From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AB8JxZpDiXlwr9vqCVZfWVEi2WiC1CdKJZuci6638ThbrqeR8x7TiUUtP25ql+joc14HoD+diDyA ARC-Seal: i=1; a=rsa-sha256; t=1526281189; cv=none; d=google.com; s=arc-20160816; b=Ex78I8VSstBsjRBI2H3ZRCVQX5lIWekC3mUui7Mqhje09mp9CHkV8v5XqglWazsSZO OoFWzXDquqKRuPPnpfBE0nm7oVxOoCZESSJBHvcl1XyuW6RNOSv6yv2akP5cAstq5YyO xLGTN8hi63tQxeqUcneDIL3MYvjzT4Jxb8aaLWSO0vFemHJcsXiQnIFXUv14Yuz0b2GB NosCwtd7q3OmJugNSW8gNV3LDSVi8ADlEu/t9e4lQlfLrqJCvTbA9kvtc6fGLyy4GO/O eWmZxuaybHyTT2GNIIuWhcN4xF7nPm5hdiITR4wfN4ifpzjaOvP2OJE/ZtzGDoMkB8SW Cmqw== 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:dkim-signature:arc-authentication-results; bh=4YaZPgAy9gJLDEQaiKXVAm7jJmeuFSEcNRddXteM9IU=; b=PWkUwi1B9YLkcavHlSgaHwFw8LF+U+FtF4qKhPBEInCqH7b92l4g1Oj8t4kbS0dDG6 ugvUqu/UEaJUVSsDJZA7pGsBmFfTnPv0NiXOWGIUo7Kq1QZSkcqX+s8vqh/eG42LTbVd 8ddbmKYcWyK+VVxKQ2/hnF3kfjLtiBRNu7EBaf42WGvCjgcSofIrFw8vWjtBQQbWGfzg XfefxsVquw/fd2gW/+W3vAkI0oWQgTRF1bLHbP9eNguT1/Ad/rG36vIeEobgUhVryjIS lazUmkCUJUSgd5C0I4Pjsv7SJKZpTzgvy/KquDnTDSo88xwV6pDNBTEKQ4qFmkv1F0aw iuBw== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=M3tLs4oE; spf=pass (google.com: domain of srs0=ywzk=ib=linuxfoundation.org=gregkh@kernel.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=SRS0=ywzk=IB=linuxfoundation.org=gregkh@kernel.org Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=M3tLs4oE; spf=pass (google.com: domain of srs0=ywzk=ib=linuxfoundation.org=gregkh@kernel.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=SRS0=ywzk=IB=linuxfoundation.org=gregkh@kernel.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "Gustavo A. R. Silva" , "David S. Miller" Subject: [PATCH 4.16 50/72] net: atm: Fix potential Spectre v1 Date: Mon, 14 May 2018 08:49:07 +0200 Message-Id: <20180514064825.572953481@linuxfoundation.org> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180514064823.033169170@linuxfoundation.org> References: <20180514064823.033169170@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?1600421380423998410?= X-GMAIL-MSGID: =?utf-8?q?1600421823980581926?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.16-stable review patch. If anyone has any objections, please let me know. ------------------ From: Gustavo A. R. Silva commit acf784bd0ce257fe43da7ca266f7a10b837479d2 upstream. ioc_data.dev_num can be controlled by user-space, hence leading to a potential exploitation of the Spectre variant 1 vulnerability. This issue was detected with the help of Smatch: net/atm/lec.c:702 lec_vcc_attach() warn: potential spectre issue 'dev_lec' Fix this by sanitizing ioc_data.dev_num before using it to index dev_lec. Also, notice that there is another instance in which array dev_lec is being indexed using ioc_data.dev_num at line 705: lec_vcc_added(netdev_priv(dev_lec[ioc_data.dev_num]), Notice that given that speculation windows are large, the policy is to kill the speculation on the first load and not worry if it can be completed with a dependent load/store [1]. [1] https://marc.info/?l=linux-kernel&m=152449131114778&w=2 Cc: stable@vger.kernel.org Signed-off-by: Gustavo A. R. Silva Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/atm/lec.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) --- a/net/atm/lec.c +++ b/net/atm/lec.c @@ -41,6 +41,9 @@ static unsigned char bridge_ula_lec[] = #include #include +/* Hardening for Spectre-v1 */ +#include + #include "lec.h" #include "lec_arpc.h" #include "resources.h" @@ -687,8 +690,10 @@ static int lec_vcc_attach(struct atm_vcc bytes_left = copy_from_user(&ioc_data, arg, sizeof(struct atmlec_ioc)); if (bytes_left != 0) pr_info("copy from user failed for %d bytes\n", bytes_left); - if (ioc_data.dev_num < 0 || ioc_data.dev_num >= MAX_LEC_ITF || - !dev_lec[ioc_data.dev_num]) + if (ioc_data.dev_num < 0 || ioc_data.dev_num >= MAX_LEC_ITF) + return -EINVAL; + ioc_data.dev_num = array_index_nospec(ioc_data.dev_num, MAX_LEC_ITF); + if (!dev_lec[ioc_data.dev_num]) return -EINVAL; vpriv = kmalloc(sizeof(struct lec_vcc_priv), GFP_KERNEL); if (!vpriv)