From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AG47ELt1jKPqaePFSGN/nutGC2tXhriGQyENpjaDJ3xDEcuC1B/s85Mf4n9aeAH8tHhm0etMkBeD ARC-Seal: i=1; a=rsa-sha256; t=1520451649; cv=none; d=google.com; s=arc-20160816; b=pTcsdIGqoIsAdoNpEgdOzF3kf/VOLBo52lSF0Shsjt/sBmicxreEsFr+119gj6kUOC t+woLwLiRkHVlzjppKR3aeSY37D4jBGhoG+yLOPPwCdAvzYzGC1jChNm4IFqVdfL8Aq2 /KRSGI5fsADBraB1Mres661Uiopb701w6o8IwsPzzqBJ9O2UpTPOh7Nyh2kxO3CSC3gT CByNXjTzTaRJu9s6JfemB8vrduiWT4TNfx361usCbNAKusZ7LpQyIKl43aelD3tLJUO1 7sS3IcdbsLIDslfTHWTz0zwnHIxWpnPRRQZR5ItwPg4tmXSAG8ZlEFxy9aD8Ik4Jcxvq rrpQ== 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=IPtMTPEhCiGXD85ayXM857513sn9T9Qi16HATCPf5HU=; b=dCppqjsBuzdZlenyBLxn+In6Wy9NqKOBkOvtLPHskGz9RsJ3uooYSXTiGn8+s6HXT6 coHC6eJbzYEAVjCcpa9X3vrzMI0TI8q0iNzcLQL90Re8fbli7TpRULNt5rsGO2dnuHZZ YAkLAPv/jbtSbmjZ25P0BGlyTiLmDepEnd/X8A8Ry9wVzyuji0HuXFVGzo9F6I1Qd+yQ SfCcSWlaX5AZrqrp42uuDmPWzzUHtX4NKYu9ljzFRbhTgQ+o0JQGzKl3j0D35E1tlo7o AomVirHVe05Az4GnV68WcDxs02HF11swLtLllFCApP+FON7tLDUuUv/oJA0rQul9vK23 85EA== 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 4.15 008/122] tpm: st33zp24: fix potential buffer overruns caused by bit glitches on the bus Date: Wed, 7 Mar 2018 11:37:00 -0800 Message-Id: <20180307191730.479765771@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?1594309108141640090?= X-GMAIL-MSGID: =?utf-8?q?1594309108141640090?= 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 6d24cd186d9fead3722108dec1b1c993354645ff 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/st33zp24/st33zp24.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/char/tpm/st33zp24/st33zp24.c +++ b/drivers/char/tpm/st33zp24/st33zp24.c @@ -457,7 +457,7 @@ static int st33zp24_recv(struct tpm_chip size_t count) { int size = 0; - int expected; + u32 expected; if (!chip) return -EBUSY; @@ -474,7 +474,7 @@ static int st33zp24_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; }