko.dev/#/patchset/20260727-drm_crtc_atomic_commit_leak= -v1-1-23d9948a9d7c@igalia.com?part=3D1 Fixes: 92c715fca907 ("drm/atomic: Fix double free in drm_atomic_state_defau= lt_clear") Signed-off-by: Thadeu Lima de Souza Cascardo Reviewed-by: Melissa Wen --- 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_le= ak-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_le= ak-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_le= ak-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; =20 + ret =3D -ENOMEM; + f =3D krealloc(*fence_state, sizeof(**fence_state) * (*num_fences + 1), GFP_KERNEL); if (!f) - return -ENOMEM; + goto err_free_event; =20 memset(&f[*num_fences], 0, sizeof(*f)); =20 @@ -1470,12 +1472,12 @@ static int prepare_signaling(struct drm_device *dev, =20 fence =3D drm_crtc_create_fence(crtc); if (!fence) - return -ENOMEM; + goto err_free_event; =20 ret =3D setup_out_fence(&f[(*num_fences)++], fence); if (ret) { dma_fence_put(fence); - return ret; + goto err_free_event; } =20 crtc_state->event->base.fence =3D fence; @@ -1531,6 +1533,11 @@ static int prepare_signaling(struct drm_device *dev, } =20 return 0; + +err_free_event: + drm_event_cancel_free(dev, &crtc_state->event->base); + crtc_state->event =3D NULL; + return ret; } =20 static void complete_signaling(struct drm_device *dev, --- base-commit: 4d4be202165e832d74849b4a68e289a2a377039c change-id: 20260728-drm_pending_vblank_event_leak-a36cedb296ba Best regards, -- =20 Thadeu Lima de Souza Cascardo