From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AIpwx4+6uu8t+66YBPUNRROQuBO8CllQA5zRzj/s5uSaw79c7aLCXx1OiqwQwm6ndtfAJvqFuoo9 ARC-Seal: i=1; a=rsa-sha256; t=1523399537; cv=none; d=google.com; s=arc-20160816; b=N3xCYYpNl2hmS6foV+YgPJMsrVltpXPzIF1gWHux9vQh6k9bjuMeEpszzdS4YrQ1b0 bxe8MUdY/jagdcuG9UPAoy8YGcG4yqEEPCgiZU72L68wh0xHsDxsrwtP3Q+RA4/+hJst 9xcBk9C+d67ivkSPFScJTAzfA79KSaNrKvSs6WOSs3qp06RX/8/zXJxJjHTMBYE+Tsxa AARe5IocyhxNiQqY+jF2rudXrELKNJoBZf9En2LEXI1EpcuSWBxWdjB0hsWLgqDi4qPz I2Z91HxWrW3ZAk+NfPq4lKffn/UMiq9xJrs5CNykvrjlDC7NscjQNgkG3fMTXa/Qf1so D7VQ== 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=/fhpy9yGYdr3Ed7r3ImGixy/2W+ZQJo9S7MAX8bww+A=; b=OU59a/ukFbMC7KK7Bz1LrYXlmZOFx4dGErJEscNfSKb9meST7Fck8arNv7GgbPfTje sWcO0ElCrGc6Z+9OJTI7Phu0/etW6UN+zXWoRwj2QCTu1H7yf83jpDOMTI0eShG/s3l3 IczzOzpg8Fxof+fyRbWPf3OaKkxXbIVkn1jYJcZ4El7+l21aC+rKgD4W1z+WqMQF2n96 5nFppgENXgiqNEq5xj4iR+m7FL/hVTap/FjxwQnSU2ABXMrNfZxOzxIYmIBwA3ucjZGI 9SB+j/vySFDNWXHA+wveHkCTWXMJNRFET3u5P7owAlTN3rgu8uhULZSngGFUBSef3DBW 7ZAA== 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, Eric Dumazet , syzbot , "David S. Miller" Subject: [PATCH 4.15 144/168] ip_tunnel: better validate user provided tunnel names Date: Wed, 11 Apr 2018 00:24:46 +0200 Message-Id: <20180410212807.213818388@linuxfoundation.org> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180410212800.144079021@linuxfoundation.org> References: <20180410212800.144079021@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?1597399721558398596?= X-GMAIL-MSGID: =?utf-8?q?1597400193229069803?= 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: Eric Dumazet [ Upstream commit 9cb726a212a82c88c98aa9f0037fd04777cd8fe5 ] Use dev_valid_name() to make sure user does not provide illegal device name. syzbot caught the following bug : BUG: KASAN: stack-out-of-bounds in strlcpy include/linux/string.h:300 [inline] BUG: KASAN: stack-out-of-bounds in __ip_tunnel_create+0xca/0x6b0 net/ipv4/ip_tunnel.c:257 Write of size 20 at addr ffff8801ac79f810 by task syzkaller268107/4482 CPU: 0 PID: 4482 Comm: syzkaller268107 Not tainted 4.16.0+ #1 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b9/0x29f lib/dump_stack.c:53 print_address_description+0x6c/0x20b mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.7+0xac/0x2f5 mm/kasan/report.c:412 check_memory_region_inline mm/kasan/kasan.c:260 [inline] check_memory_region+0x13e/0x1b0 mm/kasan/kasan.c:267 memcpy+0x37/0x50 mm/kasan/kasan.c:303 strlcpy include/linux/string.h:300 [inline] __ip_tunnel_create+0xca/0x6b0 net/ipv4/ip_tunnel.c:257 ip_tunnel_create net/ipv4/ip_tunnel.c:352 [inline] ip_tunnel_ioctl+0x818/0xd40 net/ipv4/ip_tunnel.c:861 ipip_tunnel_ioctl+0x1c5/0x420 net/ipv4/ipip.c:350 dev_ifsioc+0x43e/0xb90 net/core/dev_ioctl.c:334 dev_ioctl+0x69a/0xcc0 net/core/dev_ioctl.c:525 sock_ioctl+0x47e/0x680 net/socket.c:1015 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x1cf/0x1650 fs/ioctl.c:684 ksys_ioctl+0xa9/0xd0 fs/ioctl.c:701 SYSC_ioctl fs/ioctl.c:708 [inline] SyS_ioctl+0x24/0x30 fs/ioctl.c:706 do_syscall_64+0x29e/0x9d0 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 Fixes: c54419321455 ("GRE: Refactor GRE tunneling code.") Signed-off-by: Eric Dumazet Reported-by: syzbot Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv4/ip_tunnel.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) --- a/net/ipv4/ip_tunnel.c +++ b/net/ipv4/ip_tunnel.c @@ -253,13 +253,14 @@ static struct net_device *__ip_tunnel_cr struct net_device *dev; char name[IFNAMSIZ]; - if (parms->name[0]) + err = -E2BIG; + if (parms->name[0]) { + if (!dev_valid_name(parms->name)) + goto failed; strlcpy(name, parms->name, IFNAMSIZ); - else { - if (strlen(ops->kind) > (IFNAMSIZ - 3)) { - err = -E2BIG; + } else { + if (strlen(ops->kind) > (IFNAMSIZ - 3)) goto failed; - } strlcpy(name, ops->kind, IFNAMSIZ); strncat(name, "%d", 2); }