kernel/linux.git/net/hsr, branch linux-6.0.y

hsr: Synchronize sequence number updates.

2022-12-31T12:26:08+00:00

[ Upstream commit 5c7aa13210c3abdd34fd421f62347665ec6eb551 ] hsr_register_frame_out() compares new sequence_nr vs the old one recorded in hsr_node::seq_out and if the new sequence_nr is higher then it will be written to hsr_node::seq_out as the new value. This operation isn't locked so it is possible that two frames with the same sequence number arrive (via the two slave devices) and are fed to hsr_register_frame_out() at the same time. Both will pass the check and update the sequence counter later to the same value. As a result the content of the same packet is fed into the stack twice. This was noticed by running ping and observing DUP being reported from time to time. Instead of using the hsr_priv::seqnr_lock for the whole receive path (as it is for sending in the master node) add an additional lock that is only used for sequence number checks and updates. Add a per-node lock that is used during sequence number reads and updates. Fixes: f421436a591d3 ("net/hsr: Add support for the High-availability Seamless Redundancy protocol (HSRv0)") Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

hsr: Synchronize sending frames to have always incremented outgoing seq nr.

2022-12-31T12:26:08+00:00

[ Upstream commit 06afd2c31d338fa762548580c1bf088703dd1e03 ] Sending frames via the hsr (master) device requires a sequence number which is tracked in hsr_priv::sequence_nr and protected by hsr_priv::seqnr_lock. Each time a new frame is sent, it will obtain a new id and then send it via the slave devices. Each time a packet is sent (via hsr_forward_do()) the sequence number is checked via hsr_register_frame_out() to ensure that a frame is not handled twice. This make sense for the receiving side to ensure that the frame is not injected into the stack twice after it has been received from both slave ports. There is no locking to cover the sending path which means the following scenario is possible: CPU0 CPU1 hsr_dev_xmit(skb1) hsr_dev_xmit(skb2) fill_frame_info() fill_frame_info() hsr_fill_frame_info() hsr_fill_frame_info() handle_std_frame() handle_std_frame() skb1's sequence_nr = 1 skb2's sequence_nr = 2 hsr_forward_do() hsr_forward_do() hsr_register_frame_out(, 2) // okay, send) hsr_register_frame_out(, 1) // stop, lower seq duplicate Both skbs (or their struct hsr_frame_info) received an unique id. However since skb2 was sent before skb1, the higher sequence number was recorded in hsr_register_frame_out() and the late arriving skb1 was dropped and never sent. This scenario has been observed in a three node HSR setup, with node1 + node2 having ping and iperf running in parallel. From time to time ping reported a missing packet. Based on tracing that missing ping packet did not leave the system. It might be possible (didn't check) to drop the sequence number check on the sending side. But if the higher sequence number leaves on wire before the lower does and the destination receives them in that order and it will drop the packet with the lower sequence number and never inject into the stack. Therefore it seems the only way is to lock the whole path from obtaining the sequence number and sending via dev_queue_xmit() and assuming the packets leave on wire in the same order (and don't get reordered by the NIC). Cover the whole path for the master interface from obtaining the ID until after it has been forwarded via hsr_forward_skb() to ensure the skbs are sent to the NIC in the order of the assigned sequence numbers. Fixes: f421436a591d3 ("net/hsr: Add support for the High-availability Seamless Redundancy protocol (HSRv0)") Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

hsr: Disable netpoll.

2022-12-31T12:26:08+00:00

[ Upstream commit d5c7652eb16fa203d82546e0285136d7b321ffa9 ] The hsr device is a software device. Its net_device_ops::ndo_start_xmit() routine will process the packet and then pass the resulting skb to dev_queue_xmit(). During processing, hsr acquires a lock with spin_lock_bh() (hsr_add_node()) which needs to be promoted to the _irq() suffix in order to avoid a potential deadlock. Then there are the warnings in dev_queue_xmit() (due to local_bh_disable() with disabled interrupts) left. Instead trying to address those (there is qdisc and…) for netpoll sake, just disable netpoll on hsr. Disable netpoll on hsr and replace the _irqsave() locking with _bh(). Fixes: f421436a591d3 ("net/hsr: Add support for the High-availability Seamless Redundancy protocol (HSRv0)") Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

hsr: Avoid double remove of a node.

