| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.9 01/78] bonding: fix a potential double-unregister | Date | Tue, 1 Sep 2020 17:09:37 +0200 |
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From: Cong Wang <xiyou.wangcong@gmail.com>
[ Upstream commit 832707021666411d04795c564a4adea5d6b94f17 ]
When we tear down a network namespace, we unregister all the netdevices within it. So we may queue a slave device and a bonding device together in the same unregister queue.
If the only slave device is non-ethernet, it would automatically unregister the bonding device as well. Thus, we may end up unregistering the bonding device twice.
Workaround this special case by checking reg_state.
Fixes: 9b5e383c11b0 ("net: Introduce unregister_netdevice_many()") Reported-by: syzbot+af23e7f3e0a7e10c8b67@syzkaller.appspotmail.com Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Andy Gospodarek <andy@greyhouse.net> Cc: Jay Vosburgh <j.vosburgh@gmail.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- drivers/net/bonding/bond_main.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c @@ -1985,7 +1985,8 @@ static int bond_release_and_destroy(str int ret; ret = bond_release(bond_dev, slave_dev); - if (ret == 0 && !bond_has_slaves(bond)) { + if (ret == 0 && !bond_has_slaves(bond) && + bond_dev->reg_state != NETREG_UNREGISTERING) { bond_dev->priv_flags |= IFF_DISABLE_NETPOLL; netdev_info(bond_dev, "Destroying bond %s\n", bond_dev->name);
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