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| author | WANG Cong <xiyou.wangcong@gmail.com> | 2017-06-21 14:34:58 -0700 |
|---|---|---|
| committer | Willy Tarreau <w@1wt.eu> | 2017-11-02 07:16:30 +0100 |
| commit | fa69abfe6a07ae3c009b30271966b871799077b6 (patch) | |
| tree | 742c64e83a3f3e2a80667e7ac0aa8a2040932120 | |
| parent | 98b9e94ba66c9907ff8f7276c6f9bb71cce1c4ae (diff) | |
| download | linux-fa69abfe6a07ae3c009b30271966b871799077b6.tar.gz linux-fa69abfe6a07ae3c009b30271966b871799077b6.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>
Signed-off-by: Willy Tarreau <w@1wt.eu>
| -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 9c4aa2e22448..5ea5f77c0ec1 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -2892,6 +2892,7 @@ static int addrconf_notify(struct notifier_block *this, unsigned long event, { struct net_device *dev = (struct net_device *) data; struct inet6_dev *idev = __in6_dev_get(dev); + struct net *net = dev_net(dev); int run_pending = 0; int err; @@ -2988,7 +2989,7 @@ 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; |