From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 8458815C83 for ; Mon, 5 Dec 2022 19:28:33 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 09448C433D6; Mon, 5 Dec 2022 19:28:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1670268513; bh=6USEt5q+PYRxMT7sL9GpHFmTqM97lOjmpeoCAbl/kUI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ai7eVYvmsQ4h6Ss5cKfxgcMOY7kO5j15NlHIcxLyMNEYj7aF0PWVJVJoDeImnxS+B GF6vIIRKwmtem3JygmMHHqxHXfbVLIScskcPDM9UWGoptVppH4Dt0kxWp5TU96jgtV jmMET+mVXa0M6r1pZnsT14HoUV6mcS1LjdhtFSbg= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jan Dabros , Vlastimil Babka , "Jason A. Donenfeld" , Jarkko Sakkinen , Linus Torvalds Subject: [PATCH 6.0 122/124] char: tpm: Protect tpm_pm_suspend with locks Date: Mon, 5 Dec 2022 20:10:28 +0100 Message-Id: <20221205190811.911978386@linuxfoundation.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221205190808.422385173@linuxfoundation.org> References: <20221205190808.422385173@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Jan Dabros commit 23393c6461422df5bf8084a086ada9a7e17dc2ba upstream. Currently tpm transactions are executed unconditionally in tpm_pm_suspend() function, which may lead to races with other tpm accessors in the system. Specifically, the hw_random tpm driver makes use of tpm_get_random(), and this function is called in a loop from a kthread, which means it's not frozen alongside userspace, and so can race with the work done during system suspend: tpm tpm0: tpm_transmit: tpm_recv: error -52 tpm tpm0: invalid TPM_STS.x 0xff, dumping stack for forensics CPU: 0 PID: 1 Comm: init Not tainted 6.1.0-rc5+ #135 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.0-20220807_005459-localhost 04/01/2014 Call Trace: tpm_tis_status.cold+0x19/0x20 tpm_transmit+0x13b/0x390 tpm_transmit_cmd+0x20/0x80 tpm1_pm_suspend+0xa6/0x110 tpm_pm_suspend+0x53/0x80 __pnp_bus_suspend+0x35/0xe0 __device_suspend+0x10f/0x350 Fix this by calling tpm_try_get_ops(), which itself is a wrapper around tpm_chip_start(), but takes the appropriate mutex. Signed-off-by: Jan Dabros Reported-by: Vlastimil Babka Tested-by: Jason A. Donenfeld Tested-by: Vlastimil Babka Link: https://lore.kernel.org/all/c5ba47ef-393f-1fba-30bd-1230d1b4b592@suse.cz/ Cc: stable@vger.kernel.org Fixes: e891db1a18bf ("tpm: turn on TPM on suspend for TPM 1.x") [Jason: reworked commit message, added metadata] Signed-off-by: Jason A. Donenfeld Reviewed-by: Jarkko Sakkinen Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- drivers/char/tpm/tpm-interface.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/drivers/char/tpm/tpm-interface.c +++ b/drivers/char/tpm/tpm-interface.c @@ -401,13 +401,14 @@ int tpm_pm_suspend(struct device *dev) !pm_suspend_via_firmware()) goto suspended; - if (!tpm_chip_start(chip)) { + rc = tpm_try_get_ops(chip); + if (!rc) { if (chip->flags & TPM_CHIP_FLAG_TPM2) tpm2_shutdown(chip, TPM2_SU_STATE); else rc = tpm1_pm_suspend(chip, tpm_suspend_pcr); - tpm_chip_stop(chip); + tpm_put_ops(chip); } suspended: