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| author | WANG Cong <xiyou.wangcong@gmail.com> | 2017-06-21 14:34:58 -0700 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2017-09-15 18:30:14 +0100 |
| commit | b7aba3723145ea05af6ac18ddecc86e74321e33f (patch) | |
| tree | 978141046036642dfb5a8d32c0f7a25c918ba5ca | |
| parent | 295302357e7ebc359e07cf8404e8dad4a51dd674 (diff) | |
| download | linux-b7aba3723145ea05af6ac18ddecc86e74321e33f.tar.gz linux-b7aba3723145ea05af6ac18ddecc86e74321e33f.tar.bz2 linux-b7aba3723145ea05af6ac18ddecc86e74321e33f.zip | |
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>
[bwh: Backported to 3.16: the NETDEV_CHANGEMTU case used to fall-through to the
NETDEV_DOWN case here, so replace that with a separate call to addrconf_ifdown()]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
| -rw-r--r-- | net/ipv6/addrconf.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index 98bc5818ef0c..d5fe33752ca6 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -2823,6 +2823,7 @@ static int addrconf_notify(struct notifier_block *this, unsigned long event, { struct net_device *dev = netdev_notifier_info_to_dev(ptr); struct inet6_dev *idev = __in6_dev_get(dev); + struct net *net = dev_net(dev); int run_pending = 0; int err; @@ -2916,7 +2917,7 @@ 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; @@ -2937,6 +2938,8 @@ static int addrconf_notify(struct notifier_block *this, unsigned long event, * if MTU under IPV6_MIN_MTU. * Stop IPv6 on this interface. */ + addrconf_ifdown(dev, dev != net->loopback_dev); + break; case NETDEV_DOWN: case NETDEV_UNREGISTER: |