From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AG47ELsSkZWlJo4LE3x9UvcY/pCt0jEWgiTwsoKfz2Mv+9qlXQRWNw58sssPSvce+yj2y9kOpSrc ARC-Seal: i=1; a=rsa-sha256; t=1520641290; cv=none; d=google.com; s=arc-20160816; b=L2F2hkvV2Q7bE2AXaTTUKy0jCjDcpjSS2a5KaIaB5WPJ3sWFK9zQabH/PDuR5dWVlV GPE2y1ejVXUFZCzRkoN7M4eACkXtGHAZZNM9A/8a4h7M/aSYSNn2vLyTdAcZ2c6I2mez 4chVDTl5Rag8ttdMQGDVre+QUkVo5TeLQYIFYGN2Ah+05MMrHQ16PGzGB+FC5xzhE32B uu4BzEZoU0eTOCrOFn+kG4TkI+Gg5SV6O/70Diq65Oyjvn3P++DC+iwVfpfMC2D8Npo6 aH275C1QOd8Gxj2mVLeMfyX/kIlb8jO385ddfXKCyCGjphXKn0Lta5UGF4UmIycINZDI xCZw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:user-agent:references:in-reply-to:message-id:date :subject:cc:to:from:arc-authentication-results; bh=Q+Z2vL2u/NaAW7kobK2oeLXFawnJWU2iBXWyjQPQUt8=; b=PjW8i/EvHmwu0tWU6iEOdn28bny/wZA7P7vWIiDcoPk/LBXUXyk3uiYR8jG3xLEhdQ PAZ3AIqfiIUOffqfamC8FdfNYZVn/x57CUs8EPhCPp1Z+j2PREHkhZ+j9x1RiNVXJPi1 e5BYHVk+1p1K1yztleqYXL1R078qdlWs/uOD/6tjgfXtXC3iQ61DNhcRJjcb/ose5ND1 Tf+89gEGEajiLYr/xEMZV2X1z8OVzeavxeHuGnSq+slKItbDt0KID8nsq2DR0OXMSLtc DsYspO7fsvP31wCMBnBeqMpEIbsbJUKmYZ+tKJbdizUKx3SCaeFL2R86KLvr44mrNKIr Dh7w== ARC-Authentication-Results: i=1; mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 185.236.200.248 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org Authentication-Results: mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 185.236.200.248 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jeremy Boone , James Bottomley , Jarkko Sakkinen , James Morris Subject: [PATCH 4.9 04/65] tpm_tis: fix potential buffer overruns caused by bit glitches on the bus Date: Fri, 9 Mar 2018 16:18:04 -0800 Message-Id: <20180310001825.268027029@linuxfoundation.org> X-Mailer: git-send-email 2.16.2 In-Reply-To: <20180310001824.927996722@linuxfoundation.org> References: <20180310001824.927996722@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-LABELS: =?utf-8?b?IlxcU2VudCI=?= X-GMAIL-THRID: =?utf-8?q?1594507961790979150?= X-GMAIL-MSGID: =?utf-8?q?1594507961790979150?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jeremy Boone commit 6bb320ca4a4a7b5b3db8c8d7250cc40002046878 upstream. Discrete TPMs are often connected over slow serial buses which, on some platforms, can have glitches causing bit flips. In all the driver _recv() functions, we need to use a u32 to unmarshal the response size, otherwise a bit flip of the 31st bit would cause the expected variable to go negative, which would then try to read a huge amount of data. Also sanity check that the expected amount of data is large enough for the TPM header. Signed-off-by: Jeremy Boone Cc: stable@vger.kernel.org Signed-off-by: James Bottomley Tested-by: Jarkko Sakkinen Reviewed-by: Jarkko Sakkinen Signed-off-by: Jarkko Sakkinen Signed-off-by: James Morris Signed-off-by: Greg Kroah-Hartman --- drivers/char/tpm/tpm_tis_core.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/drivers/char/tpm/tpm_tis_core.c +++ b/drivers/char/tpm/tpm_tis_core.c @@ -208,7 +208,8 @@ static int tpm_tis_recv(struct tpm_chip { struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev); int size = 0; - int expected, status; + int status; + u32 expected; if (count < TPM_HEADER_SIZE) { size = -EIO; @@ -223,7 +224,7 @@ static int tpm_tis_recv(struct tpm_chip } expected = be32_to_cpu(*(__be32 *) (buf + 2)); - if (expected > count) { + if (expected > count || expected < TPM_HEADER_SIZE) { size = -EIO; goto out; }