From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AIpwx49wtbnm389lOo7IGWr7O+Zw+8DPdjGqILnPCNfGlAX9l4uEQHc6XSYx+Gu8YVjyEuyaBIhS ARC-Seal: i=1; a=rsa-sha256; t=1522168957; cv=none; d=google.com; s=arc-20160816; b=HOBarIKf2x58hRzLQcJfJmqducX7tlZ8zGcXPoyFRYy+fmpm1HABPhA4lFFOZnLf5t CBCRZrVOI4eV04OHQKpUe8Lnq9iO8afBOkuywbWmDKanQslVsZZazXebLNMjr6yA/r6r 1PpElPdU7BCFOrUoiMfHoLeqE15jafPOHmg4xvIphUCOaKm2/eLGTyQRO6YIOY9sEZ/L ylNPuNSv4BsWVE70Wx1zKpwqf5YvCMnjen0q1RyyGtal17xfaSX0U07kaLyWDQD6mWoM 7XXudvSi1vQ+T/uaZkbg1movL2xZMK90MMisLdPB6wQhEUClj+qDZMMk06z8NEo6dJiA WqsQ== 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=72jCOWIsDYzQE4hqDOEUThbeE80+3Hmt+rO5Bmk7Hjk=; b=AZQjh4I52954tvz1WAe2VRYvC0O278sVz0+pVCI1fckrnFW+F94jEDleKQwWKcKYBw yeWxjY8Lur0K9E/ygtRgxtW/NrzuIhCXE7wLKRDJEnscNwKl8Dsfw2N/XuzRnbrksxE+ 4uFHO4iECjRhtYRcqZCRqPqgYXcgDdoOgxUbF07Ew0ktp3iavMeZYufK5ipUwk5k5yQS GrlCmG01jL6lmALn68RWPLvK7bHnJHOcDoeR64c9y2lR0MHmrSL68Djc/a5xPECM+ZZF BmF2xucDFDNbXNQJQtwt+31i2vxN1dZIqTsEs3680PVrvA/UHCJkdKgO+1EW4y131MSs XRIA== ARC-Authentication-Results: i=1; mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.61.202 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 90.92.61.202 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, Dan Carpenter Subject: [PATCH 4.15 074/105] staging: ncpfs: memory corruption in ncp_read_kernel() Date: Tue, 27 Mar 2018 18:27:54 +0200 Message-Id: <20180327162802.508474143@linuxfoundation.org> X-Mailer: git-send-email 2.16.3 In-Reply-To: <20180327162757.813009222@linuxfoundation.org> References: <20180327162757.813009222@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?1596109021146013259?= X-GMAIL-MSGID: =?utf-8?q?1596109836398497990?= 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: Dan Carpenter commit 4c41aa24baa4ed338241d05494f2c595c885af8f upstream. If the server is malicious then *bytes_read could be larger than the size of the "target" buffer. It would lead to memory corruption when we do the memcpy(). Reported-by: Dr Silvio Cesare of InfoSect Signed-off-by: Dan Carpenter Cc: stable Signed-off-by: Greg Kroah-Hartman --- fs/ncpfs/ncplib_kernel.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/fs/ncpfs/ncplib_kernel.c +++ b/fs/ncpfs/ncplib_kernel.c @@ -981,6 +981,10 @@ ncp_read_kernel(struct ncp_server *serve goto out; } *bytes_read = ncp_reply_be16(server, 0); + if (*bytes_read > to_read) { + result = -EINVAL; + goto out; + } source = ncp_reply_data(server, 2 + (offset & 1)); memcpy(target, source, *bytes_read);