kernel/drivers/net/tun.c, branch linux-5.1.y

tun: wake up waitqueues after IFF_UP is set

2019-07-03T11:13:42Z

[ Upstream commit 72b319dc08b4924a29f5e2560ef6d966fa54c429 ] Currently after setting tap0 link up, the tun code wakes tx/rx waited queues up in tun_net_open() when .ndo_open() is called, however the IFF_UP flag has not been set yet. If there's already a wait queue, it would fail to transmit when checking the IFF_UP flag in tun_sendmsg(). Then the saving vhost_poll_start() will add the wq into wqh until it is waken up again. Although this works when IFF_UP flag has been set when tun_chr_poll detects; this is not true if IFF_UP flag has not been set at that time. Sadly the latter case is a fatal error, as the wq will never be waken up in future unless later manually setting link up on purpose. Fix this by moving the wakeup process into the NETDEV_UP event notifying process, this makes sure IFF_UP has been set before all waited queues been waken up. Signed-off-by: Fei Li Acked-by: Jason Wang Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

tuntap: synchronize through tfiles array instead of tun->numqueues

2019-05-16T17:35:38Z

[ Upstream commit 9871a9e47a2646fe30ae7fd2e67668a8d30912f6 ] When a queue(tfile) is detached through __tun_detach(), we move the last enabled tfile to the position where detached one sit but don't NULL out last position. We expect to synchronize the datapath through tun->numqueues. Unfortunately, this won't work since we're lacking sufficient mechanism to order or synchronize the access to tun->numqueues. To fix this, NULL out the last position during detaching and check RCU protected tfile against NULL instead of checking tun->numqueues in datapath. Cc: YueHaibing Cc: Cong Wang Cc: weiyongjun (A) Cc: Eric Dumazet Fixes: c8d68e6be1c3b ("tuntap: multiqueue support") Signed-off-by: Jason Wang Reviewed-by: Wei Yongjun Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

tuntap: fix dividing by zero in ebpf queue selection

2019-05-16T17:35:37Z

[ Upstream commit a35d310f03a692bf4798eb309a1950a06a150620 ] We need check if tun->numqueues is zero (e.g for the persist device) before trying to use it for modular arithmetic. Reported-by: Eric Dumazet Fixes: 96f84061620c6("tun: add eBPF based queue selection method") Signed-off-by: Jason Wang Reviewed-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

tun: add a missing rcu_read_unlock() in error path

2019-03-16T20:16:37Z

In my latest patch I missed one rcu_read_unlock(), in case device is down. Fixes: 4477138fa0ae ("tun: properly test for IFF_UP") Signed-off-by: Eric Dumazet Reported-by: syzbot Signed-off-by: David S. Miller

tun: properly test for IFF_UP

2019-03-15T22:42:11Z

Same reasons than the ones explained in commit 4179cb5a4c92 ("vxlan: test dev->flags & IFF_UP before calling netif_rx()") netif_rx_ni() or napi_gro_frags() must be called under a strict contract. At device dismantle phase, core networking clears IFF_UP and flush_all_backlogs() is called after rcu grace period to make sure no incoming packet might be in a cpu backlog and still referencing the device. A similar protocol is used for gro layer. Most drivers call netif_rx() from their interrupt handler, and since the interrupts are disabled at device dismantle, netif_rx() does not have to check dev->flags & IFF_UP Virtual drivers do not have this guarantee, and must therefore make the check themselves. Fixes: 1bd4978a88ac ("tun: honor IFF_UP in tun_get_user()") Signed-off-by: Eric Dumazet Reported-by: syzbot Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2019-03-02T20:54:35Z

tun: remove unnecessary memory barrier

2019-02-25T22:27:21Z

Replace set_current_state with __set_current_state since no memory barrier is needed at this point. Signed-off-by: Timur Celik Reviewed-by: Eric Dumazet Signed-off-by: David S. Miller

tun: fix blocking read

2019-02-25T06:11:53Z

This patch moves setting of the current state into the loop. Otherwise the task may end up in a busy wait loop if none of the break conditions are met. Signed-off-by: Timur Celik Signed-off-by: David S. Miller

net: Don't set transport offset to invalid value

2019-02-22T20:55:31Z

If the socket was created with socket(AF_PACKET, SOCK_RAW, 0), skb->protocol will be unset, __skb_flow_dissect() will fail, and skb_probe_transport_header() will fall back to the offset_hint, making the resulting skb_transport_offset incorrect. If, however, there is no transport header in the packet, transport_header shouldn't be set to an arbitrary value. Fix it by leaving the transport offset unset if it couldn't be found, to be explicit rather than to fill it with some wrong value. It changes the behavior, but if some code relied on the old behavior, it would be broken anyway, as the old one is incorrect. Signed-off-by: Maxim Mikityanskiy Signed-off-by: David S. Miller

tun: move the call to tun_set_real_num_queues

2019-01-31T05:40:25Z

Call tun_set_real_num_queues() after the increment of tun->numqueues since the former depends on it. Otherwise, the number of queues is not correctly accounted for, which results to warnings similar to: "vnet0 selects TX queue 11, but real number of TX queues is 11". Fixes: 0b7959b62573 ("tun: publish tfile after it's fully initialized") Reported-and-tested-by: George Amanakis Signed-off-by: George Amanakis Signed-off-by: Stanislav Fomichev Signed-off-by: David S. Miller