netdev - Re: [PATCH net] ip6_tunnel: do not allow loading ip6

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Date:   Mon, 18 Sep 2017 16:35:14 -0700 (PDT)
From:   David Miller <davem@...emloft.net>
To:     lucien.xin@...il.com
Cc:     netdev@...r.kernel.org, xeb@...l.ru, jbenc@...hat.com
Subject: Re: [PATCH net] ip6_tunnel: do not allow loading ip6_tunnel if
 ipv6 is disabled in cmdline

From: Xin Long <lucien.xin@...il.com>
Date: Fri, 15 Sep 2017 15:58:33 +0800

> If ipv6 has been disabled from cmdline since kernel started, it makes
> no sense to allow users to create any ip6 tunnel. Otherwise, it could
> some potential problem.
> 
> Jianlin found a kernel crash caused by this in ip6_gre when he set
> ipv6.disable=1 in grub:
> 
> [  209.588865] Unable to handle kernel paging request for data at address 0x00000080
> [  209.588872] Faulting instruction address: 0xc000000000a3aa6c
> [  209.588879] Oops: Kernel access of bad area, sig: 11 [#1]
> [  209.589062] NIP [c000000000a3aa6c] fib_rules_lookup+0x4c/0x260
> [  209.589071] LR [c000000000b9ad90] fib6_rule_lookup+0x50/0xb0
> [  209.589076] Call Trace:
> [  209.589097] fib6_rule_lookup+0x50/0xb0
> [  209.589106] rt6_lookup+0xc4/0x110
> [  209.589116] ip6gre_tnl_link_config+0x214/0x2f0 [ip6_gre]
> [  209.589125] ip6gre_newlink+0x138/0x3a0 [ip6_gre]
> [  209.589134] rtnl_newlink+0x798/0xb80
> [  209.589142] rtnetlink_rcv_msg+0xec/0x390
> [  209.589151] netlink_rcv_skb+0x138/0x150
> [  209.589159] rtnetlink_rcv+0x48/0x70
> [  209.589169] netlink_unicast+0x538/0x640
> [  209.589175] netlink_sendmsg+0x40c/0x480
> [  209.589184] ___sys_sendmsg+0x384/0x4e0
> [  209.589194] SyS_sendmsg+0xd4/0x140
> [  209.589201] SyS_socketcall+0x3e0/0x4f0
> [  209.589209] system_call+0x38/0xe0
> 
> This patch is to return -EOPNOTSUPP in ip6_tunnel_init if ipv6 has been
> disabled from cmdline.
> 
> Reported-by: Jianlin Shi <jishi@...hat.com>
> Signed-off-by: Xin Long <lucien.xin@...il.com>

Applied and queued up for -stable, thanks.