From patchwork Mon May 15 22:25:54 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jarkko Sakkinen X-Patchwork-Id: 13242305 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 49128C77B7D for ; Mon, 15 May 2023 22:26:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243053AbjEOW0F (ORCPT ); Mon, 15 May 2023 18:26:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39124 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234623AbjEOW0E (ORCPT ); Mon, 15 May 2023 18:26:04 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EA1D2A3; Mon, 15 May 2023 15:26:03 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 86E23623F6; Mon, 15 May 2023 22:26:03 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 644E7C433D2; Mon, 15 May 2023 22:26:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1684189562; bh=mgXb0mwxaOmdxBcgoHsqCUvWmllYoas8WLQZmW80/0U=; h=From:To:Cc:Subject:Date:From; b=tljRDJNRgEs51+Df/dmJVTibiTt1wcAE1beiT9OvcO/Cm+pyikMJrPEY7Ow/IoO2d bUGy2qRQc6S0rEP10IdJk5MKv+FffbtjlIMNKpOWdMyMUGuS/s9z0zPSFiDWcAz6h2 JMl0WdK67n5pWI2IQgtE5jaUJyz61CK2XH2Y3QSQX0r/mveGntgl/kUYHds+phMic9 blq8A1GjpsF6reZQaCYe2I66VDmCXsGpQHOhsNOXQdfM/AeFcPn/hEl5QCodVAjM0F kIcB7I0KbNEvbnaLGiacadd+aMGNiIjO9xqbmqMkqRubhauD8tjKp+NKg3joFabTnJ S5ws7+8XA/xEQ== From: Jarkko Sakkinen To: linux-integrity@vger.kernel.org, Peter Huewe , Jarkko Sakkinen , Jason Gunthorpe , Stefan Berger Cc: Jarkko Sakkinen , stable@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2] tpm: tpm_vtpm_proxy: fix a race condition in /dev/vtpmx creation Date: Tue, 16 May 2023 01:25:54 +0300 Message-Id: <20230515222554.2783592-1-jarkko@kernel.org> X-Mailer: git-send-email 2.39.2 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org From: Jarkko Sakkinen /dev/vtpmx is made visible before 'workqueue' is initialized, which can lead to a memory corruption in the worst case scenario. Address this by initializing 'workqueue' as the very first step of the driver initialization. Cc: stable@vger.kernel.org Fixes: 6f99612e2500 ("tpm: Proxy driver for supporting multiple emulated TPMs") Signed-off-by: Jarkko Sakkinen Reviewed-by: Stefan Berger --- v2: - Replace vtpmx_cleanup() with destroy_workqueue(): https://lore.kernel.org/linux-integrity/CSLCEYDKKWWE.36POIXVT65SLE@suppilovahvero/ - Fix typo: https://lore.kernel.org/linux-integrity/4651cf1c-423d-05c2-b4c3-9d829a2eadf4@linux.ibm.com/ --- drivers/char/tpm/tpm_vtpm_proxy.c | 30 +++++++----------------------- 1 file changed, 7 insertions(+), 23 deletions(-) diff --git a/drivers/char/tpm/tpm_vtpm_proxy.c b/drivers/char/tpm/tpm_vtpm_proxy.c index 5c865987ba5c..30e953988cab 100644 --- a/drivers/char/tpm/tpm_vtpm_proxy.c +++ b/drivers/char/tpm/tpm_vtpm_proxy.c @@ -683,37 +683,21 @@ static struct miscdevice vtpmx_miscdev = { .fops = &vtpmx_fops, }; -static int vtpmx_init(void) -{ - return misc_register(&vtpmx_miscdev); -} - -static void vtpmx_cleanup(void) -{ - misc_deregister(&vtpmx_miscdev); -} - static int __init vtpm_module_init(void) { int rc; - rc = vtpmx_init(); - if (rc) { - pr_err("couldn't create vtpmx device\n"); - return rc; - } - workqueue = create_workqueue("tpm-vtpm"); if (!workqueue) { pr_err("couldn't create workqueue\n"); - rc = -ENOMEM; - goto err_vtpmx_cleanup; + return -ENOMEM; } - return 0; - -err_vtpmx_cleanup: - vtpmx_cleanup(); + rc = misc_register(&vtpmx_miscdev); + if (rc) { + pr_err("couldn't create vtpmx device\n"); + destroy_workqueue(workqueue); + } return rc; } @@ -721,7 +705,7 @@ static int __init vtpm_module_init(void) static void __exit vtpm_module_exit(void) { destroy_workqueue(workqueue); - vtpmx_cleanup(); + misc_deregister(&vtpmx_miscdev); } module_init(vtpm_module_init);