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| author | WANG Cong <xiyou.wangcong@gmail.com> | 2017-06-21 14:34:58 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-07-21 08:12:21 +0200 |
| commit | e88fa5f09b1f98c3e907937415d0038ba9af3044 (patch) | |
| tree | a48d2b686ff7fa6b27aba8dbc6c67d2db8002c83 | |
| parent | 4d29e8c0e9319ce9d391c57d3133306c05b6cef5 (diff) | |
| download | linux-e88fa5f09b1f98c3e907937415d0038ba9af3044.tar.gz linux-e88fa5f09b1f98c3e907937415d0038ba9af3044.tar.bz2 linux-e88fa5f09b1f98c3e907937415d0038ba9af3044.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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | net/ipv6/addrconf.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index f7d8c34bd609..aec79884817c 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -2829,6 +2829,7 @@ 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; @@ -2925,7 +2926,7 @@ 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; |