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| author | WANG Cong <xiyou.wangcong@gmail.com> | 2017-06-22 00:34:58 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-07-21 08:42:17 +0300 |
| commit | 0526ff300304882d57712e29bb47634dc1110b20 (patch) | |
| tree | 020d0964b8a5606bdb3b73fd931bd09301e082aa | |
| parent | 3f7e07c37ade390391a336e1f2e4c4d5a073c4a8 (diff) | |
| download | linux-0526ff300304882d57712e29bb47634dc1110b20.tar.xz | |
ipv6: avoid unregistering inet6_dev for loopback
commit 60abc0be96e00ca71bac083215ac91ad2e575096 upstream.
The per netns loopback_dev->ip6_ptr is unregistered and set to
NULL when its mtu is set to smaller than IPV6_MIN_MTU, this
leads to that we could set rt->rt6i_idev NULL after a
rt6_uncached_list_flush_dev() and then crash after another
call.
In this case we should just bring its inet6_dev down, rather
than unregistering it, at least prior to commit 176c39af29bc
("netns: fix addrconf_ifdown kernel panic") we always
override the case for loopback.
Thanks a lot to Andrey for finding a reliable reproducer.
Fixes: 176c39af29bc ("netns: fix addrconf_ifdown kernel panic")
Reported-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Daniel Lezcano <dlezcano@fr.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: David Ahern <dsahern@gmail.com>
Tested-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | net/ipv6/addrconf.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index b6f4c42cc8ce..4399beba7f17 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -3316,6 +3316,7 @@ static int addrconf_notify(struct notifier_block *this, unsigned long event, struct net_device *dev = netdev_notifier_info_to_dev(ptr); struct netdev_notifier_changeupper_info *info; struct inet6_dev *idev = __in6_dev_get(dev); + struct net *net = dev_net(dev); int run_pending = 0; int err; @@ -3331,7 +3332,7 @@ static int addrconf_notify(struct notifier_block *this, unsigned long event, case NETDEV_CHANGEMTU: /* if MTU under IPV6_MIN_MTU stop IPv6 on this interface. */ if (dev->mtu < IPV6_MIN_MTU) { - addrconf_ifdown(dev, 1); + addrconf_ifdown(dev, dev != net->loopback_dev); break; } @@ -3447,7 +3448,7 @@ static int addrconf_notify(struct notifier_block *this, unsigned long event, * IPV6_MIN_MTU stop IPv6 on this interface. */ if (dev->mtu < IPV6_MIN_MTU) - addrconf_ifdown(dev, 1); + addrconf_ifdown(dev, dev != net->loopback_dev); } break; |