kernel/linux.git/net/core/dev.c, branch linux-4.20.y

net: Fix for_each_netdev_feature on Big endian

2019-02-23T08:08:05+00:00

[ Upstream commit 3b89ea9c5902acccdbbdec307c85edd1bf52515e ] The features attribute is of type u64 and stored in the native endianes on the system. The for_each_set_bit() macro takes a pointer to a 32 bit array and goes over the bits in this area. On little Endian systems this also works with an u64 as the most significant bit is on the highest address, but on big endian the words are swapped. When we expect bit 15 here we get bit 47 (15 + 32). This patch converts it more or less to its own for_each_set_bit() implementation which works on 64 bit integers directly. This is then completely in host endianness and should work like expected. Fixes: fd867d51f ("net/core: generic support for disabling netdev features down stack") Signed-off-by: Hauke Mehrtens Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

net: set default network namespace in init_dummy_netdev()

2019-02-06T16:27:36+00:00

[ Upstream commit 35edfdc77f683c8fd27d7732af06cf6489af60a5 ] Assign a default net namespace to netdevs created by init_dummy_netdev(). Fixes a NULL pointer dereference caused by busy-polling a socket bound to an iwlwifi wireless device, which bumps the per-net BUSYPOLLRXPACKETS stat if napi_poll() received packets: BUG: unable to handle kernel NULL pointer dereference at 0000000000000190 IP: napi_busy_loop+0xd6/0x200 Call Trace: sock_poll+0x5e/0x80 do_sys_poll+0x324/0x5a0 SyS_poll+0x6c/0xf0 do_syscall_64+0x6b/0x1f0 entry_SYSCALL_64_after_hwframe+0x3d/0xa2 Fixes: 7db6b048da3b ("net: Commonize busy polling code to focus on napi_id instead of socket") Signed-off-by: Josh Elsasser Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: use skb_list_del_init() to remove from RX sublists

2018-12-06T00:22:05+00:00

list_del() leaves the skb->next pointer poisoned, which can then lead to a crash in e.g. OVS forwarding. For example, setting up an OVS VXLAN forwarding bridge on sfc as per: ======== $ ovs-vsctl show 5dfd9c47-f04b-4aaa-aa96-4fbb0a522a30 Bridge "br0" Port "br0" Interface "br0" type: internal Port "enp6s0f0" Interface "enp6s0f0" Port "vxlan0" Interface "vxlan0" type: vxlan options: {key="1", local_ip="10.0.0.5", remote_ip="10.0.0.4"} ovs_version: "2.5.0" ======== (where 10.0.0.5 is an address on enp6s0f1) and sending traffic across it will lead to the following panic: ======== general protection fault: 0000 [#1] SMP PTI CPU: 5 PID: 0 Comm: swapper/5 Not tainted 4.20.0-rc3-ehc+ #701 Hardware name: Dell Inc. PowerEdge R710/0M233H, BIOS 6.4.0 07/23/2013 RIP: 0010:dev_hard_start_xmit+0x38/0x200 Code: 53 48 89 fb 48 83 ec 20 48 85 ff 48 89 54 24 08 48 89 4c 24 18 0f 84 ab 01 00 00 48 8d 86 90 00 00 00 48 89 f5 48 89 44 24 10 <4c> 8b 33 48 c7 03 00 00 00 00 48 8b 05 c7 d1 b3 00 4d 85 f6 0f 95 RSP: 0018:ffff888627b437e0 EFLAGS: 00010202 RAX: 0000000000000000 RBX: dead000000000100 RCX: ffff88862279c000 RDX: ffff888614a342c0 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff888618a88000 R08: 0000000000000001 R09: 00000000000003e8 R10: 0000000000000000 R11: ffff888614a34140 R12: 0000000000000000 R13: 0000000000000062 R14: dead000000000100 R15: ffff888616430000 FS: 0000000000000000(0000) GS:ffff888627b40000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f6d2bc6d000 CR3: 000000000200a000 CR4: 00000000000006e0 Call Trace: __dev_queue_xmit+0x623/0x870 ? masked_flow_lookup+0xf7/0x220 [openvswitch] ? ep_poll_callback+0x101/0x310 do_execute_actions+0xaba/0xaf0 [openvswitch] ? __wake_up_common+0x8a/0x150 ? __wake_up_common_lock+0x87/0xc0 ? queue_userspace_packet+0x31c/0x5b0 [openvswitch] ovs_execute_actions+0x47/0x120 [openvswitch] ovs_dp_process_packet+0x7d/0x110 [openvswitch] ovs_vport_receive+0x6e/0xd0 [openvswitch] ? dst_alloc+0x64/0x90 ? rt_dst_alloc+0x50/0xd0 ? ip_route_input_slow+0x19a/0x9a0 ? __udp_enqueue_schedule_skb+0x198/0x1b0 ? __udp4_lib_rcv+0x856/0xa30 ? __udp4_lib_rcv+0x856/0xa30 ? cpumask_next_and+0x19/0x20 ? find_busiest_group+0x12d/0xcd0 netdev_frame_hook+0xce/0x150 [openvswitch] __netif_receive_skb_core+0x205/0xae0 __netif_receive_skb_list_core+0x11e/0x220 netif_receive_skb_list+0x203/0x460 ? __efx_rx_packet+0x335/0x5e0 [sfc] efx_poll+0x182/0x320 [sfc] net_rx_action+0x294/0x3c0 __do_softirq+0xca/0x297 irq_exit+0xa6/0xb0 do_IRQ+0x54/0xd0 common_interrupt+0xf/0xf ======== So, in all listified-receive handling, instead pull skbs off the lists with skb_list_del_init(). Fixes: 9af86f933894 ("net: core: fix use-after-free in __netif_receive_skb_list_core") Fixes: 7da517a3bc52 ("net: core: Another step of skb receive list processing") Fixes: a4ca8b7df73c ("net: ipv4: fix drop handling in ip_list_rcv() and ip_list_rcv_finish()") Fixes: d8269e2cbf90 ("net: ipv6: listify ipv6_rcv() and ip6_rcv_finish()") Signed-off-by: Edward Cree Signed-off-by: David S. Miller