2022-12-31T12:26:08+00:00

[ Upstream commit 0c74d9f79ec4299365bbe803baa736ae0068179e ] Due to the hashed-MAC optimisation one problem become visible: hsr_handle_sup_frame() walks over the list of available nodes and merges two node entries into one if based on the information in the supervision both MAC addresses belong to one node. The list-walk happens on a RCU protected list and delete operation happens under a lock. If the supervision arrives on both slave interfaces at the same time then this delete operation can occur simultaneously on two CPUs. The result is the first-CPU deletes the from the list and the second CPUs BUGs while attempting to dereference a poisoned list-entry. This happens more likely with the optimisation because a new node for the mac_B entry is created once a packet has been received and removed (merged) once the supervision frame has been received. Avoid removing/ cleaning up a hsr_node twice by adding a `removed' field which is set to true after the removal and checked before the removal. Fixes: f266a683a4804 ("net/hsr: Better frame dispatch") Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

hsr: Add a rcu-read lock to hsr_forward_skb().

2022-12-31T12:26:08+00:00

[ Upstream commit 5aa2820177af650293b2f9f1873c1f6f8e4ad7a4 ] hsr_forward_skb() a skb and keeps information in an on-stack hsr_frame_info. hsr_get_node() assigns hsr_frame_info::node_src which is from a RCU list. This pointer is used later in hsr_forward_do(). I don't see a reason why this pointer can't vanish midway since there is no guarantee that hsr_forward_skb() is invoked from an RCU read section. Use rcu_read_lock() to protect hsr_frame_info::node_src from its assignment until it is no longer used. Fixes: f266a683a4804 ("net/hsr: Better frame dispatch") Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

Revert "net: hsr: use hlist_head instead of list_head for mac addresses"

2022-12-31T12:26:08+00:00

[ Upstream commit e012764cebf6e33097f6833ff15a936fbe7b846c ] The hlist optimisation (which not only uses hlist_head instead of list_head but also splits hsr_priv::node_db into an array of 256 slots) does not consider the "node merge": Upon starting the hsr network (with three nodes) a packet that is sent from node1 to node3 will also be sent from node1 to node2 and then forwarded to node3. As a result node3 will receive 2 packets because it is not able to filter out the duplicate. Each packet received will create a new struct hsr_node with macaddress_A only set the MAC address it received from (the two MAC addesses from node1). At some point (early in the process) two supervision frames will be received from node1. They will be processed by hsr_handle_sup_frame() and one frame will leave early ("Node has already been merged") and does nothing. The other frame will be merged as portB and have its MAC address written to macaddress_B and the hsr_node (that was created for it as macaddress_A) will be removed. From now on HSR is able to identify a duplicate because both packets sent from one node will result in the same struct hsr_node because hsr_get_node() will find the MAC address either on macaddress_A or macaddress_B. Things get tricky with the optimisation: If sender's MAC address is saved as macaddress_A then the lookup will work as usual. If the MAC address has been merged into macaddress_B of another hsr_node then the lookup won't work because it is likely that the data structure is in another bucket. This results in creating a new struct hsr_node and not recognising a possible duplicate. A way around it would be to add another hsr_node::mac_list_B and attach it to the other bucket to ensure that this hsr_node will be looked up either via macaddress_A _or_ macaddress_B. I however prefer to revert it because it sounds like an academic problem rather than real life workload plus it adds complexity. I'm not an HSR expert with what is usual size of a network but I would guess 40 to 60 nodes. With 10.000 nodes and assuming 60us for pass-through (from node to node) then it would take almost 600ms for a packet to almost wrap around which sounds a lot. Revert the hash MAC addresses optimisation. Fixes: 4acc45db71158 ("net: hsr: use hlist_head instead of list_head for mac addresses") Cc: Juhee Kang Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

net: hsr: Fix potential use-after-free

2022-12-08T10:30:17+00:00

[ Upstream commit 7e177d32442b7ed08a9fa61b61724abc548cb248 ] The skb is delivered to netif_rx() which may free it, after calling this, dereferencing skb may trigger use-after-free. Fixes: f421436a591d ("net/hsr: Add support for the High-availability Seamless Redundancy protocol (HSRv0)") Signed-off-by: YueHaibing Link: https://lore.kernel.org/r/20221125075724.27912-1-yuehaibing@huawei.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

net: hsr: avoid possible NULL deref in skb_clone()

