From mboxrd@z Thu Jan 1 00:00:00 1970 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 82DA2C3527B for ; Fri, 25 Mar 2022 15:27:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1377240AbiCYP2f (ORCPT ); Fri, 25 Mar 2022 11:28:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42866 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1378227AbiCYPZO (ORCPT ); Fri, 25 Mar 2022 11:25:14 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5B366ECC5A; Fri, 25 Mar 2022 08:20:05 -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 E1D5C611FB; Fri, 25 Mar 2022 15:20:04 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C4514C340EE; Fri, 25 Mar 2022 15:20:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1648221604; bh=bLyHvRHuwpHkVvuattikF0PH4TZTbUXMmVmmup3vp7E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=SzfWQ48fZlmtFpK064O+kt66fgj2ljc39sNHgSzDOj16YmnolNUi0Vq4YX7dOilik yAEnAHZlZWHn1k3Tm3aGz6tQyX+XnlSADH6OoWBntK0u/b5L4Ls5zUIFUetpVcxULr yyOA2CNLp0RapnkvKMa0bEcF4c5O/AHDnQpu6KQw= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, James Bottomley , Jarkko Sakkinen Subject: [PATCH 5.17 36/39] tpm: use try_get_ops() in tpm-space.c Date: Fri, 25 Mar 2022 16:14:51 +0100 Message-Id: <20220325150421.277908724@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220325150420.245733653@linuxfoundation.org> References: <20220325150420.245733653@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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); }