diff options
| author |   Jason Wang <jasowang@redhat.com> | 2017-12-08 12:02:30 +0800 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2017-12-08 10:44:27 -0500 |
| commit | 124da8f6118bce3d9aeb5c6f5395ed131141aad5 (patch) | |
| tree | 283a91e5edd6c77ff244976cb1d3d479b664cc26 /drivers/net/tun.c | |
| parent | Merge branch 'smc-fixes-next' (diff) | |
| download | linux-dev-124da8f6118bce3d9aeb5c6f5395ed131141aad5.tar.xz linux-dev-124da8f6118bce3d9aeb5c6f5395ed131141aad5.zip | |
tuntap: fix possible deadlock when fail to register netdev
Private destructor could be called when register_netdev() fail with
rtnl lock held. This will lead deadlock in tun_free_netdev() who tries
to hold rtnl_lock. Fixing this by switching to use spinlock to
synchronize.
Fixes: 96f84061620c ("tun: add eBPF based queue selection method")
Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Willem de Bruijn <willemb@google.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/tun.c')
| -rw-r--r-- | drivers/net/tun.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/drivers/net/tun.c b/drivers/net/tun.c index c2ad8f3858d1..e367d6310353 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -2048,8 +2048,11 @@ static int __tun_set_steering_ebpf(struct tun_struct *tun, new->prog = prog; } - old = rtnl_dereference(tun->steering_prog); + spin_lock_bh(&tun->lock); + old = rcu_dereference_protected(tun->steering_prog, + lockdep_is_held(&tun->lock)); rcu_assign_pointer(tun->steering_prog, new); + spin_unlock_bh(&tun->lock); if (old) call_rcu(&old->rcu, tun_steering_prog_free); @@ -2065,9 +2068,7 @@ static void tun_free_netdev(struct net_device *dev) free_percpu(tun->pcpu_stats); tun_flow_uninit(tun); security_tun_dev_free_security(tun->security); - rtnl_lock(); __tun_set_steering_ebpf(tun, NULL); - rtnl_unlock(); } static void tun_setup(struct net_device *dev) |