2022-10-29T08:08:34+00:00

[ Upstream commit d8b57135fd9ffe9a5b445350a686442a531c5339 ] syzbot got a crash [1] in skb_clone(), caused by a bug in hsr_get_untagged_frame(). When/if create_stripped_skb_hsr() returns NULL, we must not attempt to call skb_clone(). While we are at it, replace a WARN_ONCE() by netdev_warn_once(). [1] general protection fault, probably for non-canonical address 0xdffffc000000000f: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000078-0x000000000000007f] CPU: 1 PID: 754 Comm: syz-executor.0 Not tainted 6.0.0-syzkaller-02734-g0326074ff465 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022 RIP: 0010:skb_clone+0x108/0x3c0 net/core/skbuff.c:1641 Code: 93 02 00 00 49 83 7c 24 28 00 0f 85 e9 00 00 00 e8 5d 4a 29 fa 4c 8d 75 7e 48 b8 00 00 00 00 00 fc ff df 4c 89 f2 48 c1 ea 03 <0f> b6 04 02 4c 89 f2 83 e2 07 38 d0 7f 08 84 c0 0f 85 9e 01 00 00 RSP: 0018:ffffc90003ccf4e0 EFLAGS: 00010207 RAX: dffffc0000000000 RBX: ffffc90003ccf5f8 RCX: ffffc9000c24b000 RDX: 000000000000000f RSI: ffffffff8751cb13 RDI: 0000000000000000 RBP: 0000000000000000 R08: 00000000000000f0 R09: 0000000000000140 R10: fffffbfff181d972 R11: 0000000000000000 R12: ffff888161fc3640 R13: 0000000000000a20 R14: 000000000000007e R15: ffffffff8dc5f620 FS: 00007feb621e4700(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007feb621e3ff8 CR3: 00000001643a9000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: hsr_get_untagged_frame+0x4e/0x610 net/hsr/hsr_forward.c:164 hsr_forward_do net/hsr/hsr_forward.c:461 [inline] hsr_forward_skb+0xcca/0x1d50 net/hsr/hsr_forward.c:623 hsr_handle_frame+0x588/0x7c0 net/hsr/hsr_slave.c:69 __netif_receive_skb_core+0x9fe/0x38f0 net/core/dev.c:5379 __netif_receive_skb_one_core+0xae/0x180 net/core/dev.c:5483 __netif_receive_skb+0x1f/0x1c0 net/core/dev.c:5599 netif_receive_skb_internal net/core/dev.c:5685 [inline] netif_receive_skb+0x12f/0x8d0 net/core/dev.c:5744 tun_rx_batched+0x4ab/0x7a0 drivers/net/tun.c:1544 tun_get_user+0x2686/0x3a00 drivers/net/tun.c:1995 tun_chr_write_iter+0xdb/0x200 drivers/net/tun.c:2025 call_write_iter include/linux/fs.h:2187 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x9e9/0xdd0 fs/read_write.c:584 ksys_write+0x127/0x250 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Fixes: f266a683a480 ("net/hsr: Better frame dispatch") Reported-by: syzbot Signed-off-by: Eric Dumazet Link: https://lore.kernel.org/r/20221017165928.2150130-1-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

treewide: Replace GPLv2 boilerplate/reference with SPDX - gpl-2.0_30.RULE (part 2)

2022-06-10T12:51:35+00:00

Based on the normalized pattern: this program is free software you can redistribute it and/or modify it under the terms of the gnu general public license as published by the free software foundation version 2 this program is distributed as is without any warranty of any kind whether express or implied without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference. Reviewed-by: Allison Randal Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

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