From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AG47ELu8f00GA9kU7jN/aE52Z38clBj1PqgNUM80Q2yVi2FhCj1giNLmIxmTWtb9RYDIXrrAGC9R ARC-Seal: i=1; a=rsa-sha256; t=1520451588; cv=none; d=google.com; s=arc-20160816; b=WUDpdIA2E7z5bNtomHsqF1lq53Uh4RVAZLD2x2Cgqcip7+T8f53BGJoAJ8oUbiMGid 807D7fWkkWnfjDWeb5DrAc7Sct1Szl7YACX1wLvJlppyXYCA0HB0Y4sa8ALjWDijfw1N JJ5j/0uEJMxSVXLvs7r5J4z8wNIxKv4nJpHW/1lyd67483kNLt7Kn9D2B6ZCl5nxVneo 1JAStMxU6EIxx5JgF9/FUfYqf1ltJ/ySEXXxAeZiRYBkU1kYyFSxGPnT+CdMEAF5YhrG bHTwBiCPBp6KarYW2B5UajWSmYQSKkb56IlrOeREbnSeo4RbZixRekwb8IZhEHLZAhyk nrwA== 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=S8q+DM+PZKKLS/neJJovvrwEz3o8olyOEeYerAGqeFg=; b=TEi+V7k/snrohryUhD4dZU/tV8wuz2BKbLFIKVyVNqTDJ05nOAYDoVEwbdR31k49Gk 9LnLxVPlvF8v5hAM/jG7xfcwxkyakRrMbc1wdunl7oa4eUFYt9bPn6QUWoHrAUr/3mth Op+Y9pvfIgSnvbYP8jcLZgD1jC4SpMa9oudr2qdxOymUR//HF+Owgrxap/giIcBrwby3 +4rdrT8c2CoUsCkg+uhsgn6I91Cm9FYqElwm/V5kzW7vnOPeiJ4ahpEz6hJycKLwbsq5 dCMSNjxoymJ5qHXM9NMK0Q8qZim4RTAMCPVhGf35eq0sVhaRD7vBtJCnXlTTmT5g+Y8Q nAdg== 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 4.15 012/122] tpm_tis: fix potential buffer overruns caused by bit glitches on the bus Date: Wed, 7 Mar 2018 11:37:04 -0800 Message-Id: <20180307191730.988938822@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?1594309045256523851?= X-GMAIL-MSGID: =?utf-8?q?1594309045256523851?= 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 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 @@ -202,7 +202,8 @@ 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; @@ -217,7 +218,7 @@ 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; }