net/core: tidy up an error message

2018-12-04T00:14:51+00:00

netif_napi_add() could report an error like this below due to it allows to pass a format string for wildcarding before calling dev_get_valid_name(), "netif_napi_add() called with weight 256 on device eth%d" For example, hns_enet_drv module does this. hns_nic_try_get_ae hns_nic_init_ring_data netif_napi_add register_netdev dev_get_valid_name Hence, make it a bit more human-readable by using netdev_err_once() instead. Signed-off-by: Qian Cai Signed-off-by: David S. Miller

net: fix XPS static_key accounting

2018-11-29T19:06:08+00:00

Commit 04157469b7b8 ("net: Use static_key for XPS maps") introduced a static key for XPS, but the increments/decrements don't match. First, the static key's counter is incremented once for each queue, but only decremented once for a whole batch of queues, leading to large unbalances. Second, the xps_rxqs_needed key is decremented whenever we reset a batch of queues, whether they had any rxqs mapping or not, so that if we setup cpu-XPS on em1 and RXQS-XPS on em2, resetting the queues on em1 would decrement the xps_rxqs_needed key. This reworks the accounting scheme so that the xps_needed key is incremented only once for each type of XPS for all the queues on a device, and the xps_rxqs_needed key is incremented only once for all queues. This is sufficient to let us retrieve queues via get_xps_queue(). This patch introduces a new reset_xps_maps(), which reinitializes and frees the appropriate map (xps_rxqs_map or xps_cpus_map), and drops a reference to the needed keys: - both xps_needed and xps_rxqs_needed, in case of rxqs maps, - only xps_needed, in case of CPU maps. Now, we also need to call reset_xps_maps() at the end of __netif_set_xps_queue() when there's no active map left, for example when writing '00000000,00000000' to all queues' xps_rxqs setting. Fixes: 04157469b7b8 ("net: Use static_key for XPS maps") Signed-off-by: Sabrina Dubroca Signed-off-by: David S. Miller

net: restore call to netdev_queue_numa_node_write when resetting XPS

2018-11-29T19:06:08+00:00

Before commit 80d19669ecd3 ("net: Refactor XPS for CPUs and Rx queues"), netif_reset_xps_queues() did netdev_queue_numa_node_write() for all the queues being reset. Now, this is only done when the "active" variable in clean_xps_maps() is false, ie when on all the CPUs, there's no active XPS mapping left. Fixes: 80d19669ecd3 ("net: Refactor XPS for CPUs and Rx queues") Signed-off-by: Sabrina Dubroca Signed-off-by: David S. Miller

net: don't keep lonely packets forever in the gro hash

2018-11-23T19:18:53+00:00

Eric noted that with UDP GRO and NAPI timeout, we could keep a single UDP packet inside the GRO hash forever, if the related NAPI instance calls napi_gro_complete() at an higher frequency than the NAPI timeout. Willem noted that even TCP packets could be trapped there, till the next retransmission. This patch tries to address the issue, flushing the old packets - those with a NAPI_GRO_CB age before the current jiffy - before scheduling the NAPI timeout. The rationale is that such a timeout should be well below a jiffy and we are not flushing packets eligible for sane GRO. v1 -> v2: - clarified the commit message and comment RFC -> v1: - added 'Fixes tags', cleaned-up the wording. Reported-by: Eric Dumazet Fixes: 3b47d30396ba ("net: gro: add a per device gro flush timer") Signed-off-by: Paolo Abeni Acked-by: Willem de Bruijn Acked-by: Eric Dumazet Signed-off-by: David S. Miller

net-gro: reset skb->pkt_type in napi_reuse_skb()

2018-11-18T05:59:18+00:00

eth_type_trans() assumes initial value for skb->pkt_type is PACKET_HOST. This is indeed the value right after a fresh skb allocation. However, it is possible that GRO merged a packet with a different value (like PACKET_OTHERHOST in case macvlan is used), so we need to make sure napi->skb will have pkt_type set back to PACKET_HOST. Otherwise, valid packets might be dropped by the stack because their pkt_type is not PACKET_HOST. napi_reuse_skb() was added in commit 96e93eab2033 ("gro: Add internal interfaces for VLAN"), but this bug always has been there. Fixes: 96e93eab2033 ("gro: Add internal interfaces for VLAN") Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

net: do not abort bulk send on BQL status

2018-11-03T22:40:01+00:00

Before calling dev_hard_start_xmit(), upper layers tried to cook optimal skb list based on BQL budget. Problem is that GSO packets can end up comsuming more than the BQL budget. Breaking the loop is not useful, since requeued packets are ahead of any packets still in the qdisc. It is also more expensive, since next TX completion will push these packets later, while skbs are not in cpu caches. It is also a behavior difference with TSO packets, that can break the BQL limit by a large amount. Note that drivers should use __netdev_tx_sent_queue() in order to have optimal xmit_more support, and avoid useless atomic operations as shown in the following patch. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

net: Properly unlink GRO packets on overflow.

2018-10-28T17:35:12+00:00

Just like with normal GRO processing, we have to initialize skb->next to NULL when we unlink overflow packets from the GRO hash lists. Fixes: d4546c2509b1 ("net: Convert GRO SKB handling to list_head.") Reported-by: Oleksandr Natalenko Tested-by: Oleksandr Natalenko Signed-off-by: David S. Miller