From patchwork Fri Mar 25 15:05:08 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 554292 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 17D21C433F5 for ; Fri, 25 Mar 2022 15:11:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1359837AbiCYPMg (ORCPT ); Fri, 25 Mar 2022 11:12:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44620 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1359857AbiCYPMC (ORCPT ); Fri, 25 Mar 2022 11:12:02 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2BD7662A2F; Fri, 25 Mar 2022 08:09:01 -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 ams.source.kernel.org (Postfix) with ESMTPS id D57B7B82904; Fri, 25 Mar 2022 15:08:47 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 23280C340F4; Fri, 25 Mar 2022 15:08:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1648220926; bh=bLyHvRHuwpHkVvuattikF0PH4TZTbUXMmVmmup3vp7E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=c/qUIwmzbcEDQLlpZ4Nm+diQd+jGIEoqRFYNK8zzZZD21jAJviDBy2tIsumPdYWrU Ktv6PIj4cpw66QZgPQ0uXSi4SVj4UMt3kH3UDtKn5XDa8nRO3G6Q8m6PbjDxcEIcoD q1bRqJZV6tjowZtSj00E8EGRHUvvC9V3WLJakW1E= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, James Bottomley , Jarkko Sakkinen Subject: [PATCH 5.4 28/29] tpm: use try_get_ops() in tpm-space.c Date: Fri, 25 Mar 2022 16:05:08 +0100 Message-Id: <20220325150419.395229464@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220325150418.585286754@linuxfoundation.org> References: <20220325150418.585286754@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: James Bottomley commit fb5abce6b2bb5cb3d628aaa63fa821da8c4600f9 upstream. As part of the series conversion to remove nested TPM operations: https://lore.kernel.org/all/20190205224723.19671-1-jarkko.sakkinen@linux.intel.com/ exposure of the chip->tpm_mutex was removed from much of the upper level code. In this conversion, tpm2_del_space() was missed. This didn't matter much because it's usually called closely after a converted operation, so there's only a very tiny race window where the chip can be removed before the space flushing is done which causes a NULL deref on the mutex. However, there are reports of this window being hit in practice, so fix this by converting tpm2_del_space() to use tpm_try_get_ops(), which performs all the teardown checks before acquring the mutex. Cc: stable@vger.kernel.org # 5.4.x Signed-off-by: James Bottomley Reviewed-by: Jarkko Sakkinen Signed-off-by: Jarkko Sakkinen Signed-off-by: Greg Kroah-Hartman --- drivers/char/tpm/tpm2-space.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) --- a/drivers/char/tpm/tpm2-space.c +++ b/drivers/char/tpm/tpm2-space.c @@ -58,12 +58,12 @@ int tpm2_init_space(struct tpm_space *sp void tpm2_del_space(struct tpm_chip *chip, struct tpm_space *space) { - mutex_lock(&chip->tpm_mutex); - if (!tpm_chip_start(chip)) { + + if (tpm_try_get_ops(chip) == 0) { tpm2_flush_sessions(chip, space); - tpm_chip_stop(chip); + tpm_put_ops(chip); } - mutex_unlock(&chip->tpm_mutex); + kfree(space->context_buf); kfree(space->session_buf); }