From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AG47ELvirmPTE0IB/Hixom332JupQVvgYPFqsZ1jHGoIe1laawbCNL74QHp77BCfTpNRo9THFU6s ARC-Seal: i=1; a=rsa-sha256; t=1520641214; cv=none; d=google.com; s=arc-20160816; b=n8yyX5AIxvUBgWo55Qj4zbxiNdhWM9CuYLEAEtajVi0oRH9pe6EeV1ilTsE2V/pOKJ pg+rD8fUgvUqilhtq0IJPqoiht6acws1FNfrWGRvS0eo0FBA6NuFlSjlrIHdtjrC73CJ ZxItznZdYh2OzY4IzYaLvkNHbKaDpvUV0ErqNaCp9dCbRhKMuavoaaH05xK1y8L2u/1s Mm9Ac39rIsLCh+c1Z8DFDzYXOJB3kM2JgIoBXP1Z73Wt7xpmm8JJxDdc1kzWDf6FLN1b cfkejRi/70+SWMyjVq251tAGTvAbV9G9lKdgScEfnJXITqvX6iiTeJxf93b3HBsll2xU gC8g== 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=dTeY9JFiuNdgLheszxAi9SGOtflXBYUPurApOde3iLw=; b=CiloSJnvtsCWG8zqYAU/3IkUW2ot0gWko+h2HbG9MRaKT75n09BwotBnRZHC19vQ3e jW7tthoN6Yz3QvmCfcANNArNCIgvd21c2Y1K2PzsqwUVAHeuxDsG7edC3IYgTT2xGvuI czy9NQNoypezGF57CkId2ifVje5/mStF3ztQZayXn2ImzL8zh9Jy3OJsvTopfz+ArI5v XH+Nq48QpGLzIUW3idGQXZXxLc6IjANrGcQVUcupB+6pHTH9HtpGIVe/wVw0SyIV4poY Sm/k+VMJZLv4qjEEBoT62mQv0bJXf2dsOM6n8PrzsNcRZLRk7gmxabhrzdgixCWeWeJu kw2Q== 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 4.4 03/36] tpm_i2c_nuvoton: fix potential buffer overruns caused by bit glitches on the bus Date: Fri, 9 Mar 2018 16:18:19 -0800 Message-Id: <20180310001807.395175410@linuxfoundation.org> X-Mailer: git-send-email 2.16.2 In-Reply-To: <20180310001807.213987241@linuxfoundation.org> References: <20180310001807.213987241@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?1594507802508927264?= X-GMAIL-MSGID: =?utf-8?q?1594507881980610203?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.4-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 @@ -267,7 +267,11 @@ 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 */ @@ -309,7 +313,7 @@ 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;