From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AB8JxZqw8AwQhw/qRSwWyBZfMuwtY6inEAFFgFsbsOeE1vvdlUE/O5//Cdjmrr9CRVBU4ca7DEkk ARC-Seal: i=1; a=rsa-sha256; t=1526280768; cv=none; d=google.com; s=arc-20160816; b=NuLfpyuHH+8qHp6dZuFH/3wlROVcw2YhOhQixJRUhHSavgn5sMKJ7ht3Bz8U8Bxy04 mEHjH6gY9EIhhlDg35WI3nr6J4f0An8IXW31yr9WWA3kEva0m4t30wZGGuLKVgBGKrHX W/z0z8iwEOpcl6rgdLcMNC0F18tiBOh4ZEbRL7vTSJBJLBi+eEdaQUWp73lyHzhPtq8a 8cWHoQ4yy4E5JyvtXK0sLjCrfnKY1jtZYETzY+CyHitDb8EbmCM6wm9SwgjW3TcdPbLR kUUHzv5RuRFSL5YeclJefDad/sROj/GbZlBz8YVzkqDcN62ldFIo2SyOsRTGvfMEwi0L Hf/w== 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=dtahHsPKC+YdLGT5urxGPWdq54nguMZa5qk5YqYOSfQ=; b=Y98TboHIpq3Gw3SQhlVq14GrKgIKFCURGEmqykOJVdtowviiPrwXeZ7Ao4feFh/wg7 LC/O/+N8LZ2Vj9fG8daOy1hlfkaSPzBEF/gDsJ1Ctl1cygxTJSMRmnbG+s0zVjfh6Mtf R+htQfQwoBNIc8Go58ARafxu8ArkGFpus1fbQe/xXIOR+KKo3PUSKVJdNM3r0fQg462G KtCqfq9rAzk+Vh3wsklXFnHjgNPk0Gq9NqaUoO/Am+tWakHJN3GRkE+q5eJhC+o7Dv0E hSNI3R+I+GUZgTgWdBGy8km2M7qMDbvYDFdubT5YGwuKqUXadUjGy+h/gWIx51B64dAG Cynw== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=ekvpdkLQ; 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=ekvpdkLQ; 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 4.4 49/56] atm: zatm: Fix potential Spectre v1 Date: Mon, 14 May 2018 08:48:54 +0200 Message-Id: <20180514064759.341729745@linuxfoundation.org> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180514064754.853201981@linuxfoundation.org> References: <20180514064754.853201981@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?1600421383113753187?= X-GMAIL-MSGID: =?utf-8?q?1600421383113753187?= 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: Gustavo A. R. Silva commit 2be147f7459db5bbf292e0a6f135037b55e20b39 upstream. pool can be indirectly 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: drivers/atm/zatm.c:1462 zatm_ioctl() warn: potential spectre issue 'zatm_dev->pool_info' (local cap) Fix this by sanitizing pool before using it to index zatm_dev->pool_info 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 --- drivers/atm/zatm.c | 3 +++ 1 file changed, 3 insertions(+) --- a/drivers/atm/zatm.c +++ b/drivers/atm/zatm.c @@ -23,6 +23,7 @@ #include #include #include +#include #include #include #include @@ -1456,6 +1457,8 @@ static int zatm_ioctl(struct atm_dev *de return -EFAULT; if (pool < 0 || pool > ZATM_LAST_POOL) return -EINVAL; + pool = array_index_nospec(pool, + ZATM_LAST_POOL + 1); spin_lock_irqsave(&zatm_dev->lock, flags); info = zatm_dev->pool_info[pool]; if (cmd == ZATM_GETPOOLZ) {