kernel/linux.git/drivers/net/tun.c, branch v5.19

net: tun: avoid disabling NAPI twice

2022-06-30T18:34:10+00:00

Eric reports that syzbot made short work out of my speculative fix. Indeed when queue gets detached its tfile->tun remains, so we would try to stop NAPI twice with a detach(), close() sequence. Alternative fix would be to move tun_napi_disable() to tun_detach_all() and let the NAPI run after the queue has been detached. Fixes: a8fc8cb5692a ("net: tun: stop NAPI when detaching queues") Reported-by: syzbot Reported-by: Eric Dumazet Reviewed-by: Eric Dumazet Link: https://lore.kernel.org/r/20220629181911.372047-1-kuba@kernel.org Signed-off-by: Jakub Kicinski

net: tun: stop NAPI when detaching queues

2022-06-28T04:48:01+00:00

While looking at a syzbot report I noticed the NAPI only gets disabled before it's deleted. I think that user can detach the queue before destroying the device and the NAPI will never be stopped. Fixes: 943170998b20 ("tun: enable NAPI for TUN/TAP driver") Acked-by: Petar Penkov Link: https://lore.kernel.org/r/20220623042105.2274812-1-kuba@kernel.org Signed-off-by: Jakub Kicinski

net: tun: unlink NAPI from device on destruction

2022-06-24T23:28:08+00:00

Syzbot found a race between tun file and device destruction. NAPIs live in struct tun_file which can get destroyed before the netdev so we have to del them explicitly. The current code is missing deleting the NAPI if the queue was detached first. Fixes: 943170998b20 ("tun: enable NAPI for TUN/TAP driver") Reported-by: syzbot+b75c138e9286ac742647@syzkaller.appspotmail.com Link: https://lore.kernel.org/r/20220623042039.2274708-1-kuba@kernel.org Signed-off-by: Jakub Kicinski

net: switch to netif_napi_add_tx()

2022-05-05T22:54:12+00:00

Switch net callers to the new API not requiring the NAPI_POLL_WEIGHT argument. Acked-by: Florian Fainelli Reviewed-by: Alex Elder Acked-by: Mat Martineau Acked-by: Alexandra Winter Link: https://lore.kernel.org/r/20220504163725.550782-1-kuba@kernel.org Signed-off-by: Jakub Kicinski

tun: annotate access to queue->trans_start

2022-04-14T06:30:09+00:00

Commit 5337824f4dc4 ("net: annotate accesses to queue->trans_start") introduced a new helper, txq_trans_cond_update, to update queue->trans_start using WRITE_ONCE. One snippet in drivers/net/tun.c was missed, as it was introduced roughly at the same time. Fixes: 5337824f4dc4 ("net: annotate accesses to queue->trans_start") Cc: Eric Dumazet Signed-off-by: Antoine Tenart Reviewed-by: Eric Dumazet Link: https://lore.kernel.org/r/20220412135852.466386-1-atenart@kernel.org Signed-off-by: Paolo Abeni

net: add per-cpu storage and net->core_stats

2022-03-12T07:17:24+00:00

Before adding yet another possibly contended atomic_long_t, it is time to add per-cpu storage for existing ones: dev->tx_dropped, dev->rx_dropped, and dev->rx_nohandler Because many devices do not have to increment such counters, allocate the per-cpu storage on demand, so that dev_get_stats() does not have to spend considerable time folding zero counters. Note that some drivers have abused these counters which were supposed to be only used by core networking stack. v4: should use per_cpu_ptr() in dev_get_stats() (Jakub) v3: added a READ_ONCE() in netdev_core_stats_alloc() (Paolo) v2: add a missing include (reported by kernel test robot ) Change in netdev_core_stats_alloc() (Jakub) Signed-off-by: Eric Dumazet Cc: jeffreyji Reviewed-by: Brian Vazquez Reviewed-by: Jakub Kicinski Acked-by: Paolo Abeni Link: https://lore.kernel.org/r/20220311051420.2608812-1-eric.dumazet@gmail.com Signed-off-by: Jakub Kicinski

tun: vxlan: Use netif_rx().

2022-03-07T11:40:40+00:00

Since commit baebdf48c3600 ("net: dev: Makes sure netif_rx() can be invoked in any context.") the function netif_rx() can be used in preemptible/thread context as well as in interrupt context. Use netif_rx(). Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: David S. Miller

net: tun: track dropped skb via kfree_skb_reason()

2022-03-06T11:04:01+00:00

The TUN can be used as vhost-net backend. E.g, the tun_net_xmit() is the interface to forward the skb from TUN to vhost-net/virtio-net. However, there are many "goto drop" in the TUN driver. Therefore, the kfree_skb_reason() is involved at each "goto drop" to help userspace ftrace/ebpf to track the reason for the loss of packets. The below reasons are introduced: - SKB_DROP_REASON_DEV_READY - SKB_DROP_REASON_NOMEM - SKB_DROP_REASON_HDR_TRUNC - SKB_DROP_REASON_TAP_FILTER - SKB_DROP_REASON_TAP_TXFILTER Cc: Joao Martins Cc: Joe Jin Signed-off-by: Dongli Zhang Signed-off-by: David S. Miller

net: tun: split run_ebpf_filter() and pskb_trim() into different "if statement"

2022-03-06T11:04:01+00:00

No functional change. Just to split the if statement into different conditions to use kfree_skb_reason() to trace the reason later. Cc: Joao Martins Cc: Joe Jin Signed-off-by: Dongli Zhang Reviewed-by: David Ahern Signed-off-by: David S. Miller

tuntap: add sanity checks about msg_controllen in sendmsg

2022-03-03T06:00:59+00:00

In patch [1], tun_msg_ctl was added to allow pass batched xdp buffers to tun_sendmsg. Although we donot use msg_controllen in this path, we should check msg_controllen to make sure the caller pass a valid msg_ctl. [1]: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=fe8dd45bb7556246c6b76277b1ba4296c91c2505 Reported-by: Eric Dumazet Suggested-by: Jason Wang Signed-off-by: Harold Huang Acked-by: Jason Wang Link: https://lore.kernel.org/r/20220303022441.383865-1-baymaxhuang@gmail.com Signed-off-by: Jakub Kicinski