From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AG47ELszkOkasGmfKZ1dQdtXjWMVZWnhPinV17bGACrmU8QeGkvB40Q2QxF+HnGdxJ/+NUEOcAVW ARC-Seal: i=1; a=rsa-sha256; t=1520451586; cv=none; d=google.com; s=arc-20160816; b=WxSQHhl49KhobNlb8vxj8m7vwvtEpj4Bkt4lhKjEXvxzC2Pze6qwsHB2i5F+jsynhZ QB0nrsZtcjeDEAWaOlvzQsh74fvPiFM+PQjg8W0CvoepTgL8oZAf8j0OoO/SsNPgL9LC 6vmSnGyBpqGnZEEnuWYcN53lvhPcJhuyBbcp8xt9p9Uo2Ks/Zj5Yh5ZK9UcS8mDvhhvR ICzoDn08fdjrUV1HguWkzU+LFtlM0BHRxrnzJzt1UEyceosxXVlhzyvICww27ehlA3xl wCGBtAnPmhM6IU/aa3BrGnnSUpkoIeDSrPAjyX2S2g5XzLQ7yCSF0t5I2GjVk8d2SAAm apwg== 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=ShfvcTMy72EHezh7Hs3sOTNHUYQP7nypYbz/tCGgCtc=; b=k2rGYXR25e0jhMl/YddTpuTT2TN4wYHcJm19BKOCysLhrM2pqWd8IhnoeO/ATD0ISk AlTITD7Nsu70X9DNGDBbt4Y+K+ME0f5UjpX/AKsXPrFLq10nMFzTmymHcnN5AAd47hTp BP2/u6VcMpG6jeorkA+/DY8TNJSwYSULVY/QRESdD1yHr05LIn5Yn/P3THALOFxao4X8 FwLE/BYGVpIzZywwSVxmSk7lGZrxYg59vh0Bmf69Pfzy6EaQEiTCOWmQ6+KGoOOcE7LM Y5q52VCpOuYjD8+A7IzraRbRnf1hGxXRbpEVpDns6iRZAvUDkczomvRxiJ8DtI2sj2BE qTIg== 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 4.15 011/122] tpm_i2c_nuvoton: fix potential buffer overruns caused by bit glitches on the bus Date: Wed, 7 Mar 2018 11:37:03 -0800 Message-Id: <20180307191730.829757514@linuxfoundation.org> X-Mailer: git-send-email 2.16.2 In-Reply-To: <20180307191729.190879024@linuxfoundation.org> References: <20180307191729.190879024@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?1594309042312731785?= X-GMAIL-MSGID: =?utf-8?q?1594309042312731785?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jeremy Boone commit f9d4d9b5a5ef2f017bc344fb65a58a902517173b 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 Reviewed-by: Jarkko Sakkinen Signed-off-by: Jarkko Sakkinen Signed-off-by: James Morris Signed-off-by: Greg Kroah-Hartman --- drivers/char/tpm/tpm_i2c_nuvoton.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) --- a/drivers/char/tpm/tpm_i2c_nuvoton.c +++ b/drivers/char/tpm/tpm_i2c_nuvoton.c @@ -281,7 +281,11 @@ static int i2c_nuvoton_recv(struct tpm_c struct device *dev = chip->dev.parent; struct i2c_client *client = to_i2c_client(dev); s32 rc; - int expected, status, burst_count, retries, size = 0; + int status; + int burst_count; + int retries; + int size = 0; + u32 expected; if (count < TPM_HEADER_SIZE) { i2c_nuvoton_ready(chip); /* return to idle */ @@ -323,7 +327,7 @@ static int i2c_nuvoton_recv(struct tpm_c * to machine native */ expected = be32_to_cpu(*(__be32 *) (buf + 2)); - if (expected > count) { + if (expected > count || expected < size) { dev_err(dev, "%s() expected > count\n", __func__); size = -EIO; continue;