linux-kernel - [PATCH v14 3/7] tpm: tpm_tis: Rewrite "tpm_tis_req

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20210913144351.101167-4-amirmizi6@gmail.com>
Date:   Mon, 13 Sep 2021 17:43:47 +0300
From:   amirmizi6@...il.com
To:     Eyal.Cohen@...oton.com, jarkko@...nel.org, oshrialkoby85@...il.com,
        alexander.steffen@...ineon.com, robh+dt@...nel.org,
        mark.rutland@....com, peterhuewe@....de, jgg@...pe.ca,
        arnd@...db.de, gregkh@...uxfoundation.org, benoit.houyere@...com,
        eajames@...ux.ibm.com, joel@....id.au
Cc:     devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-integrity@...r.kernel.org, oshri.alkoby@...oton.com,
        tmaimon77@...il.com, gcwilson@...ibm.com, kgoldman@...ibm.com,
        Dan.Morav@...oton.com, oren.tanami@...oton.com,
        shmulik.hager@...oton.com, amir.mizinski@...oton.com,
        Amir Mizinski <amirmizi6@...il.com>
Subject: [PATCH v14 3/7] tpm: tpm_tis: Rewrite "tpm_tis_req_canceled()"

From: Amir Mizinski <amirmizi6@...il.com>

tpm_tis_req_canceled() function is used to check if the caller requested
to abort the current operation. It was found that in some cases
tpm_tis_req_canceled() wrongly returned true.
Since a cancel request sets the TPM_STS.commandReady field to TRUE, the
tpm_tis_req_canceled() function should check only the TPM_STS.commandReady
field value.
The case for TPM_VID_WINBOND is wrong and was therefore removed.

Also, the default comparison is wrong. Only cmdReady bit needs to be
compared instead of the full lower status register byte.

Fixes: 1f866057291f (tpm: Fix cancellation of TPM commands (polling mode))
Signed-off-by: Amir Mizinski <amirmizi6@...il.com>
---
 drivers/char/tpm/tpm_tis_core.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
index b34e59b..4145758 100644
--- a/drivers/char/tpm/tpm_tis_core.c
+++ b/drivers/char/tpm/tpm_tis_core.c
@@ -650,13 +650,11 @@ static bool tpm_tis_req_canceled(struct tpm_chip *chip, u8 status)
 	struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
 
 	switch (priv->manufacturer_id) {
-	case TPM_VID_WINBOND:
-		return ((status == TPM_STS_VALID) ||
-			(status == (TPM_STS_VALID | TPM_STS_COMMAND_READY)));
 	case TPM_VID_STM:
 		return (status == (TPM_STS_VALID | TPM_STS_COMMAND_READY));
 	default:
-		return (status == TPM_STS_COMMAND_READY);
+		return ((status & TPM_STS_COMMAND_READY) ==
+			TPM_STS_COMMAND_READY);
 	}
 }
 
-- 
2.7.4