From nobody Mon Sep 28 20:17:33 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 0C4C23BED2B for ; Mon, 17 Aug 2026 21:36:38 +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=1787002601; cv=none; b=SuabRoFo6cVh36i3yGtJ1hDmbCDzTJu8hFA5qVWaU1AYtxP0iJUIR/6C0jX1B6BHVBhj+TjPxClJ7yQj3rnNyEmWTiiPx7fp1mpYbb3K8uTV+QeV2m3pI6eNg8+wpzz9A7MIvdxgLxZZeOTa480knLDUqRSQ+lRzufgH97SPoY4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787002601; c=relaxed/simple; bh=XB12/8ozUTyDAqxylFejmP7xYU3N2ozCbUV2cbWDV4w=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:To:Cc; b=CmE9gm+isTaUvoWKPlUA/RJ0CKUPJbg6/piyaEQPJfnxWRowbfnqiiIli6Yjbj2XeLmTMSBGI6Jm0jUneEk+YsjhAwBJ0i557wOxKochdMWfdxas19uuZ5L3oXaTb3E09xT1bNkij5kMUlRQbSTflFqrV+/IGyl1hif32U9zV7c= 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=msHpgQmQ; 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="msHpgQmQ" 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=mDtI+KRD9GYTHqW+CtkJ5LkZHCknM50k9+DwNYXj7OA=; b=msHpgQmQQ0efLcccm4TYuLcVOe y1zK9iwDPOrn6su51M83MfVwZPpc/NQ2AJKi32wm9TuIkBKOmw2M2Yy41lVTH+2SkPPLJW3wTpbzK R6B04WxplrB4APUYpf38vgfSzswo5zmNZicKeG12bl3zfsYVM1lIqr8a0lbfdjB+9O3reTE9gCCwR tw3qx7HbS18G6/+lDFLUiOtY/CEQ/+Jn9f5Y5c6Qu76Tgahe5xCDKWZFVhLWjC9dr/KOZUXYVmpvh njl3Tu0wdXIz2EyB8wbeXjWpQVvIpC2d+QOL1FKbgxCFsmoDV7Stx7nCBldB913MQoOH8KnnNeoUU 5fv7PUcQ==; Received: from 179-125-92-196-dinamico.pombonet.net.br ([179.125.92.196] 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 1ww50U-0052VL-Fp; Mon, 17 Aug 2026 23:36:34 +0200 From: Thadeu Lima de Souza Cascardo Date: Mon, 17 Aug 2026 18:36:18 -0300 Subject: [PATCH v3] 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: <20260817-drm_pending_vblank_event_leak-v3-1-7582b24447d0@igalia.com> X-B4-Tracking: v=1; b=H4sIANN+g2oC/43OzQ6CMBAE4FcxPVtTCvLjyfcwhmzpAitQSIuNh vDuAl70pMdJJt/MxBxaQsdOu4lZ9OSoN0sI9ztW1GAq5KSXzKSQsUhkyrXt8gGNJlPlXrVgmhw 9mjFvERoOYVygVjKLFbDFGCyW9Nj8y/Wd3V3dsBhXdG3U5MbePrcDPlh7/275gAdcpJHMVCaFC uIzVdASHIq+Y+uYl59c9ouTCwdHkUQAKBJdfnHzPL8A9pVK1ywBAAA= 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 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 | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/drm_atomic_uapi.c b/drivers/gpu/drm/drm_atomic= _uapi.c index 1050dddadb17..0aba33824595 100644 --- a/drivers/gpu/drm/drm_atomic_uapi.c +++ b/drivers/gpu/drm/drm_atomic_uapi.c @@ -1426,6 +1426,7 @@ static int prepare_signaling(struct drm_device *dev, struct drm_crtc_state *crtc_state; struct drm_connector *conn; struct drm_connector_state *conn_state; + struct drm_pending_vblank_event *e; int i, c =3D 0, ret; =20 if (arg->flags & DRM_MODE_ATOMIC_TEST_ONLY) @@ -1437,8 +1438,6 @@ static int prepare_signaling(struct drm_device *dev, fence_ptr =3D get_out_fence_for_crtc(crtc_state->state, crtc); =20 if (arg->flags & DRM_MODE_PAGE_FLIP_EVENT || fence_ptr) { - struct drm_pending_vblank_event *e; - e =3D create_vblank_event(crtc, arg->user_data); if (!e) return -ENOMEM; @@ -1447,7 +1446,7 @@ static int prepare_signaling(struct drm_device *dev, } =20 if (arg->flags & DRM_MODE_PAGE_FLIP_EVENT) { - struct drm_pending_vblank_event *e =3D crtc_state->event; + e =3D crtc_state->event; =20 if (!file_priv) continue; @@ -1464,11 +1463,14 @@ static int prepare_signaling(struct drm_device *dev, if (fence_ptr) { struct dma_fence *fence; struct drm_out_fence_state *f; + e =3D crtc_state->event; + + ret =3D -ENOMEM; =20 f =3D krealloc(*fence_state, sizeof(**fence_state) * (*num_fences + 1), GFP_KERNEL); if (!f) - return -ENOMEM; + goto error; =20 memset(&f[*num_fences], 0, sizeof(*f)); =20 @@ -1477,12 +1479,12 @@ static int prepare_signaling(struct drm_device *dev, =20 fence =3D drm_crtc_create_fence(crtc); if (!fence) - return -ENOMEM; + goto error; =20 ret =3D setup_out_fence(&f[(*num_fences)++], fence); if (ret) { dma_fence_put(fence); - return ret; + goto error; } =20 crtc_state->event->base.fence =3D fence; @@ -1538,6 +1540,11 @@ static int prepare_signaling(struct drm_device *dev, } =20 return 0; + +error: + drm_event_cancel_free(dev, &e->base); + crtc_state->event =3D NULL; + return ret; } =20 static void complete_signaling(struct drm_device *dev, --- base-commit: 5d2584e2ffaabf2d420edcb2d120209e151f8dce change-id: 20260728-drm_pending_vblank_event_leak-a36cedb296ba Best regards, -- =20 Thadeu Lima de Souza Cascardo